AI Trajectory

null

{
  "EnableConfigs": [
    "NFC",
    "NFC_HCI",
    "NFC_SHDLC"
  ],
  "FocusSymbols": [
    "nfc_hci_create_pipe",
    "nfc_hci_connect_gate",
    "hci_dev_connect_gates",
    "hci_dev_session_init"
  ],
  "KMSANReasoning": "The patch adds validation checks in `nfc_hci_create_pipe()`:\n1. It verifies that `skb-\u003elen \u003e= sizeof(*resp)` before dereferencing `resp-\u003epipe`, preventing an out-of-bounds read on a truncated skb buffer.\n2. It verifies that `pipe \u003c NFC_HCI_MAX_PIPES`, preventing an out-of-bounds array indexing bug when `hdev-\u003epipes[pipe]` is subsequently accessed in `nfc_hci_connect_gate()`.\n\nThese issues are classical out-of-bounds read/write memory safety vulnerabilities that are detected by KASAN. The patch does not introduce or modify any uninitialized variables, stack/heap allocations, padding bytes, or user-space copies (info-leaks). Therefore, a dedicated KMSAN fuzzing session is not warranted.",
  "NeedsKMSAN": false,
  "Reasoning": "The patch adds length and bounds checks in nfc_hci_create_pipe() to prevent out-of-bounds reads and writes when processing response frames from an NFC controller. This executable networking code is reachable during NFC HCI device initialization and session management, warranting fuzzing to ensure robustness against malformed responses.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit 923dbc502cd0d0256b3b662a960a0ed0c59bdd91\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Sat Sep 12 12:09:05 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/nfc/hci/command.c b/net/nfc/hci/command.c\nindex af6bacb3ba986..9c8bcb98b9677 100644\n--- a/net/nfc/hci/command.c\n+++ b/net/nfc/hci/command.c\n@@ -225,10 +225,19 @@ static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,\n \tif (*result \u003c 0)\n \t\treturn NFC_HCI_INVALID_PIPE;\n \n+\tif (skb-\u003elen \u003c sizeof(*resp)) {\n+\t\tkfree_skb(skb);\n+\t\t*result = -EPROTO;\n+\t\treturn NFC_HCI_INVALID_PIPE;\n+\t}\n \tresp = (struct hci_create_pipe_resp *)skb-\u003edata;\n \tpipe = resp-\u003epipe;\n \tkfree_skb(skb);\n \n+\tif (pipe \u003e= NFC_HCI_MAX_PIPES) {\n+\t\t*result = -EINVAL;\n+\t\treturn NFC_HCI_INVALID_PIPE;\n+\t}\n \tpr_debug(\"pipe created=%d\\n\", pipe);\n \n \treturn pipe;\n"
}

core

null

{
  "EnableConfigs": [
    "NFC",
    "NFC_HCI",
    "NFC_SHDLC"
  ],
  "FocusSymbols": [
    "nfc_hci_create_pipe",
    "nfc_hci_connect_gate",
    "hci_dev_connect_gates",
    "hci_dev_session_init"
  ],
  "Reasoning": "The patch adds length and bounds checks in nfc_hci_create_pipe() to prevent out-of-bounds reads and writes when processing response frames from an NFC controller. This executable networking code is reachable during NFC HCI device initialization and session management, warranting fuzzing to ensure robustness against malformed responses.",
  "WorthFuzzing": true
}

You are an expert Linux kernel maintainer and security engineer.
Your job is to review a provided patch series and evaluate whether it warrants fuzzing with syzkaller.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on internal assumptions. You must actively use your code access
tools to inspect the actual source code, callers, and surrounding context.

================================================================================
1. CORE TRIAGE PHILOSOPHY
================================================================================
The goal of patch fuzzing is to discover crashes, regressions, exposed latent bugs,
and newly triggered assertions introduced by the patch series.

- REACHABILITY IS THE PRIMARY GATE:
  Fuzzing can only discover bugs in code that can actually execute in standard virtualized
  environments (GCE or QEMU, utilizing software-emulated devices like USB gadgets, netdev, tun/tap).
  If the modified code is structurally unreachable (see Section 2), it MUST NOT be fuzzed,
  regardless of whether it adds assertions or complex logic.

- DO NOT BLINDLY TRUST "NO FUNCTIONAL CHANGE" (NFCI) OR "REFACTORING" CLAIMS:
  Patch authors routinely label changes as "cleanups", "refactorings", or state
  "No functional change intended". Do NOT take these claims at face value.
  Code refactorings that rearrange logic, introduce helper functions, or alter state management
  in core subsystems frequently introduce subtle semantic shifts or uncover latent kernel bugs.
  If reachable executable code is modified or refactored, it MUST be fuzzed.

- NEW OR MODIFIED ASSERTIONS IN REACHABLE CODE MUST BE FUZZED:
  When a patch introduces or modifies runtime checks or assertions (e.g., WARN_ON*, VM_WARN_ON*,
  BUG_ON*, lockdep_assert*) in reachable code paths, it enforces new or stricter invariants.
  Even if the author believes the invariant always holds, fuzzing is essential to verify whether
  an unusual sequence of operations can violate it.

================================================================================
2. WHEN TO RETURN WorthFuzzing=false (NEGATIVE CRITERIA)
================================================================================
Return WorthFuzzing=false ONLY IF all modified code falls strictly into one or more of these categories:

- Non-kernel and non-executable changes:
  * Modifications to Documentation/, comments, or spelling fixes.
  * User-space directories, self-tests, samples, or scripts (e.g., tools/, samples/, scripts/, usr/)
    that do not affect the compiled kernel image (vmlinux) or kernel modules.
  * Purely decorative logging (e.g., message strings in pr_err, printk, dev_info) or tracepoints
    that do not alter control flow or data structures.
  * Build system or Kconfig changes that do not alter compiled C logic.
- Structurally unreachable hardware:
  * Vendor-specific PCIe switches, SmartNICs, or GPU drivers (e.g., mlxsw, pds_core, qed,
    ionic, amdgpu) requiring physical ASIC/PCIe cards not emulated in standard QEMU.
- Unreachable execution paths:
  * Driver teardown callbacks (.remove, .shutdown, pci_unregister_driver) executed only during
    physical PCI hot-unplug or manual sysfs driver unbinding.
  * Code paths exclusive to architectures other than the target architecture.

================================================================================
3. WHEN TO RETURN WorthFuzzing=true (POSITIVE CRITERIA)
================================================================================
Return WorthFuzzing=true whenever the patch touches reachable executable code, including:
- Core Subsystems:
  * Any logic modifications in memory management (mm/), synchronization/locking (kernel/locking/),
    BPF, scheduler, core networking, VFS, or syscall handling.
- Refactorings and Code Cleanups:
  * Any restructuring of reachable data structures, helper abstractions, or algorithm flows.
- Runtime Assertions and Defensive Checks:
  * Any introduction or alteration of assertions (WARN_ON*, VM_WARN_ON*, BUG_ON*, etc.) in reachable paths.
- Reachable Drivers and Protocols:
  * Drivers accessible via virtual buses (virtio, USB gadget, loopback, netlink, binder, sockets, etc.).

================================================================================
4. EXTRACTING FocusSymbols (PREVENTING DILUTION)
================================================================================
When WorthFuzzing=true, you must extract specific kernel functions into FocusSymbols to guide the fuzzer:

- AVOID UBIQUITOUS LIFECYCLE HOT-PATHS:
  Do NOT list generic, ubiquitous functions called by almost every program in the corpus
  (including, but not limited to: general memory allocators and deallocators, page fault
  and trap handlers, or core synchronization primitives; this is not an exhaustive list).
  Listing ubiquitous functions causes the fuzzer to classify thousands of unrelated tests as "focused",
  which severely dilutes fuzzing effort away from the actual changes.

- TARGET SPECIFIC FEATURE LOGIC AND ENTRYPOINTS:
  List functions that specifically implement the logic being added or altered, or direct API entrypoints
  for the subsystem feature under review.

- HANDLING STATIC INLINE FUNCTIONS IN HEADERS (.h):
  Compiler-inlined static functions (such as static inlines in mm/*.h or include/linux/*.h) lack
  distinct symbol addresses in vmlinux and cannot be targeted directly by symbol coverage filters.
  If the changes are primarily in static inline helpers, identify non-static, feature-specific caller
  functions in .c files that exercise them (avoiding ubiquitous lifecycle wrappers).

================================================================================
5. IDENTIFYING EnableConfigs
================================================================================
Identify any specific CONFIG_ options required to properly compile and reach the modified code:
- Inspect Kconfig files and #ifdef guards; do not make assumptions.
- Check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed.
- Strip any 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4").
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

Target architecture: amd64

For your convenience, here is the diff of the changes:
commit 923dbc502cd0d0256b3b662a960a0ed0c59bdd91
Author: syz-cluster <triage@syzkaller.com>
Date:   Sat Sep 12 12:09:05 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/nfc/hci/command.c b/net/nfc/hci/command.c
index af6bacb3ba986..9c8bcb98b9677 100644
--- a/net/nfc/hci/command.c
+++ b/net/nfc/hci/command.c
@@ -225,10 +225,19 @@ static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
 	if (*result < 0)
 		return NFC_HCI_INVALID_PIPE;
 
+	if (skb->len < sizeof(*resp)) {
+		kfree_skb(skb);
+		*result = -EPROTO;
+		return NFC_HCI_INVALID_PIPE;
+	}
 	resp = (struct hci_create_pipe_resp *)skb->data;
 	pipe = resp->pipe;
 	kfree_skb(skb);
 
+	if (pipe >= NFC_HCI_MAX_PIPES) {
+		*result = -EINVAL;
+		return NFC_HCI_INVALID_PIPE;
+	}
 	pr_debug("pipe created=%d\n", pipe);
 
 	return pipe;

gemini-3.8-flash

null

null

							input: 2983
							output: 38
							thoughts: 305
						

**Analyzing a Kernel NFC Patch**

Okay, let's dive into this. The patch is touching `net/nfc/hci/command.c`, specifically the `nfc_hci_create_pipe` function. I see two new checks added within the function. First, a size check on the received `skb` (socket buffer) to ensure it's large enough to hold the `hci_create_pipe_resp` structure. It's a good defensive measure to prevent potential out-of-bounds reads if the response is truncated, resulting in a `-EPROTO` error and `NFC_HCI_INVALID_PIPE` return. Smart.

Then, there's a check on the `pipe` value extracted from the response. It now validates that the assigned `pipe` doesn't exceed `NFC_HCI_MAX_PIPES`, returning `-EINVAL` and `NFC_HCI_INVALID_PIPE` if the pipe index is out of bounds. This is another essential check for data integrity and error handling, preventing potential resource exhaustion or buffer overflows.

To get the full picture, I should probably understand the context around this function within the HCI framework. Let me quickly use `read-file` or `grepper` on the file to get a broader view of the surrounding code and how this `create_pipe` function is being used. This kind of patch usually stems from a specific issue or vulnerability, so it will be good to understand the motivation behind it. These checks look solid, but context is key to fully appreciating the patch's impact.

{
  "File": "net/nfc/hci/command.c",
  "FirstLine": 210,
  "LineCount": 50
}

{
  "Contents": " 210:\t{\n 211:\t\tstruct sk_buff *skb;\n 212:\t\tstruct hci_create_pipe_params params;\n 213:\t\tstruct hci_create_pipe_resp *resp;\n 214:\t\tu8 pipe;\n 215:\t\n 216:\t\tpr_debug(\"gate=%d\\n\", dest_gate);\n 217:\t\n 218:\t\tparams.src_gate = NFC_HCI_ADMIN_GATE;\n 219:\t\tparams.dest_host = dest_host;\n 220:\t\tparams.dest_gate = dest_gate;\n 221:\t\n 222:\t\t*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\n 223:\t\t\t\t\t      NFC_HCI_ADM_CREATE_PIPE,\n 224:\t\t\t\t\t      (u8 *) \u0026params, sizeof(params), \u0026skb);\n 225:\t\tif (*result \u003c 0)\n 226:\t\t\treturn NFC_HCI_INVALID_PIPE;\n 227:\t\n 228:\t\tif (skb-\u003elen \u003c sizeof(*resp)) {\n 229:\t\t\tkfree_skb(skb);\n 230:\t\t\t*result = -EPROTO;\n 231:\t\t\treturn NFC_HCI_INVALID_PIPE;\n 232:\t\t}\n 233:\t\tresp = (struct hci_create_pipe_resp *)skb-\u003edata;\n 234:\t\tpipe = resp-\u003epipe;\n 235:\t\tkfree_skb(skb);\n 236:\t\n 237:\t\tif (pipe \u003e= NFC_HCI_MAX_PIPES) {\n 238:\t\t\t*result = -EINVAL;\n 239:\t\t\treturn NFC_HCI_INVALID_PIPE;\n 240:\t\t}\n 241:\t\tpr_debug(\"pipe created=%d\\n\", pipe);\n 242:\t\n 243:\t\treturn pipe;\n 244:\t}\n 245:\t\n 246:\tstatic int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)\n 247:\t{\n 248:\t\treturn nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\n 249:\t\t\t\t\t   NFC_HCI_ADM_DELETE_PIPE, \u0026pipe, 1, NULL);\n 250:\t}\n 251:\t\n 252:\tstatic int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)\n 253:\t{\n 254:\t\tu8 param[2];\n 255:\t\tsize_t param_len = 2;\n 256:\t\n 257:\t\t/* TODO: Find out what the identity reference data is\n 258:\t\t * and fill param with it. HCI spec 6.1.3.5 */\n 259:\t\n"
}

gemini-3.8-flash

null

null

							input: 4438
							output: 38
							thoughts: 57
						

**Investigating the `nfc_hci_create_pipe` Function**

Okay, so I need to understand the call structure of `nfc_hci_create_pipe`. My first step will be to identify all the functions that directly call it. I'll need to use some code navigation tools, perhaps grep or a more sophisticated IDE search, to track down the callers. Once I've got that list, I can start to build a picture of *why* and *how* this pipe creation is happening in the overall NFC HCI architecture.

To give me a better understanding of its operation, I need to read the code surrounding this function. A quick look suggests lines 190-230 in `net/nfc/hci/command.c` should be useful. I'll focus on that section initially to see the context and any key data structures involved in the pipe creation process. That will allow me to assess how it's used and any potential issues this function may be the cause of.

{
  "File": "net/nfc/hci/command.c",
  "FirstLine": 190,
  "LineCount": 40
}

{
  "Contents": " 190:\t\t\t\t\tNULL, 0, \u0026skb);\n 191:\t\tif (r == 0) {\n 192:\t\t\t/* dest host other than host controller will send\n 193:\t\t\t * number of pipes already open on this gate before\n 194:\t\t\t * execution. The number can be found in skb-\u003edata[0]\n 195:\t\t\t */\n 196:\t\t\tkfree_skb(skb);\n 197:\t\t}\n 198:\t\n 199:\t\treturn r;\n 200:\t}\n 201:\t\n 202:\tstatic int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)\n 203:\t{\n 204:\t\treturn nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,\n 205:\t\t\t\t\t   NULL, 0, NULL);\n 206:\t}\n 207:\t\n 208:\tstatic u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,\n 209:\t\t\t\t      u8 dest_gate, int *result)\n 210:\t{\n 211:\t\tstruct sk_buff *skb;\n 212:\t\tstruct hci_create_pipe_params params;\n 213:\t\tstruct hci_create_pipe_resp *resp;\n 214:\t\tu8 pipe;\n 215:\t\n 216:\t\tpr_debug(\"gate=%d\\n\", dest_gate);\n 217:\t\n 218:\t\tparams.src_gate = NFC_HCI_ADMIN_GATE;\n 219:\t\tparams.dest_host = dest_host;\n 220:\t\tparams.dest_gate = dest_gate;\n 221:\t\n 222:\t\t*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\n 223:\t\t\t\t\t      NFC_HCI_ADM_CREATE_PIPE,\n 224:\t\t\t\t\t      (u8 *) \u0026params, sizeof(params), \u0026skb);\n 225:\t\tif (*result \u003c 0)\n 226:\t\t\treturn NFC_HCI_INVALID_PIPE;\n 227:\t\n 228:\t\tif (skb-\u003elen \u003c sizeof(*resp)) {\n 229:\t\t\tkfree_skb(skb);\n"
}

gemini-3.8-flash

null

null

							input: 5382
							output: 22
							thoughts: 20
						

Okay, here's my take on those thoughts, framed as a first-person expert summary:

**Analyzing `nfc_hci_create_pipe` Callers**

Alright, time to get to work. My immediate thought is to trace the callers of the `nfc_hci_create_pipe` function across the codebase. This is a critical first step. By identifying where this function is being invoked, I can begin to understand its context, its intended use cases, and, potentially, pinpoint areas that might be experiencing issues or need optimization.

I’ll be looking for several key things as I review these calls. First, I'm interested in the *purpose* behind each pipe creation. Is it for standard data exchange, secure communication, or something more specialized? The different use-cases would be key. Secondly, I'll pay close attention to the parameters being passed to the function – especially the pipe type and the associated attributes. This will give me clues about the expected behavior of each established pipe. Are there any inconsistencies in the parameter usage that might hint at a bug or inefficiency?

Beyond the immediate context, I'll be keeping an eye out for potential design patterns. Are there common approaches to pipe initialization, management, and teardown? Are there redundant calls or situations where pipe creation might be happening unnecessarily? The goal here isn't just to list the calls, it's to develop a deeper understanding of the system's overall architecture and how these NFC pipes are integrated within it. This will help me with my next step, which would be to look for potential bottlenecks or vulnerabilities within the whole system.

{
  "Expression": "nfc_hci_create_pipe"
}

{
  "Output": "net/nfc/hci/command.c=202=static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)\n--\nnet/nfc/hci/command.c-207-\nnet/nfc/hci/command.c:208:static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,\nnet/nfc/hci/command.c-209-\t\t\t      u8 dest_gate, int *result)\n--\nnet/nfc/hci/command.c=306=int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,\n--\nnet/nfc/hci/command.c-328-\tdefault:\nnet/nfc/hci/command.c:329:\t\tpipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, \u0026r);\nnet/nfc/hci/command.c-330-\t\tif (pipe == NFC_HCI_INVALID_PIPE)\n"
}

gemini-3.8-flash

null

null

							input: 6049
							output: 22
							thoughts: 16
						

Okay, here's my summary, tailored as if I'm an expert in this field thinking through the problem:

**Tracing the Calls to `nfc_hci_connect_gate`**

Alright, so the task at hand is to understand the calling contexts of `nfc_hci_connect_gate`. As an expert in this, my initial approach is to immediately start thinking about the potential areas where such a function call would be logical within the NFC HCI stack. This function likely manages a connection "gate," so I'm envisioning the potential scenarios right now:

*   **Connection Establishment:** Obviously, this is the most direct possibility. I'm visualizing the standard connection setup flows – are we talking about a new device connection, maybe a connection to a specific tag or reader? Or a re-establishment after some kind of disruption? The different types of connections would determine the likely call sites.
*   **Gate Management:** Is this "gate" more of a logical construct within the driver, maybe tied to a specific physical channel or connection type? I'm trying to mentally map out the driver's architecture – is it layered? Are there different "gates" for different types of connections or operations?
*   **Error Handling/Recovery:** A more nuanced possibility is that this function gets called as part of error handling or recovery procedures. If a connection breaks down or experiences issues, is it possible that reconnecting, or opening a new "gate," is part of the recovery process? I need to consider scenarios like link loss, buffer overflows, or authentication failures.
*   **Power Management:** Considering low-power states, is there a potential for the function being involved in managing and creating gates when the device needs to come back to a specific state, which would be a critical point, and how these gates relate to those low-power states?

I'm starting to build a mental map of the possible call paths. I'll need to use my tools - the trace data or the code itself - to confirm these hypotheses. I'm anticipating that understanding the various contexts will be key to understanding the full picture of the functions purpose, its function parameters, and its role in the driver's overall operation.

{
  "Expression": "nfc_hci_connect_gate"
}

{
  "Output": "drivers/nfc/st21nfca/core.c=104=static int st21nfca_hci_load_session(struct nfc_hci_dev *hdev)\n--\ndrivers/nfc/st21nfca/core.c-133-\t */\ndrivers/nfc/st21nfca/core.c:134:\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\ndrivers/nfc/st21nfca/core.c-135-\t\t\t\tST21NFCA_DEVICE_MGNT_GATE,\n--\ndrivers/nfc/st21nfca/core.c-196-\t */\ndrivers/nfc/st21nfca/core.c:197:\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\ndrivers/nfc/st21nfca/core.c-198-\t\t\t\t NFC_HCI_LINK_MGMT_GATE,\n--\ninclude/net/nfc/hci.h=254=void nfc_hci_recv_frame(struct nfc_hci_dev *hdev, struct sk_buff *skb);\n--\ninclude/net/nfc/hci.h-256-/* connecting to gates and sending hci instructions */\ninclude/net/nfc/hci.h:257:int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,\ninclude/net/nfc/hci.h-258-\t\t\t u8 pipe);\n--\nnet/nfc/hci/command.c=304=EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);\nnet/nfc/hci/command.c-305-\nnet/nfc/hci/command.c:306:int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,\nnet/nfc/hci/command.c-307-\t\t\t u8 pipe)\n--\nnet/nfc/hci/command.c-352-}\nnet/nfc/hci/command.c:353:EXPORT_SYMBOL(nfc_hci_connect_gate);\n--\nnet/nfc/hci/core.c=449=static int hci_dev_connect_gates(struct nfc_hci_dev *hdev, u8 gate_count,\n--\nnet/nfc/hci/core.c-453-\twhile (gate_count--) {\nnet/nfc/hci/core.c:454:\t\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\nnet/nfc/hci/core.c-455-\t\t\t\t\t gates-\u003egate, gates-\u003epipe);\n--\nnet/nfc/hci/core.c=464=static int hci_dev_session_init(struct nfc_hci_dev *hdev)\n--\nnet/nfc/hci/core.c-471-\nnet/nfc/hci/core.c:472:\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\nnet/nfc/hci/core.c-473-\t\t\t\t hdev-\u003einit_data.gates[0].gate,\n"
}

gemini-3.8-flash

null

null

							input: 7390
							output: 21
							thoughts: 41
						

**Investigating the NFC HCI Initialization Process**

Okay, so I need to understand the NFC HCI initialization sequence, particularly how `hci_dev_session_init` fits into the picture and how the NFC HCI itself gets triggered and utilized. My initial instinct is to dig into the core implementation, so I'll start by examining `net/nfc/hci/core.c`. Hopefully, the code there will shed light on the initial setup and subsequent interactions. I expect to find the central logic for the HCI framework within this file. Let's get to it.

{
  "Expression": "hci_dev_session_init"
}

{
  "Output": "drivers/nfc/st-nci/se.c=545=static int st_nci_hci_network_init(struct nci_dev *ndev)\n--\ndrivers/nfc/st-nci/se.c-593-\ndrivers/nfc/st-nci/se.c:594:\tr = nci_hci_dev_session_init(ndev);\ndrivers/nfc/st-nci/se.c-595-\tif (r != NCI_HCI_ANY_OK)\n--\ninclude/net/nfc/nci_core.h=321=int nci_hci_clear_all_pipes(struct nci_dev *ndev);\ninclude/net/nfc/nci_core.h:322:int nci_hci_dev_session_init(struct nci_dev *ndev);\ninclude/net/nfc/nci_core.h-323-\n--\nnet/nfc/hci/core.c=449=static int hci_dev_connect_gates(struct nfc_hci_dev *hdev, u8 gate_count,\n--\nnet/nfc/hci/core.c-463-\nnet/nfc/hci/core.c:464:static int hci_dev_session_init(struct nfc_hci_dev *hdev)\nnet/nfc/hci/core.c-465-{\n--\nnet/nfc/hci/core.c=579=static int hci_dev_up(struct nfc_dev *nfc_dev)\n--\nnet/nfc/hci/core.c-593-\nnet/nfc/hci/core.c:594:\tr = hci_dev_session_init(hdev);\nnet/nfc/hci/core.c-595-\tif (r \u003c 0)\n--\nnet/nfc/nci/hci.c=706=static int nci_hci_dev_connect_gates(struct nci_dev *ndev,\n--\nnet/nfc/nci/hci.c-722-\nnet/nfc/nci/hci.c:723:int nci_hci_dev_session_init(struct nci_dev *ndev)\nnet/nfc/nci/hci.c-724-{\n--\nnet/nfc/nci/hci.c-783-}\nnet/nfc/nci/hci.c:784:EXPORT_SYMBOL(nci_hci_dev_session_init);\nnet/nfc/nci/hci.c-785-\n"
}

gemini-3.8-flash

null

null

							input: 8223
							output: 38
							thoughts: 67
						

Here's my summary, as though I'm thinking through this process:

**Diving into the NFC HCI Driver Initialization**

Okay, so `hci_dev_up` is the `.dev_up` callback for the `nfc_dev` structure. Right, that makes perfect sense. Time to track down where this is all wired up. Let's see... the `hci_dev_up` function is registered in `net/nfc/hci/core.c`. Excellent, that's precisely what I need. I'll open that file up and start tracing the execution path from there. This is likely where the core HCI device initialization logic resides and will give me the entry point I'm looking for to understand how things are brought online. Time to dive into the code and see what `core.c` has in store!

{
  "File": "net/nfc/hci/core.c",
  "FirstLine": 575,
  "LineCount": 40
}

{
  "Contents": " 575:\t\n 576:\t\treturn 0;\n 577:\t}\n 578:\t\n 579:\tstatic int hci_dev_up(struct nfc_dev *nfc_dev)\n 580:\t{\n 581:\t\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\n 582:\t\tint r = 0;\n 583:\t\n 584:\t\tif (hdev-\u003eops-\u003eopen) {\n 585:\t\t\tr = hdev-\u003eops-\u003eopen(hdev);\n 586:\t\t\tif (r \u003c 0)\n 587:\t\t\t\treturn r;\n 588:\t\t}\n 589:\t\n 590:\t\tr = nfc_llc_start(hdev-\u003ellc);\n 591:\t\tif (r \u003c 0)\n 592:\t\t\tgoto exit_close;\n 593:\t\n 594:\t\tr = hci_dev_session_init(hdev);\n 595:\t\tif (r \u003c 0)\n 596:\t\t\tgoto exit_llc;\n 597:\t\n 598:\t\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\n 599:\t\t\t\t       NFC_HCI_EVT_END_OPERATION, NULL, 0);\n 600:\t\tif (r \u003c 0)\n 601:\t\t\tgoto exit_llc;\n 602:\t\n 603:\t\tif (hdev-\u003eops-\u003ehci_ready) {\n 604:\t\t\tr = hdev-\u003eops-\u003ehci_ready(hdev);\n 605:\t\t\tif (r \u003c 0)\n 606:\t\t\t\tgoto exit_llc;\n 607:\t\t}\n 608:\t\n 609:\t\tr = hci_dev_version(hdev);\n 610:\t\tif (r \u003c 0)\n 611:\t\t\tgoto exit_llc;\n 612:\t\n 613:\t\treturn 0;\n 614:\t\n"
}

gemini-3.8-flash

null

null

							input: 9069
							output: 22
							thoughts: 68
						

Here's my take on those thoughts:

**Analyzing the HCI Device Bring-Up**

Okay, so `hci_dev_up` is triggered by a `NFC_CMD_DEV_UP` command coming from userspace through netlink, specifically the generic netlink NFC interface. That makes sense, standard control flow. Now, the key question is: what actually *uses* the functions `nfc_hci_allocate_device` and `nfc_hci_register_device`? I need to understand which hardware drivers or subsystems are responsible for claiming and managing these HCI devices. I'm going to dig into the code and trace where those functions are called to get a clearer picture of the device registration process. Let's see what the code reveals!

{
  "Expression": "nfc_hci_allocate_device"
}

{
  "Output": "drivers/nfc/microread/microread.c=670=int microread_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\n--\ndrivers/nfc/microread/microread.c-702-\ndrivers/nfc/microread/microread.c:703:\tinfo-\u003ehdev = nfc_hci_allocate_device(\u0026microread_hci_ops, \u0026init_data,\ndrivers/nfc/microread/microread.c-704-\t\t\t\t\t     quirks, protocols, llc_name,\n--\ndrivers/nfc/pn544/pn544.c=903=int pn544_hci_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\n--\ndrivers/nfc/pn544/pn544.c-941-\ndrivers/nfc/pn544/pn544.c:942:\tinfo-\u003ehdev = nfc_hci_allocate_device(\u0026pn544_hci_ops, \u0026init_data, 0,\ndrivers/nfc/pn544/pn544.c-943-\t\t\t\t\t     protocols, llc_name,\n--\ndrivers/nfc/st21nfca/core.c=937=int st21nfca_hci_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\n--\ndrivers/nfc/st21nfca/core.c-987-\tinfo-\u003ehdev =\ndrivers/nfc/st21nfca/core.c:988:\t    nfc_hci_allocate_device(\u0026st21nfca_hci_ops, \u0026init_data, quirks,\ndrivers/nfc/st21nfca/core.c-989-\t\t\t\t    protocols, llc_name,\n--\ninclude/net/nfc/hci.h=99=struct nfc_hci_dev {\n--\ninclude/net/nfc/hci.h-153-/* hci device allocation */\ninclude/net/nfc/hci.h:154:struct nfc_hci_dev *nfc_hci_allocate_device(const struct nfc_hci_ops *ops,\ninclude/net/nfc/hci.h-155-\t\t\t\t\t    struct nfc_hci_init_data *init_data,\n--\nnet/nfc/hci/core.c=941=static const struct nfc_ops hci_nfc_ops = {\n--\nnet/nfc/hci/core.c-959-\nnet/nfc/hci/core.c:960:struct nfc_hci_dev *nfc_hci_allocate_device(const struct nfc_hci_ops *ops,\nnet/nfc/hci/core.c-961-\t\t\t\t\t    struct nfc_hci_init_data *init_data,\n--\nnet/nfc/hci/core.c-1009-}\nnet/nfc/hci/core.c:1010:EXPORT_SYMBOL(nfc_hci_allocate_device);\nnet/nfc/hci/core.c-1011-\n"
}

gemini-3.8-flash

null

null

							input: 10103
							output: 22
							thoughts: 82
						

**NFC Device Investigation**

Okay, so I'm thinking about NFC device emulation and fuzzing with syzkaller. The question that's top of mind is whether there are established virtual NFC devices or USB NFC devices using the HCI protocol. Can syzkaller emulate those specifically?

My next step is to remember which drivers are relevant. I need to refresh my memory on which ones use `microread`, `pn544`, and `st21nfca`. Time to check `grepper` and see what comes up for `microread_probe`, `pn544_hci_probe`, and `st21nfca_hci_probe`. I'm hoping those probe functions will lead me to the right track.

{
  "Expression": "pn544_hci_probe"
}

{
  "Output": "drivers/nfc/pn544/i2c.c=865=static int pn544_hci_i2c_probe(struct i2c_client *client)\n--\ndrivers/nfc/pn544/i2c.c-915-\ndrivers/nfc/pn544/i2c.c:916:\tr = pn544_hci_probe(phy, \u0026i2c_phy_ops, LLC_SHDLC_NAME,\ndrivers/nfc/pn544/i2c.c-917-\t\t\t    PN544_I2C_FRAME_HEADROOM, PN544_I2C_FRAME_TAILROOM,\n--\ndrivers/nfc/pn544/mei.c=18=static int pn544_mei_probe(struct mei_cl_device *cldev,\n--\ndrivers/nfc/pn544/mei.c-27-\ndrivers/nfc/pn544/mei.c:28:\tr = pn544_hci_probe(phy, \u0026mei_phy_ops, LLC_NOP_NAME,\ndrivers/nfc/pn544/mei.c-29-\t\t\t    MEI_NFC_HEADER_SIZE, 0, MEI_NFC_MAX_HCI_PAYLOAD,\n--\ndrivers/nfc/pn544/pn544.c=883=static const struct nfc_hci_ops pn544_hci_ops = {\n--\ndrivers/nfc/pn544/pn544.c-902-\ndrivers/nfc/pn544/pn544.c:903:int pn544_hci_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\ndrivers/nfc/pn544/pn544.c-904-\t\t    char *llc_name, int phy_headroom, int phy_tailroom,\n--\ndrivers/nfc/pn544/pn544.c-970-}\ndrivers/nfc/pn544/pn544.c:971:EXPORT_SYMBOL(pn544_hci_probe);\ndrivers/nfc/pn544/pn544.c-972-\n--\ndrivers/nfc/pn544/pn544.h=16=typedef int (*fw_download_t)(void *context, const char *firmware_name,\n--\ndrivers/nfc/pn544/pn544.h-18-\ndrivers/nfc/pn544/pn544.h:19:int pn544_hci_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\ndrivers/nfc/pn544/pn544.h-20-\t\t    char *llc_name, int phy_headroom, int phy_tailroom,\n"
}

gemini-3.8-flash

null

null

							input: 11101
							output: 18
							thoughts: 7
						

Okay, here's my attempt at summarizing the thought process, tailored for an expert audience, and delivered in the first person:

**Initial Impression: Exploring a Potential Niche**

Hmm, thinking about this... a potentially interesting approach here, a concept I've been mulling over... Let's see. My mind is drawn to something I've encountered before in passing, a framework, a technique that might be relevant: `microread`. It is a rather interesting tool, and I wonder... could this be a fit? The implications are intriguing, and I am exploring the viability of how useful this could be.

{
  "Expression": "microread_probe"
}

{
  "Output": "drivers/nfc/microread/i2c.c=233=static int microread_i2c_probe(struct i2c_client *client)\n--\ndrivers/nfc/microread/i2c.c-253-\ndrivers/nfc/microread/i2c.c:254:\tr = microread_probe(phy, \u0026i2c_phy_ops, LLC_SHDLC_NAME,\ndrivers/nfc/microread/i2c.c-255-\t\t\t    MICROREAD_I2C_FRAME_HEADROOM,\n--\ndrivers/nfc/microread/mei.c=19=static int microread_mei_probe(struct mei_cl_device *cldev,\n--\ndrivers/nfc/microread/mei.c-28-\ndrivers/nfc/microread/mei.c:29:\tr = microread_probe(phy, \u0026mei_phy_ops, LLC_NOP_NAME,\ndrivers/nfc/microread/mei.c-30-\t\t\t    MEI_NFC_HEADER_SIZE, 0, MEI_NFC_MAX_HCI_PAYLOAD,\n--\ndrivers/nfc/microread/microread.c=654=static const struct nfc_hci_ops microread_hci_ops = {\n--\ndrivers/nfc/microread/microread.c-669-\ndrivers/nfc/microread/microread.c:670:int microread_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\ndrivers/nfc/microread/microread.c-671-\t\t    const char *llc_name, int phy_headroom, int phy_tailroom,\n--\ndrivers/nfc/microread/microread.c-734-}\ndrivers/nfc/microread/microread.c:735:EXPORT_SYMBOL(microread_probe);\ndrivers/nfc/microread/microread.c-736-\n--\ndrivers/nfc/microread/microread.h-12-\ndrivers/nfc/microread/microread.h:13:int microread_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\ndrivers/nfc/microread/microread.h-14-\t\t    const char *llc_name, int phy_headroom, int phy_tailroom,\n"
}

gemini-3.8-flash

null

null

							input: 11850
							output: 22
							thoughts: 119
						

**My Initial Exploration into Syzkaller and NFC Fuzzing**

Okay, hold on a second. Can Syzkaller even touch the `net/nfc/hci/command.c` file? That's the real question. I need to figure out if there's any NFC support at all within Syzkaller's reach. Does it leverage any kind of NFC interface, maybe through i2c, simulated devices, raw sockets, USB, or something similar, that would allow it to interact with the NFC HCI? I'm missing some vital context on how Syzkaller is actually fuzzing NFC.

Right, I should probably just start with a direct check. Let's dig into Syzkaller's documentation and code and explicitly look for any mention of NFC or simulated NFC devices. I'm going to start with the obvious. Let's perform a `grep` for "nfc" in both the `drivers` and `net/nfc` directories. That should give me a good overview of any available code.

Wait, is there even a virtual NFC driver? That would be a huge indicator. Okay, time to check the `drivers/nfc` directory specifically. That's the most likely place to start.

{
  "Dir": "drivers/nfc"
}

{
  "Files": [
    "mei_phy.c",
    "mei_phy.h",
    "nfcsim.c",
    "port100.c",
    "trf7970a.c",
    "virtual_ncidev.c"
  ],
  "Subdirs": [
    "fdp",
    "microread",
    "nfcmrvl",
    "nxp-nci",
    "pn533",
    "pn544",
    "s3fwrn5",
    "st-nci",
    "st21nfca",
    "st95hf"
  ]
}

gemini-3.8-flash

null

null

							input: 12392
							output: 27
							thoughts: 77
						

**NFC Driver Investigation**

Okay, so I need to get a handle on the NFC driver landscape here. Let's start by surveying the terrain. My initial thought is to look at these specific files: `drivers/nfc/virtual_ncidev.c`, `drivers/nfc/nfcsim.c`, `drivers/nfc/pn533`, and `drivers/nfc/nfcmrvl/usb.c`. That should give me a good baseline for various NFC setups.

Hold on a second... `nfcmrvl/usb.c` caught my eye. USB NFC drivers? That's an interesting angle, and possibly an indicator of the scope. Before I go too deep, let me quickly broaden the search. I should check the `drivers/nfc/` directory directly, specifically looking for any obvious USB-related files or naming conventions. It's always good to quickly scope for context, and avoid prematurely narrowing the search. This will help determine if USB is a common interface within this subsystem, or an edge case. This quick initial check will inform my next steps.

no matches

{
  "Expression": "usb_register",
  "PathPrefix": "drivers/nfc"
}

{
  "error": "no matches"
}

gemini-3.8-flash

null

null

							input: 12744
							output: 29
							thoughts: 18
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Diving into the NFC USB Driver**

Okay, so we need to see how the NFC drivers are handling USB registration. The place to start is likely `usb_register_driver`, and given the context, I'm betting the relevant code will be in `drivers/nfc`. Let's navigate there and zero in on that function call. I expect this will reveal the `usb_driver` structure's setup, the endpoints being claimed, and the device ID matching. Knowing the details of the driver's registration is key to understanding its overall behavior, any potential resource conflicts, or how it integrates into the overall USB subsystem. It should also expose how the driver handles probe and disconnect callbacks. From there, we can analyze the data transfers.

no matches

{
  "Expression": "usb_register_driver",
  "PathPrefix": "drivers/nfc"
}

{
  "error": "no matches"
}

gemini-3.8-flash

null

null

							input: 12979
							output: 29
							thoughts: 19
						

Okay, here's my take on those thoughts, framed as an expert's internal monologue:

**Investigating USB Driver Interactions within the NFC Subsystem**

Alright, time to dive into this. The task at hand is to understand how USB drivers interact within the `drivers/nfc` directory. The specific term I'm focusing on is `module_usb_driver`. This suggests we're likely dealing with a USB driver that's being dynamically loaded or managed as a module, probably related to a USB NFC reader or interface. I need to understand the control flow, the data structures used, and potential interactions with the NFC core. I anticipate finding the driver's entry points (probe, disconnect, etc.), the USB device ID tables, and likely some interaction with the NFC stack's device registration and communication mechanisms. This will be a good starting point for understanding how the USB bus is used for NFC hardware. I'll focus on how the USB driver is initialized, how it handles device attachment and detachment, and how it communicates with the NFC controller on the hardware end. Let's see what the code reveals!

{
  "Expression": "module_usb_driver",
  "PathPrefix": "drivers/nfc"
}

{
  "Output": "drivers/nfc/nfcmrvl/usb.c=440=static struct usb_driver nfcmrvl_usb_driver = {\n--\ndrivers/nfc/nfcmrvl/usb.c-453-};\ndrivers/nfc/nfcmrvl/usb.c:454:module_usb_driver(nfcmrvl_usb_driver);\ndrivers/nfc/nfcmrvl/usb.c-455-\n--\ndrivers/nfc/pn533/usb.c=622=static struct usb_driver pn533_usb_driver = {\n--\ndrivers/nfc/pn533/usb.c-628-\ndrivers/nfc/pn533/usb.c:629:module_usb_driver(pn533_usb_driver);\ndrivers/nfc/pn533/usb.c-630-\n--\ndrivers/nfc/port100.c=1629=static struct usb_driver port100_driver = {\n--\ndrivers/nfc/port100.c-1635-\ndrivers/nfc/port100.c:1636:module_usb_driver(port100_driver);\ndrivers/nfc/port100.c-1637-\n"
}

gemini-3.8-flash

null

null

							input: 13593
							output: 29
							thoughts: 132
						

**My NFC Protocol Deep Dive**

Okay, hold on a second. I need to make sure I haven't missed something fundamental here. What's the deal with `nfc_hci_recv_frame`? Does the raw socket path, AF_NFC, or netlink even *reach* the HCI layer? That's a crucial piece of the puzzle.

Alright, let's step back and identify the entry points. Let's see what functions are actually *calling* `nfc_hci_create_pipe` and `nfc_hci_connect_gate`. Those functions will give me a clear view of how the HCI layer is being utilized.

Wait a minute, I have a suspicion brewing in my mind. Is HCI mostly confined to drivers like `microread`, `pn544`, and `st21nfca`? Or is it more broadly used in the stack? This is critical for understanding the scope of my investigation.

Okay, time for a broader net. Let's find *everything* that calls `nfc_hci_create_pipe` or otherwise utilizes the `net/nfc/hci` module. I need a comprehensive list of consumers here.

Finally, I'll take a deep dive into the code itself. I'm going to do a full search for `nfc_hci` within the `net/nfc` directory. Gotta make sure I'm not missing anything in the core HCI implementation itself. This should give me a solid handle on how the entire protocol is operating.

{
  "Expression": "nfc_hci_",
  "PathPrefix": "net/nfc"
}

{
  "Output": "\nFull output is too long, showing 500 out of 575 lines.\nUse more precise expression if possible.\n\nnet/nfc/hci/command.c-18-\nnet/nfc/hci/command.c:19:static int nfc_hci_execute_cmd_async(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,\nnet/nfc/hci/command.c-20-\t\t\t       const u8 *param, size_t param_len,\n--\nnet/nfc/hci/command.c-28-\t */\nnet/nfc/hci/command.c:29:\treturn nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_COMMAND, cmd,\nnet/nfc/hci/command.c-30-\t\t\t\t      param, param_len, cb, cb_context, MAX_FWI);\n--\nnet/nfc/hci/command.c-38- */\nnet/nfc/hci/command.c:39:static void nfc_hci_execute_cb(void *context, struct sk_buff *skb, int err)\nnet/nfc/hci/command.c-40-{\n--\nnet/nfc/hci/command.c-54-\nnet/nfc/hci/command.c:55:static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,\nnet/nfc/hci/command.c-56-\t\t\t       const u8 *param, size_t param_len,\n--\nnet/nfc/hci/command.c-70-\t */\nnet/nfc/hci/command.c:71:\thcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,\nnet/nfc/hci/command.c-72-\t\t\t\t\t\t    NFC_HCI_HCP_COMMAND, cmd,\nnet/nfc/hci/command.c-73-\t\t\t\t\t\t    param, param_len,\nnet/nfc/hci/command.c:74:\t\t\t\t\t\t    nfc_hci_execute_cb, \u0026hcp_ew,\nnet/nfc/hci/command.c-75-\t\t\t\t\t\t    MAX_FWI);\n--\nnet/nfc/hci/command.c-90-\nnet/nfc/hci/command.c:91:int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,\nnet/nfc/hci/command.c-92-\t\t       const u8 *param, size_t param_len)\n--\nnet/nfc/hci/command.c-101-\nnet/nfc/hci/command.c:102:\treturn nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,\nnet/nfc/hci/command.c-103-\t\t\t\t      param, param_len, NULL, NULL, 0);\nnet/nfc/hci/command.c-104-}\nnet/nfc/hci/command.c:105:EXPORT_SYMBOL(nfc_hci_send_event);\nnet/nfc/hci/command.c-106-\n--\nnet/nfc/hci/command.c-111- */\nnet/nfc/hci/command.c:112:int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,\nnet/nfc/hci/command.c-113-\t\t     const u8 *param, size_t param_len, struct sk_buff **skb)\n--\nnet/nfc/hci/command.c-120-\nnet/nfc/hci/command.c:121:\treturn nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);\nnet/nfc/hci/command.c-122-}\nnet/nfc/hci/command.c:123:EXPORT_SYMBOL(nfc_hci_send_cmd);\nnet/nfc/hci/command.c-124-\nnet/nfc/hci/command.c:125:int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,\nnet/nfc/hci/command.c-126-\t\t\t   const u8 *param, size_t param_len,\n--\nnet/nfc/hci/command.c-134-\nnet/nfc/hci/command.c:135:\treturn nfc_hci_execute_cmd_async(hdev, pipe, cmd, param, param_len,\nnet/nfc/hci/command.c-136-\t\t\t\t\t cb, cb_context);\nnet/nfc/hci/command.c-137-}\nnet/nfc/hci/command.c:138:EXPORT_SYMBOL(nfc_hci_send_cmd_async);\nnet/nfc/hci/command.c-139-\nnet/nfc/hci/command.c:140:int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,\nnet/nfc/hci/command.c-141-\t\t      const u8 *param, size_t param_len)\n--\nnet/nfc/hci/command.c-149-\t * optimal though, and the plan is to modify APIs to pass idx down to\nnet/nfc/hci/command.c:150:\t * nfc_hci_hcp_message_tx where the frame is actually built, thereby\nnet/nfc/hci/command.c-151-\t * eliminating the need for the temp allocation-copy here.\n--\nnet/nfc/hci/command.c-162-\nnet/nfc/hci/command.c:163:\tr = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,\nnet/nfc/hci/command.c-164-\t\t\t     tmp, param_len + 1, NULL);\n--\nnet/nfc/hci/command.c-169-}\nnet/nfc/hci/command.c:170:EXPORT_SYMBOL(nfc_hci_set_param);\nnet/nfc/hci/command.c-171-\nnet/nfc/hci/command.c:172:int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,\nnet/nfc/hci/command.c-173-\t\t      struct sk_buff **skb)\n--\nnet/nfc/hci/command.c-176-\nnet/nfc/hci/command.c:177:\treturn nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,\nnet/nfc/hci/command.c-178-\t\t\t\t\u0026idx, 1, skb);\nnet/nfc/hci/command.c-179-}\nnet/nfc/hci/command.c:180:EXPORT_SYMBOL(nfc_hci_get_param);\nnet/nfc/hci/command.c-181-\nnet/nfc/hci/command.c:182:static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)\nnet/nfc/hci/command.c-183-{\n--\nnet/nfc/hci/command.c-188-\nnet/nfc/hci/command.c:189:\tr = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,\nnet/nfc/hci/command.c-190-\t\t\t\tNULL, 0, \u0026skb);\n--\nnet/nfc/hci/command.c-201-\nnet/nfc/hci/command.c:202:static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)\nnet/nfc/hci/command.c-203-{\nnet/nfc/hci/command.c:204:\treturn nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,\nnet/nfc/hci/command.c-205-\t\t\t\t   NULL, 0, NULL);\n--\nnet/nfc/hci/command.c-207-\nnet/nfc/hci/command.c:208:static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,\nnet/nfc/hci/command.c-209-\t\t\t      u8 dest_gate, int *result)\n--\nnet/nfc/hci/command.c-221-\nnet/nfc/hci/command.c:222:\t*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\nnet/nfc/hci/command.c-223-\t\t\t\t      NFC_HCI_ADM_CREATE_PIPE,\n--\nnet/nfc/hci/command.c-245-\nnet/nfc/hci/command.c:246:static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)\nnet/nfc/hci/command.c-247-{\nnet/nfc/hci/command.c:248:\treturn nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\nnet/nfc/hci/command.c-249-\t\t\t\t   NFC_HCI_ADM_DELETE_PIPE, \u0026pipe, 1, NULL);\n--\nnet/nfc/hci/command.c-251-\nnet/nfc/hci/command.c:252:static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)\nnet/nfc/hci/command.c-253-{\n--\nnet/nfc/hci/command.c-262-\nnet/nfc/hci/command.c:263:\treturn nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\nnet/nfc/hci/command.c-264-\t\t\t\t   NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,\n--\nnet/nfc/hci/command.c-267-\nnet/nfc/hci/command.c:268:int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)\nnet/nfc/hci/command.c-269-{\n--\nnet/nfc/hci/command.c-275-\nnet/nfc/hci/command.c:276:\tr = nfc_hci_close_pipe(hdev, pipe);\nnet/nfc/hci/command.c-277-\tif (r \u003c 0)\n--\nnet/nfc/hci/command.c-280-\tif (pipe != NFC_HCI_LINK_MGMT_PIPE \u0026\u0026 pipe != NFC_HCI_ADMIN_PIPE) {\nnet/nfc/hci/command.c:281:\t\tr = nfc_hci_delete_pipe(hdev, pipe);\nnet/nfc/hci/command.c-282-\t\tif (r \u003c 0)\n--\nnet/nfc/hci/command.c-289-}\nnet/nfc/hci/command.c:290:EXPORT_SYMBOL(nfc_hci_disconnect_gate);\nnet/nfc/hci/command.c-291-\nnet/nfc/hci/command.c:292:int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)\nnet/nfc/hci/command.c-293-{\n--\nnet/nfc/hci/command.c-295-\nnet/nfc/hci/command.c:296:\tr = nfc_hci_clear_all_pipes(hdev);\nnet/nfc/hci/command.c-297-\tif (r \u003c 0)\n--\nnet/nfc/hci/command.c-299-\nnet/nfc/hci/command.c:300:\tnfc_hci_reset_pipes(hdev);\nnet/nfc/hci/command.c-301-\n--\nnet/nfc/hci/command.c-303-}\nnet/nfc/hci/command.c:304:EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);\nnet/nfc/hci/command.c-305-\nnet/nfc/hci/command.c:306:int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,\nnet/nfc/hci/command.c-307-\t\t\t u8 pipe)\n--\nnet/nfc/hci/command.c-328-\tdefault:\nnet/nfc/hci/command.c:329:\t\tpipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, \u0026r);\nnet/nfc/hci/command.c-330-\t\tif (pipe == NFC_HCI_INVALID_PIPE)\n--\nnet/nfc/hci/command.c-336-open_pipe:\nnet/nfc/hci/command.c:337:\tr = nfc_hci_open_pipe(hdev, pipe);\nnet/nfc/hci/command.c-338-\tif (r \u003c 0) {\nnet/nfc/hci/command.c-339-\t\tif (pipe_created)\nnet/nfc/hci/command.c:340:\t\t\tif (nfc_hci_delete_pipe(hdev, pipe) \u003c 0) {\nnet/nfc/hci/command.c-341-\t\t\t\t/* TODO: Cannot clean by deleting pipe...\n--\nnet/nfc/hci/command.c-352-}\nnet/nfc/hci/command.c:353:EXPORT_SYMBOL(nfc_hci_connect_gate);\n--\nnet/nfc/hci/core.c-21-\nnet/nfc/hci/core.c:22:int nfc_hci_result_to_errno(u8 result)\nnet/nfc/hci/core.c-23-{\n--\nnet/nfc/hci/core.c-34-}\nnet/nfc/hci/core.c:35:EXPORT_SYMBOL(nfc_hci_result_to_errno);\nnet/nfc/hci/core.c-36-\nnet/nfc/hci/core.c:37:void nfc_hci_reset_pipes(struct nfc_hci_dev *hdev)\nnet/nfc/hci/core.c-38-{\n--\nnet/nfc/hci/core.c-46-}\nnet/nfc/hci/core.c:47:EXPORT_SYMBOL(nfc_hci_reset_pipes);\nnet/nfc/hci/core.c-48-\nnet/nfc/hci/core.c:49:void nfc_hci_reset_pipes_per_host(struct nfc_hci_dev *hdev, u8 host)\nnet/nfc/hci/core.c-50-{\n--\nnet/nfc/hci/core.c-60-}\nnet/nfc/hci/core.c:61:EXPORT_SYMBOL(nfc_hci_reset_pipes_per_host);\nnet/nfc/hci/core.c-62-\nnet/nfc/hci/core.c:63:static void nfc_hci_msg_tx_work(struct work_struct *work)\nnet/nfc/hci/core.c-64-{\nnet/nfc/hci/core.c:65:\tstruct nfc_hci_dev *hdev = container_of(work, struct nfc_hci_dev,\nnet/nfc/hci/core.c-66-\t\t\t\t\t\tmsg_tx_work);\n--\nnet/nfc/hci/core.c-125-\nnet/nfc/hci/core.c:126:static void nfc_hci_msg_rx_work(struct work_struct *work)\nnet/nfc/hci/core.c-127-{\nnet/nfc/hci/core.c:128:\tstruct nfc_hci_dev *hdev = container_of(work, struct nfc_hci_dev,\nnet/nfc/hci/core.c-129-\t\t\t\t\t\tmsg_rx_work);\n--\nnet/nfc/hci/core.c-143-\nnet/nfc/hci/core.c:144:\t\tnfc_hci_hcp_message_rx(hdev, pipe, type, instruction, skb);\nnet/nfc/hci/core.c-145-\t}\n--\nnet/nfc/hci/core.c-147-\nnet/nfc/hci/core.c:148:static void __nfc_hci_cmd_completion(struct nfc_hci_dev *hdev, int err,\nnet/nfc/hci/core.c-149-\t\t\t\t     struct sk_buff *skb)\n--\nnet/nfc/hci/core.c-164-\nnet/nfc/hci/core.c:165:void nfc_hci_resp_received(struct nfc_hci_dev *hdev, u8 result,\nnet/nfc/hci/core.c-166-\t\t\t   struct sk_buff *skb)\n--\nnet/nfc/hci/core.c-174-\nnet/nfc/hci/core.c:175:\t__nfc_hci_cmd_completion(hdev, nfc_hci_result_to_errno(result), skb);\nnet/nfc/hci/core.c-176-\n--\nnet/nfc/hci/core.c-180-\nnet/nfc/hci/core.c:181:void nfc_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,\nnet/nfc/hci/core.c-182-\t\t\t  struct sk_buff *skb)\n--\nnet/nfc/hci/core.c-249-\nnet/nfc/hci/core.c:250:\t\tnfc_hci_reset_pipes_per_host(hdev, cleared_info-\u003ehost);\nnet/nfc/hci/core.c-251-\t\tbreak;\n--\nnet/nfc/hci/core.c-260-exit:\nnet/nfc/hci/core.c:261:\tnfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_RESPONSE,\nnet/nfc/hci/core.c-262-\t\t\t       status, NULL, 0, NULL, NULL, 0);\n--\nnet/nfc/hci/core.c-266-\nnet/nfc/hci/core.c:267:u32 nfc_hci_sak_to_protocol(u8 sak)\nnet/nfc/hci/core.c-268-{\n--\nnet/nfc/hci/core.c-281-}\nnet/nfc/hci/core.c:282:EXPORT_SYMBOL(nfc_hci_sak_to_protocol);\nnet/nfc/hci/core.c-283-\nnet/nfc/hci/core.c:284:int nfc_hci_target_discovered(struct nfc_hci_dev *hdev, u8 gate)\nnet/nfc/hci/core.c-285-{\n--\nnet/nfc/hci/core.c-299-\tcase NFC_HCI_RF_READER_A_GATE:\nnet/nfc/hci/core.c:300:\t\tr = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c-301-\t\t\t\t      NFC_HCI_RF_READER_A_ATQA, \u0026atqa_skb);\n--\nnet/nfc/hci/core.c-304-\nnet/nfc/hci/core.c:305:\t\tr = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c-306-\t\t\t\t      NFC_HCI_RF_READER_A_SAK, \u0026sak_skb);\n--\nnet/nfc/hci/core.c-315-\t\ttargets-\u003esupported_protocols =\nnet/nfc/hci/core.c:316:\t\t\t\tnfc_hci_sak_to_protocol(sak_skb-\u003edata[0]);\nnet/nfc/hci/core.c-317-\t\tif (targets-\u003esupported_protocols == 0xffffffff) {\n--\nnet/nfc/hci/core.c-324-\nnet/nfc/hci/core.c:325:\t\tr = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c-326-\t\t\t\t      NFC_HCI_RF_READER_A_UID, \u0026uid_skb);\n--\nnet/nfc/hci/core.c-378-}\nnet/nfc/hci/core.c:379:EXPORT_SYMBOL(nfc_hci_target_discovered);\nnet/nfc/hci/core.c-380-\nnet/nfc/hci/core.c:381:void nfc_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe, u8 event,\nnet/nfc/hci/core.c-382-\t\t\t    struct sk_buff *skb)\n--\nnet/nfc/hci/core.c-425-\nnet/nfc/hci/core.c:426:\t\tr = nfc_hci_target_discovered(hdev, gate);\nnet/nfc/hci/core.c-427-\t\tbreak;\n--\nnet/nfc/hci/core.c-438-\tif (r)\nnet/nfc/hci/core.c:439:\t\tnfc_hci_driver_failure(hdev, r);\nnet/nfc/hci/core.c-440-}\nnet/nfc/hci/core.c-441-\nnet/nfc/hci/core.c:442:static void nfc_hci_cmd_timeout(struct timer_list *t)\nnet/nfc/hci/core.c-443-{\nnet/nfc/hci/core.c:444:\tstruct nfc_hci_dev *hdev = timer_container_of(hdev, t, cmd_timer);\nnet/nfc/hci/core.c-445-\n--\nnet/nfc/hci/core.c-448-\nnet/nfc/hci/core.c:449:static int hci_dev_connect_gates(struct nfc_hci_dev *hdev, u8 gate_count,\nnet/nfc/hci/core.c:450:\t\t\t\t const struct nfc_hci_gate *gates)\nnet/nfc/hci/core.c-451-{\n--\nnet/nfc/hci/core.c-453-\twhile (gate_count--) {\nnet/nfc/hci/core.c:454:\t\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\nnet/nfc/hci/core.c-455-\t\t\t\t\t gates-\u003egate, gates-\u003epipe);\n--\nnet/nfc/hci/core.c-463-\nnet/nfc/hci/core.c:464:static int hci_dev_session_init(struct nfc_hci_dev *hdev)\nnet/nfc/hci/core.c-465-{\n--\nnet/nfc/hci/core.c-471-\nnet/nfc/hci/core.c:472:\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\nnet/nfc/hci/core.c-473-\t\t\t\t hdev-\u003einit_data.gates[0].gate,\n--\nnet/nfc/hci/core.c-477-\nnet/nfc/hci/core.c:478:\tr = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,\nnet/nfc/hci/core.c-479-\t\t\t      NFC_HCI_ADMIN_SESSION_IDENTITY, \u0026skb);\n--\nnet/nfc/hci/core.c-493-\nnet/nfc/hci/core.c:494:\t\tr = nfc_hci_disconnect_all_gates(hdev);\nnet/nfc/hci/core.c-495-\t\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c-502-\nnet/nfc/hci/core.c:503:\t\tr = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,\nnet/nfc/hci/core.c-504-\t\t\t\tNFC_HCI_ADMIN_SESSION_IDENTITY,\n--\nnet/nfc/hci/core.c-511-disconnect_all:\nnet/nfc/hci/core.c:512:\tnfc_hci_disconnect_all_gates(hdev);\nnet/nfc/hci/core.c-513-\n--\nnet/nfc/hci/core.c-519-\nnet/nfc/hci/core.c:520:static int hci_dev_version(struct nfc_hci_dev *hdev)\nnet/nfc/hci/core.c-521-{\n--\nnet/nfc/hci/core.c-524-\nnet/nfc/hci/core.c:525:\tr = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,\nnet/nfc/hci/core.c-526-\t\t\t      NFC_HCI_ID_MGMT_VERSION_SW, \u0026skb);\n--\nnet/nfc/hci/core.c-545-\nnet/nfc/hci/core.c:546:\tr = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,\nnet/nfc/hci/core.c-547-\t\t\t      NFC_HCI_ID_MGMT_VERSION_HW, \u0026skb);\n--\nnet/nfc/hci/core.c=579=static int hci_dev_up(struct nfc_dev *nfc_dev)\nnet/nfc/hci/core.c-580-{\nnet/nfc/hci/core.c:581:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-582-\tint r = 0;\n--\nnet/nfc/hci/core.c-597-\nnet/nfc/hci/core.c:598:\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c-599-\t\t\t       NFC_HCI_EVT_END_OPERATION, NULL, 0);\n--\nnet/nfc/hci/core.c=625=static int hci_dev_down(struct nfc_dev *nfc_dev)\nnet/nfc/hci/core.c-626-{\nnet/nfc/hci/core.c:627:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-628-\n--\nnet/nfc/hci/core.c-633-\nnet/nfc/hci/core.c:634:\tnfc_hci_reset_pipes(hdev);\nnet/nfc/hci/core.c-635-\n--\nnet/nfc/hci/core.c=639=static int hci_start_poll(struct nfc_dev *nfc_dev,\n--\nnet/nfc/hci/core.c-641-{\nnet/nfc/hci/core.c:642:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-643-\n--\nnet/nfc/hci/core.c-646-\telse\nnet/nfc/hci/core.c:647:\t\treturn nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c-648-\t\t\t\t\t  NFC_HCI_EVT_READER_REQUESTED,\n--\nnet/nfc/hci/core.c=652=static void hci_stop_poll(struct nfc_dev *nfc_dev)\nnet/nfc/hci/core.c-653-{\nnet/nfc/hci/core.c:654:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-655-\n--\nnet/nfc/hci/core.c-658-\telse\nnet/nfc/hci/core.c:659:\t\tnfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c-660-\t\t\t\t   NFC_HCI_EVT_END_OPERATION, NULL, 0);\n--\nnet/nfc/hci/core.c=663=static int hci_dep_link_up(struct nfc_dev *nfc_dev, struct nfc_target *target,\n--\nnet/nfc/hci/core.c-665-{\nnet/nfc/hci/core.c:666:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-667-\n--\nnet/nfc/hci/core.c=675=static int hci_dep_link_down(struct nfc_dev *nfc_dev)\nnet/nfc/hci/core.c-676-{\nnet/nfc/hci/core.c:677:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-678-\n--\nnet/nfc/hci/core.c=699=static void hci_transceive_cb(void *context, struct sk_buff *skb, int err)\nnet/nfc/hci/core.c-700-{\nnet/nfc/hci/core.c:701:\tstruct nfc_hci_dev *hdev = context;\nnet/nfc/hci/core.c-702-\n--\nnet/nfc/hci/core.c=722=static int hci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,\n--\nnet/nfc/hci/core.c-725-{\nnet/nfc/hci/core.c:726:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-727-\tint r;\n--\nnet/nfc/hci/core.c-746-\nnet/nfc/hci/core.c:747:\t\tr = nfc_hci_send_cmd_async(hdev, target-\u003ehci_reader_gate,\nnet/nfc/hci/core.c-748-\t\t\t\t\t   NFC_HCI_WR_XCHG_DATA, skb-\u003edata,\n--\nnet/nfc/hci/core.c=768=static int hci_tm_send(struct nfc_dev *nfc_dev, struct sk_buff *skb)\nnet/nfc/hci/core.c-769-{\nnet/nfc/hci/core.c:770:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-771-\n--\nnet/nfc/hci/core.c=780=static int hci_check_presence(struct nfc_dev *nfc_dev,\n--\nnet/nfc/hci/core.c-782-{\nnet/nfc/hci/core.c:783:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-784-\n--\nnet/nfc/hci/core.c=791=static int hci_discover_se(struct nfc_dev *nfc_dev)\nnet/nfc/hci/core.c-792-{\nnet/nfc/hci/core.c:793:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-794-\n--\nnet/nfc/hci/core.c=801=static int hci_enable_se(struct nfc_dev *nfc_dev, u32 se_idx)\nnet/nfc/hci/core.c-802-{\nnet/nfc/hci/core.c:803:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-804-\n--\nnet/nfc/hci/core.c=811=static int hci_disable_se(struct nfc_dev *nfc_dev, u32 se_idx)\nnet/nfc/hci/core.c-812-{\nnet/nfc/hci/core.c:813:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-814-\n--\nnet/nfc/hci/core.c=821=static int hci_se_io(struct nfc_dev *nfc_dev, u32 se_idx,\n--\nnet/nfc/hci/core.c-824-{\nnet/nfc/hci/core.c:825:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-826-\n--\nnet/nfc/hci/core.c-833-\nnet/nfc/hci/core.c:834:static void nfc_hci_failure(struct nfc_hci_dev *hdev, int err)\nnet/nfc/hci/core.c-835-{\n--\nnet/nfc/hci/core.c-842-\nnet/nfc/hci/core.c:843:\t__nfc_hci_cmd_completion(hdev, err, NULL);\nnet/nfc/hci/core.c-844-\n--\nnet/nfc/hci/core.c-848-\nnet/nfc/hci/core.c:849:static void nfc_hci_llc_failure(struct nfc_hci_dev *hdev, int err)\nnet/nfc/hci/core.c-850-{\nnet/nfc/hci/core.c:851:\tnfc_hci_failure(hdev, err);\nnet/nfc/hci/core.c-852-}\nnet/nfc/hci/core.c-853-\nnet/nfc/hci/core.c:854:static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb)\nnet/nfc/hci/core.c-855-{\n--\nnet/nfc/hci/core.c-888-\t\tif (hcp_skb == NULL) {\nnet/nfc/hci/core.c:889:\t\t\tnfc_hci_failure(hdev, -ENOMEM);\nnet/nfc/hci/core.c-890-\t\t\treturn;\n--\nnet/nfc/hci/core.c-923-\t\t\t NFC_HCI_HCP_MESSAGE_HEADER_LEN);\nnet/nfc/hci/core.c:924:\t\tnfc_hci_hcp_message_rx(hdev, pipe, type, instruction, hcp_skb);\nnet/nfc/hci/core.c-925-\t} else {\n--\nnet/nfc/hci/core.c=931=static int hci_fw_download(struct nfc_dev *nfc_dev, const char *firmware_name)\nnet/nfc/hci/core.c-932-{\nnet/nfc/hci/core.c:933:\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\nnet/nfc/hci/core.c-934-\n--\nnet/nfc/hci/core.c=941=static const struct nfc_ops hci_nfc_ops = {\n--\nnet/nfc/hci/core.c-959-\nnet/nfc/hci/core.c:960:struct nfc_hci_dev *nfc_hci_allocate_device(const struct nfc_hci_ops *ops,\nnet/nfc/hci/core.c:961:\t\t\t\t\t    struct nfc_hci_init_data *init_data,\nnet/nfc/hci/core.c-962-\t\t\t\t\t    unsigned long quirks,\n--\nnet/nfc/hci/core.c-968-{\nnet/nfc/hci/core.c:969:\tstruct nfc_hci_dev *hdev;\nnet/nfc/hci/core.c-970-\n--\nnet/nfc/hci/core.c-976-\nnet/nfc/hci/core.c:977:\thdev = kzalloc_obj(struct nfc_hci_dev);\nnet/nfc/hci/core.c-978-\tif (hdev == NULL)\n--\nnet/nfc/hci/core.c-981-\thdev-\u003ellc = nfc_llc_allocate(llc_name, hdev, ops-\u003exmit,\nnet/nfc/hci/core.c:982:\t\t\t\t     nfc_hci_recv_from_llc, tx_headroom,\nnet/nfc/hci/core.c:983:\t\t\t\t     tx_tailroom, nfc_hci_llc_failure);\nnet/nfc/hci/core.c-984-\tif (hdev-\u003ellc == NULL) {\n--\nnet/nfc/hci/core.c-1003-\nnet/nfc/hci/core.c:1004:\tnfc_hci_reset_pipes(hdev);\nnet/nfc/hci/core.c-1005-\n--\nnet/nfc/hci/core.c-1009-}\nnet/nfc/hci/core.c:1010:EXPORT_SYMBOL(nfc_hci_allocate_device);\nnet/nfc/hci/core.c-1011-\nnet/nfc/hci/core.c:1012:void nfc_hci_free_device(struct nfc_hci_dev *hdev)\nnet/nfc/hci/core.c-1013-{\n--\nnet/nfc/hci/core.c-1017-}\nnet/nfc/hci/core.c:1018:EXPORT_SYMBOL(nfc_hci_free_device);\nnet/nfc/hci/core.c-1019-\nnet/nfc/hci/core.c:1020:int nfc_hci_register_device(struct nfc_hci_dev *hdev)\nnet/nfc/hci/core.c-1021-{\n--\nnet/nfc/hci/core.c-1025-\nnet/nfc/hci/core.c:1026:\tINIT_WORK(\u0026hdev-\u003emsg_tx_work, nfc_hci_msg_tx_work);\nnet/nfc/hci/core.c-1027-\nnet/nfc/hci/core.c:1028:\ttimer_setup(\u0026hdev-\u003ecmd_timer, nfc_hci_cmd_timeout, 0);\nnet/nfc/hci/core.c-1029-\n--\nnet/nfc/hci/core.c-1031-\nnet/nfc/hci/core.c:1032:\tINIT_WORK(\u0026hdev-\u003emsg_rx_work, nfc_hci_msg_rx_work);\nnet/nfc/hci/core.c-1033-\n--\nnet/nfc/hci/core.c-1037-}\nnet/nfc/hci/core.c:1038:EXPORT_SYMBOL(nfc_hci_register_device);\nnet/nfc/hci/core.c-1039-\nnet/nfc/hci/core.c:1040:void nfc_hci_unregister_device(struct nfc_hci_dev *hdev)\nnet/nfc/hci/core.c-1041-{\n--\nnet/nfc/hci/core.c-1074-}\nnet/nfc/hci/core.c:1075:EXPORT_SYMBOL(nfc_hci_unregister_device);\nnet/nfc/hci/core.c-1076-\nnet/nfc/hci/core.c:1077:void nfc_hci_set_clientdata(struct nfc_hci_dev *hdev, void *clientdata)\nnet/nfc/hci/core.c-1078-{\n--\nnet/nfc/hci/core.c-1080-}\nnet/nfc/hci/core.c:1081:EXPORT_SYMBOL(nfc_hci_set_clientdata);\nnet/nfc/hci/core.c-1082-\nnet/nfc/hci/core.c:1083:void *nfc_hci_get_clientdata(struct nfc_hci_dev *hdev)\nnet/nfc/hci/core.c-1084-{\n--\nnet/nfc/hci/core.c-1086-}\nnet/nfc/hci/core.c:1087:EXPORT_SYMBOL(nfc_hci_get_clientdata);\nnet/nfc/hci/core.c-1088-\nnet/nfc/hci/core.c:1089:void nfc_hci_driver_failure(struct nfc_hci_dev *hdev, int err)\nnet/nfc/hci/core.c-1090-{\nnet/nfc/hci/core.c:1091:\tnfc_hci_failure(hdev, err);\nnet/nfc/hci/core.c-1092-}\n\n"
}

gemini-3.8-flash

null

null

							input: 24965
							output: 35
							thoughts: 130
						

**Debugging a Potential NFC HCI Bug**

Okay, hold on a second. This "syz-cluster: applied patch under review" message has me intrigued. Where did this bug originate? Let's dive in. First, I'll need to check the git history related to this file or function. I'm thinking of searching for commits related to `nfc_hci_create_pipe`. Ideally, I'd fire up `git log -n 5 net/nfc/hci/command.c` to see the most recent changes to that specific file. But, wait... no `git log`? Fine. I can still examine the patch itself and look for clues. Alternatively, I'll check for any git blame annotations which might offer some insights. I'll also consider checking the Kconfig file for NFC HCI to see if there have been recent configurations.

{
  "File": "net/nfc/hci/Kconfig",
  "FirstLine": 1,
  "LineCount": 50
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0-only\n   2:\tconfig NFC_HCI\n   3:\t\tdepends on NFC\n   4:\t\ttristate \"NFC HCI implementation\"\n   5:\t\tdefault n\n   6:\t\thelp\n   7:\t\t  Say Y here if you want to build support for a kernel NFC HCI\n   8:\t\t  implementation. This is mostly needed for devices that only process\n   9:\t\t  HCI frames, like for example the NXP pn544.\n  10:\t\n  11:\tconfig NFC_SHDLC\n  12:\t\tdepends on NFC_HCI\n  13:\t\tselect CRC_CCITT\n  14:\t\tbool \"SHDLC link layer for HCI based NFC drivers\"\n  15:\t\tdefault n\n  16:\t\thelp\n  17:\t\t  Say yes if you use an NFC HCI driver that requires SHDLC link layer.\n  18:\t\t  If unsure, say N here.\n"
}

gemini-3.8-flash

null

null

							input: 25558
							output: 22
							thoughts: 181
						

**My Investigation into NFC HCI**

Okay, so I'm looking into `NFC_HCI`. My initial thought is that it relies on the core `NFC` module, which is obvious. But then the question arises: is `nfc_hci_create_pipe` actually being used? I need to get a clear understanding of the registration and operational flow of an NFC HCI device, especially to trace the execution path of `nfc_hci_create_pipe`.

The next step is crucial: can something like syzkaller be used to create and test an NFC device specifically configured with `NFC_HCI`? If so, then I have a good testing vector.

I'm thinking I'll need to check the drivers. I'll look at `drivers/nfc/virtual_ncidev.c`, `drivers/nfc/nfcsim.c`, and USB NFC devices, to see how these virtual or simulated devices are handled. The key question is whether any of them leverage the `NFC_HCI` layer, or if it's strictly limited to i2c/spi/mei hardware.

Finally, just to be thorough and find everything that uses this particular function, I should do a global search for `nfc_hci_allocate_device` across the entire codebase. That should give me a good handle on where this function is used.

{
  "Expression": "nfc_hci_allocate_device"
}

{
  "Output": "drivers/nfc/microread/microread.c=670=int microread_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\n--\ndrivers/nfc/microread/microread.c-702-\ndrivers/nfc/microread/microread.c:703:\tinfo-\u003ehdev = nfc_hci_allocate_device(\u0026microread_hci_ops, \u0026init_data,\ndrivers/nfc/microread/microread.c-704-\t\t\t\t\t     quirks, protocols, llc_name,\n--\ndrivers/nfc/pn544/pn544.c=903=int pn544_hci_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\n--\ndrivers/nfc/pn544/pn544.c-941-\ndrivers/nfc/pn544/pn544.c:942:\tinfo-\u003ehdev = nfc_hci_allocate_device(\u0026pn544_hci_ops, \u0026init_data, 0,\ndrivers/nfc/pn544/pn544.c-943-\t\t\t\t\t     protocols, llc_name,\n--\ndrivers/nfc/st21nfca/core.c=937=int st21nfca_hci_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\n--\ndrivers/nfc/st21nfca/core.c-987-\tinfo-\u003ehdev =\ndrivers/nfc/st21nfca/core.c:988:\t    nfc_hci_allocate_device(\u0026st21nfca_hci_ops, \u0026init_data, quirks,\ndrivers/nfc/st21nfca/core.c-989-\t\t\t\t    protocols, llc_name,\n--\ninclude/net/nfc/hci.h=99=struct nfc_hci_dev {\n--\ninclude/net/nfc/hci.h-153-/* hci device allocation */\ninclude/net/nfc/hci.h:154:struct nfc_hci_dev *nfc_hci_allocate_device(const struct nfc_hci_ops *ops,\ninclude/net/nfc/hci.h-155-\t\t\t\t\t    struct nfc_hci_init_data *init_data,\n--\nnet/nfc/hci/core.c=941=static const struct nfc_ops hci_nfc_ops = {\n--\nnet/nfc/hci/core.c-959-\nnet/nfc/hci/core.c:960:struct nfc_hci_dev *nfc_hci_allocate_device(const struct nfc_hci_ops *ops,\nnet/nfc/hci/core.c-961-\t\t\t\t\t    struct nfc_hci_init_data *init_data,\n--\nnet/nfc/hci/core.c-1009-}\nnet/nfc/hci/core.c:1010:EXPORT_SYMBOL(nfc_hci_allocate_device);\nnet/nfc/hci/core.c-1011-\n"
}

gemini-3.8-flash

null

null

							input: 26837
							output: 38
							thoughts: 794
						

**Analyzing a Kernel NFC HCI Bug Fix**

Okay, so I see this patch related to NFC HCI, specifically fixing a potential vulnerability. My initial thought is to figure out which devices are even affected by this. The code mentions `microread`, `pn544`, and `st21nfca` calling `nfc_hci_allocate_device`. My first line of inquiry is always to understand the hardware interaction, so I check their bus usage: `i2c` and `mei` for `microread` and `pn544`, and just `i2c` for `st21nfca`.

Then I start thinking about these buses and virtual devices. Does i2c or mei have virtual or emulated devices? I immediately remember `/dev/i2c-*` and sysfs! Can a user-space process create an I2C device via `/sys/bus/i2c/devices/i2c-X/new_device`? Yes, that's possible! This makes me wonder if syzkaller is leveraging that ability to fuzz I2C devices.

Bingo! Does syzkaller have an I2C pseudo-device or i2c client instantiation? Even better, does syzkaller fuzz NFC HCI itself? That's what I want to know! I look at the author and commit information. Ah, it's `syz-cluster <triage@syzkaller.com>`. This tells me that this is likely a patch that was identified and tested by syzkaller. This confirms my suspicion that we're dealing with a bug found through fuzzing.

Now, what crash did this fix? I need to understand the root cause of the bug. I go back to the patch itself. I see a check added for `skb->len < sizeof(*resp)` and `pipe >= NFC_HCI_MAX_PIPES`. Before the fix, the code directly accessed `resp->pipe` without any bounds checking! This looks like a classic out-of-bounds read vulnerability.

If the skb is too small, reading `resp->pipe` could lead to an out-of-bounds read. Or if `pipe` is an invalid number, the code would be in an undefined state. I then need to verify what `nfc_hci_connect_gate` does with this `pipe`, to understand the consequences of the potential out-of-bounds `pipe` value. I need to review the code in `net/nfc/hci/command.c`, lines 306-355, to fully understand the vulnerability.

{
  "File": "net/nfc/hci/command.c",
  "FirstLine": 306,
  "LineCount": 50
}

{
  "Contents": " 306:\tint nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,\n 307:\t\t\t\t u8 pipe)\n 308:\t{\n 309:\t\tbool pipe_created = false;\n 310:\t\tint r;\n 311:\t\n 312:\t\tif (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)\n 313:\t\t\treturn 0;\n 314:\t\n 315:\t\tif (hdev-\u003egate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)\n 316:\t\t\treturn -EADDRINUSE;\n 317:\t\n 318:\t\tif (pipe != NFC_HCI_INVALID_PIPE)\n 319:\t\t\tgoto open_pipe;\n 320:\t\n 321:\t\tswitch (dest_gate) {\n 322:\t\tcase NFC_HCI_LINK_MGMT_GATE:\n 323:\t\t\tpipe = NFC_HCI_LINK_MGMT_PIPE;\n 324:\t\t\tbreak;\n 325:\t\tcase NFC_HCI_ADMIN_GATE:\n 326:\t\t\tpipe = NFC_HCI_ADMIN_PIPE;\n 327:\t\t\tbreak;\n 328:\t\tdefault:\n 329:\t\t\tpipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, \u0026r);\n 330:\t\t\tif (pipe == NFC_HCI_INVALID_PIPE)\n 331:\t\t\t\treturn r;\n 332:\t\t\tpipe_created = true;\n 333:\t\t\tbreak;\n 334:\t\t}\n 335:\t\n 336:\topen_pipe:\n 337:\t\tr = nfc_hci_open_pipe(hdev, pipe);\n 338:\t\tif (r \u003c 0) {\n 339:\t\t\tif (pipe_created)\n 340:\t\t\t\tif (nfc_hci_delete_pipe(hdev, pipe) \u003c 0) {\n 341:\t\t\t\t\t/* TODO: Cannot clean by deleting pipe...\n 342:\t\t\t\t\t * -\u003e inconsistent state */\n 343:\t\t\t\t}\n 344:\t\t\treturn r;\n 345:\t\t}\n 346:\t\n 347:\t\thdev-\u003epipes[pipe].gate = dest_gate;\n 348:\t\thdev-\u003epipes[pipe].dest_host = dest_host;\n 349:\t\thdev-\u003egate2pipe[dest_gate] = pipe;\n 350:\t\n 351:\t\treturn 0;\n 352:\t}\n 353:\tEXPORT_SYMBOL(nfc_hci_connect_gate);\n"
}

gemini-3.8-flash

null

null

							input: 28928
							output: 37
							thoughts: 750
						

**Analyzing Potential Out-of-Bounds Access in NFC HCI Code**

Okay, let's break this down. Line 347, specifically `hdev->pipes[pipe].gate = dest_gate;`, is what's catching my eye. `hdev->pipes` is an array with a size of `NFC_HCI_MAX_PIPES`. If `pipe` is greater than or equal to `NFC_HCI_MAX_PIPES`, that's an out-of-bounds write, plain and simple. Similarly, a potential out-of-bounds read exists if `skb->len` is smaller than `sizeof(*resp)`, accessing `resp->pipe`.

Now, the crucial question is reachability. Can syzkaller actually *get* to `nfc_hci_connect_gate`? It’s a core fuzzing principle that we only focus on reachable code. Let's refer back to the triage philosophy. Section 1 explicitly states reachability is the primary gate: if code is structurally unreachable, it's not worth fuzzing.

Section 2 provides specific negative criteria. We're looking for “Structurally unreachable hardware” or “Unreachable execution paths”. This *isn't* vendor-specific PCIe or driver teardown callbacks, so we're okay there.

On the positive side, Section 3 tells us to consider code within core subsystems, refactorings, assertions, and *reachable drivers and protocols*, particularly those accessible via virtual buses, USB, netlink, etc.

So, is NFC HCI reachable? That's the key. Let's classify it. We know it’s `net/nfc/hci`, so let's check for any connections: Does it use networking, netlink, sockets, virtual buses, or virtual devices? The fact that it's in the networking area certainly raises a flag. We need to determine if there's any pathway that links to it. What about `virtual_ncidev` or `nfcsim`? I'll need to read `drivers/nfc/virtual_ncidev.c` to see if that device represents a reachable path to this code. It could be that those devices offer a virtual environment to interact with the code, or perhaps even a device that can trigger those values.

{
  "File": "drivers/nfc/virtual_ncidev.c",
  "FirstLine": 1,
  "LineCount": 80
}

{
  "Contents": "   1:\t// SPDX-License-Identifier: GPL-2.0-or-later\n   2:\t/*\n   3:\t * Virtual NCI device simulation driver\n   4:\t *\n   5:\t * Copyright (C) 2020 Samsung Electronics\n   6:\t * Bongsu Jeon \u003cbongsu.jeon@samsung.com\u003e\n   7:\t */\n   8:\t\n   9:\t#include \u003clinux/kernel.h\u003e\n  10:\t#include \u003clinux/module.h\u003e\n  11:\t#include \u003clinux/miscdevice.h\u003e\n  12:\t#include \u003clinux/mutex.h\u003e\n  13:\t#include \u003clinux/wait.h\u003e\n  14:\t#include \u003cnet/nfc/nci_core.h\u003e\n  15:\t\n  16:\t#define IOCTL_GET_NCIDEV_IDX    0\n  17:\t#define VIRTUAL_NFC_PROTOCOLS\t(NFC_PROTO_JEWEL_MASK | \\\n  18:\t\t\t\t\t NFC_PROTO_MIFARE_MASK | \\\n  19:\t\t\t\t\t NFC_PROTO_FELICA_MASK | \\\n  20:\t\t\t\t\t NFC_PROTO_ISO14443_MASK | \\\n  21:\t\t\t\t\t NFC_PROTO_ISO14443_B_MASK | \\\n  22:\t\t\t\t\t NFC_PROTO_ISO15693_MASK)\n  23:\t\n  24:\tstruct virtual_nci_dev {\n  25:\t\tstruct nci_dev *ndev;\n  26:\t\tstruct mutex mtx;\n  27:\t\tstruct sk_buff *send_buff;\n  28:\t\tstruct wait_queue_head wq;\n  29:\t\tbool running;\n  30:\t};\n  31:\t\n  32:\tstatic int virtual_nci_open(struct nci_dev *ndev)\n  33:\t{\n  34:\t\tstruct virtual_nci_dev *vdev = nci_get_drvdata(ndev);\n  35:\t\n  36:\t\tvdev-\u003erunning = true;\n  37:\t\treturn 0;\n  38:\t}\n  39:\t\n  40:\tstatic int virtual_nci_close(struct nci_dev *ndev)\n  41:\t{\n  42:\t\tstruct virtual_nci_dev *vdev = nci_get_drvdata(ndev);\n  43:\t\n  44:\t\tmutex_lock(\u0026vdev-\u003emtx);\n  45:\t\tkfree_skb(vdev-\u003esend_buff);\n  46:\t\tvdev-\u003esend_buff = NULL;\n  47:\t\tvdev-\u003erunning = false;\n  48:\t\tmutex_unlock(\u0026vdev-\u003emtx);\n  49:\t\n  50:\t\treturn 0;\n  51:\t}\n  52:\t\n  53:\tstatic int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb)\n  54:\t{\n  55:\t\tstruct virtual_nci_dev *vdev = nci_get_drvdata(ndev);\n  56:\t\n  57:\t\tmutex_lock(\u0026vdev-\u003emtx);\n  58:\t\tif (vdev-\u003esend_buff || !vdev-\u003erunning) {\n  59:\t\t\tmutex_unlock(\u0026vdev-\u003emtx);\n  60:\t\t\tkfree_skb(skb);\n  61:\t\t\treturn -1;\n  62:\t\t}\n  63:\t\tvdev-\u003esend_buff = skb_copy(skb, GFP_KERNEL);\n  64:\t\tif (!vdev-\u003esend_buff) {\n  65:\t\t\tmutex_unlock(\u0026vdev-\u003emtx);\n  66:\t\t\tkfree_skb(skb);\n  67:\t\t\treturn -1;\n  68:\t\t}\n  69:\t\tmutex_unlock(\u0026vdev-\u003emtx);\n  70:\t\twake_up_interruptible(\u0026vdev-\u003ewq);\n  71:\t\tconsume_skb(skb);\n  72:\t\n  73:\t\treturn 0;\n  74:\t}\n  75:\t\n  76:\tstatic const struct nci_ops virtual_nci_ops = {\n  77:\t\t.open = virtual_nci_open,\n  78:\t\t.close = virtual_nci_close,\n  79:\t\t.send = virtual_nci_send\n  80:\t};\n"
}

gemini-3.8-flash

null

null

							input: 31330
							output: 32
							thoughts: 106
						

**NCI Confusion Resolved**

Okay, so I was initially thrown for a loop because I saw `virtual_nci_dev` and immediately thought "HCI," but that's not right. This is definitely an NCI thing. But then I paused. Does the NCI stack *use* anything from the `net/nfc/hci` directory? It's been a while since I've been deep in the weeds with the NFC stack. Time for a quick check. Ah, good, the previous `grep` showed me something: `net/nfc/nci/hci.c`! Okay, that's a key file to focus on. Now, a more targeted question, does `net/nfc/nci/hci.c` actually *call* anything from `net/nfc/hci/command.c`? That would cement the connection. Let's dig into `net/nfc/nci/hci.c` and find out.

no matches

{
  "Expression": "nfc_hci_",
  "PathPrefix": "net/nfc/nci"
}

{
  "error": "no matches"
}

gemini-3.8-flash

null

null

							input: 31692
							output: 36
							thoughts: 56
						

Okay, let's break this down.

**Investigating NFC HCI Driver Usage**

Right, so I'm looking at `net/nfc/nci/hci.c`, and it's using the `nci_hci_*` functions, not the `nfc_hci_*` ones. That's good to know, that it follows the `NCI` standard. Now, the next logical step is to see if any other parts of the system are *actually* using those `nfc_hci_*` functions, to check if they're still relevant, or if they're being kept around for legacy support. My instinct is that they might be deprecated, given the shift to NCI, but I need to confirm that. So, let's dive into `nfcsim.c`. That should be a good place to start, given the name. Let's see if that file sheds some light on what's going on with the `nfc_hci_*` functions.

{
  "File": "drivers/nfc/nfcsim.c",
  "FirstLine": 1,
  "LineCount": 60
}

{
  "Contents": "   1:\t// SPDX-License-Identifier: GPL-2.0-only\n   2:\t/*\n   3:\t * NFC hardware simulation driver\n   4:\t * Copyright (c) 2013, Intel Corporation.\n   5:\t */\n   6:\t\n   7:\t#include \u003clinux/device.h\u003e\n   8:\t#include \u003clinux/kernel.h\u003e\n   9:\t#include \u003clinux/module.h\u003e\n  10:\t#include \u003clinux/ctype.h\u003e\n  11:\t#include \u003clinux/debugfs.h\u003e\n  12:\t#include \u003clinux/nfc.h\u003e\n  13:\t#include \u003cnet/nfc/nfc.h\u003e\n  14:\t#include \u003cnet/nfc/digital.h\u003e\n  15:\t\n  16:\t#define NFCSIM_ERR(d, fmt, args...) nfc_err(\u0026d-\u003enfc_digital_dev-\u003enfc_dev-\u003edev, \\\n  17:\t\t\t\t\t\t    \"%s: \" fmt, __func__, ## args)\n  18:\t\n  19:\t#define NFCSIM_DBG(d, fmt, args...) dev_dbg(\u0026d-\u003enfc_digital_dev-\u003enfc_dev-\u003edev, \\\n  20:\t\t\t\t\t\t    \"%s: \" fmt, __func__, ## args)\n  21:\t\n  22:\t#define NFCSIM_VERSION \"0.2\"\n  23:\t\n  24:\t#define NFCSIM_MODE_NONE\t0\n  25:\t#define NFCSIM_MODE_INITIATOR\t1\n  26:\t#define NFCSIM_MODE_TARGET\t2\n  27:\t\n  28:\t#define NFCSIM_CAPABILITIES (NFC_DIGITAL_DRV_CAPS_IN_CRC   | \\\n  29:\t\t\t\t     NFC_DIGITAL_DRV_CAPS_TG_CRC)\n  30:\t\n  31:\tstruct nfcsim {\n  32:\t\tstruct nfc_digital_dev *nfc_digital_dev;\n  33:\t\n  34:\t\tstruct work_struct recv_work;\n  35:\t\tstruct delayed_work send_work;\n  36:\t\n  37:\t\tstruct nfcsim_link *link_in;\n  38:\t\tstruct nfcsim_link *link_out;\n  39:\t\n  40:\t\tbool up;\n  41:\t\tu8 mode;\n  42:\t\tu8 rf_tech;\n  43:\t\n  44:\t\tu16 recv_timeout;\n  45:\t\n  46:\t\tnfc_digital_cmd_complete_t cb;\n  47:\t\tvoid *arg;\n  48:\t\n  49:\t\tu8 dropframe;\n  50:\t};\n  51:\t\n  52:\tstruct nfcsim_link {\n  53:\t\tstruct mutex lock;\n  54:\t\n  55:\t\tu8 rf_tech;\n  56:\t\tu8 mode;\n  57:\t\n  58:\t\tu8 shutdown;\n  59:\t\n  60:\t\tstruct sk_buff *skb;\n"
}

gemini-3.8-flash

null

null

							input: 32798
							output: 24
							thoughts: 1028
						

**Navigating the NFC Fuzzing Landscape**

Okay, so I'm thinking about how to approach fuzzing `nfcsim` with `nfc_digital_dev`.  I'm exploring alternative buses beyond that, like I2C, dummy buses, or MEI. The thought occurs to me to check if QEMU can instantiate I2C devices, which seems like a promising avenue, and luckily Linux offers `i2c-dummy`, `i2c-dev`, and QEMU has i2c buses like `smbus`, `i801`, and `piix4`. Now, the next logical step is to see if syzkaller is helpful here, specifically looking for any existing I2C support within it. My initial search would be for either `syz_i2c` or a `sysfs`  `new_device` call in syzkaller.

Hold on, I remember a critical instruction regarding using our tools with syzkaller. We can't use these to search syzkaller syzlang descriptions or expressions containing `long syz_` without using the correct tools. I need to make sure we're using the right tools, and in our tool declarations, I can see the list: `grepper`, `read-file`, `codesearch-dir-index`, and `set-results`. Looks like we are missing the required `read-syz-spec` and `syz-grepper` tools!

Okay, let's recalibrate. Let's remember the priority: we can only find bugs in code that's executable in standard virtualized environments. Unreachable code is a no-go. I have to apply the filters.

I'm making sure I'm not wasting time on non-executable changes like documentation, comments, user-space, purely decorative logging, or build system/Kconfig changes that don't alter the compiled C logic. I'm also avoiding structurally unreachable hardware (vendor-specific PCIe switches, etc. requiring physical components not emulated in standard QEMU) and unreachable execution paths like driver teardown callbacks.

Now, positive criteria for fuzzing. Anything touching *reachable* executable code is fair game. This includes core subsystems, refactorings, runtime assertions, and reachable drivers/protocols. Is `net/nfc/hci/command.c` in `net/` (which sounds like it's core networking)? Core subsystems are definitely something to fuzz. NFC HCI is under `net/nfc/hci/`, but is it a driver or core networking? I need to figure out what drivers use NFC HCI. Let's check for drivers beyond microread, pn544, st21nfca. Now, let's search for  `include <net/nfc/hci.h>` or `include "hci.h"` in the kernel to find related drivers.

{
  "Expression": "\u003cnet/nfc/hci\\.h\u003e"
}

{
  "Output": "drivers/nfc/mei_phy.h-5-#include \u003clinux/mei_cl_bus.h\u003e\ndrivers/nfc/mei_phy.h:6:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/mei_phy.h-7-#include \u003clinux/uuid.h\u003e\n--\ndrivers/nfc/microread/i2c.c-16-#include \u003clinux/nfc.h\u003e\ndrivers/nfc/microread/i2c.c:17:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/microread/i2c.c-18-#include \u003cnet/nfc/llc.h\u003e\n--\ndrivers/nfc/microread/microread.c-16-#include \u003cnet/nfc/nfc.h\u003e\ndrivers/nfc/microread/microread.c:17:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/microread/microread.c-18-\n--\ndrivers/nfc/microread/microread.h-8-\ndrivers/nfc/microread/microread.h:9:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/microread/microread.h-10-\n--\ndrivers/nfc/pn544/i2c.c-21-\ndrivers/nfc/pn544/i2c.c:22:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/pn544/i2c.c-23-#include \u003cnet/nfc/llc.h\u003e\n--\ndrivers/nfc/pn544/mei.c-9-#include \u003clinux/nfc.h\u003e\ndrivers/nfc/pn544/mei.c:10:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/pn544/mei.c-11-#include \u003cnet/nfc/llc.h\u003e\n--\ndrivers/nfc/pn544/pn544.c-14-#include \u003clinux/nfc.h\u003e\ndrivers/nfc/pn544/pn544.c:15:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/pn544/pn544.c-16-\n--\ndrivers/nfc/pn544/pn544.h-8-\ndrivers/nfc/pn544/pn544.h:9:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/pn544/pn544.h-10-\n--\ndrivers/nfc/st21nfca/core.c-9-#include \u003clinux/nfc.h\u003e\ndrivers/nfc/st21nfca/core.c:10:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/st21nfca/core.c-11-\n--\ndrivers/nfc/st21nfca/dep.c-5-\ndrivers/nfc/st21nfca/dep.c:6:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/st21nfca/dep.c-7-\n--\ndrivers/nfc/st21nfca/i2c.c-19-\ndrivers/nfc/st21nfca/i2c.c:20:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/st21nfca/i2c.c-21-#include \u003cnet/nfc/llc.h\u003e\n--\ndrivers/nfc/st21nfca/se.c-5-\ndrivers/nfc/st21nfca/se.c:6:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/st21nfca/se.c-7-\n--\ndrivers/nfc/st21nfca/st21nfca.h-8-\ndrivers/nfc/st21nfca/st21nfca.h:9:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/st21nfca/st21nfca.h-10-#include \u003clinux/skbuff.h\u003e\n--\ndrivers/nfc/st21nfca/vendor_cmds.c-10-#include \u003clinux/nfc.h\u003e\ndrivers/nfc/st21nfca/vendor_cmds.c:11:#include \u003cnet/nfc/hci.h\u003e\ndrivers/nfc/st21nfca/vendor_cmds.c-12-#include \u003cnet/nfc/llc.h\u003e\n--\ninclude/net/nfc/llc.h-10-\ninclude/net/nfc/llc.h:11:#include \u003cnet/nfc/hci.h\u003e\ninclude/net/nfc/llc.h-12-#include \u003clinux/skbuff.h\u003e\n--\nnet/nfc/hci/command.c-12-\nnet/nfc/hci/command.c:13:#include \u003cnet/nfc/hci.h\u003e\nnet/nfc/hci/command.c-14-\n--\nnet/nfc/hci/core.c-13-#include \u003cnet/nfc/nfc.h\u003e\nnet/nfc/hci/core.c:14:#include \u003cnet/nfc/hci.h\u003e\nnet/nfc/hci/core.c-15-#include \u003cnet/nfc/llc.h\u003e\n--\nnet/nfc/hci/hci.h-8-\nnet/nfc/hci/hci.h:9:#include \u003cnet/nfc/hci.h\u003e\nnet/nfc/hci/hci.h-10-\n--\nnet/nfc/hci/hcp.c-11-\nnet/nfc/hci/hcp.c:12:#include \u003cnet/nfc/hci.h\u003e\nnet/nfc/hci/hcp.c-13-\n--\nnet/nfc/hci/llc.h-10-\nnet/nfc/hci/llc.h:11:#include \u003cnet/nfc/hci.h\u003e\nnet/nfc/hci/llc.h-12-#include \u003cnet/nfc/llc.h\u003e\n"
}

gemini-3.8-flash

null

null

							input: 35990
							output: 28
							thoughts: 178
						

**My Initial Thoughts on Emulating NFC Devices**

Okay, so I'm looking at these NFC chip drivers – microread, pn544, and st21nfca. The obvious question is whether I can even get any of these to work within QEMU. That's the first hurdle. Then, I need to figure out if I can emulate something like the Intel Management Engine Interface (MEI) or even I2C, which is likely how these NFC chips are communicating. 

Alright, let's dive into the code. I need to understand how these drivers interact with the I2C bus. I should examine `drivers/nfc/microread/i2c.c`, `drivers/nfc/pn544/i2c.c`, and `drivers/nfc/st21nfca/i2c.c`. I need a clear understanding of the I2C device probing process.

Aha, now the interesting part: Can I, from userspace, effectively create an I2C device? The `/sys/bus/i2c/devices/i2c-X/new_device` path seems like the right place to investigate. I need to understand how the I2C core functions, so I'll check `drivers/i2c/i2c-core-base.c`. This should give me some solid leads.

{
  "Expression": "new_device",
  "PathPrefix": "drivers/i2c"
}

{
  "Output": "drivers/i2c/i2c-core-acpi.c=522=struct notifier_block i2c_acpi_notifier = {\n--\ndrivers/i2c/i2c-core-acpi.c-526-/**\ndrivers/i2c/i2c-core-acpi.c:527: * i2c_acpi_new_device_by_fwnode - Create i2c-client for the Nth I2cSerialBus resource\ndrivers/i2c/i2c-core-acpi.c-528- * @fwnode:  fwnode with the ACPI resources to get the client from\n--\ndrivers/i2c/i2c-core-acpi.c-543- */\ndrivers/i2c/i2c-core-acpi.c:544:struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,\ndrivers/i2c/i2c-core-acpi.c-545-\t\t\t\t\t\t int index,\n--\ndrivers/i2c/i2c-core-acpi.c-578-}\ndrivers/i2c/i2c-core-acpi.c:579:EXPORT_SYMBOL_GPL(i2c_acpi_new_device_by_fwnode);\ndrivers/i2c/i2c-core-acpi.c-580-\n--\ndrivers/i2c/i2c-core-base.c=1264=static ssize_t\ndrivers/i2c/i2c-core-base.c:1265:new_device_store(struct device *dev, struct device_attribute *attr,\ndrivers/i2c/i2c-core-base.c-1266-\t\t const char *buf, size_t count)\n--\ndrivers/i2c/i2c-core-base.c-1277-\tif (!blank) {\ndrivers/i2c/i2c-core-base.c:1278:\t\tdev_err(dev, \"%s: Missing parameters\\n\", \"new_device\");\ndrivers/i2c/i2c-core-base.c-1279-\t\treturn -EINVAL;\n--\ndrivers/i2c/i2c-core-base.c-1281-\tif (blank - buf \u003e I2C_NAME_SIZE - 1) {\ndrivers/i2c/i2c-core-base.c:1282:\t\tdev_err(dev, \"%s: Invalid device name\\n\", \"new_device\");\ndrivers/i2c/i2c-core-base.c-1283-\t\treturn -EINVAL;\n--\ndrivers/i2c/i2c-core-base.c-1289-\tif (res \u003c 1) {\ndrivers/i2c/i2c-core-base.c:1290:\t\tdev_err(dev, \"%s: Can't parse I2C address\\n\", \"new_device\");\ndrivers/i2c/i2c-core-base.c-1291-\t\treturn -EINVAL;\n--\ndrivers/i2c/i2c-core-base.c-1293-\tif (res \u003e 1  \u0026\u0026 end != '\\n') {\ndrivers/i2c/i2c-core-base.c:1294:\t\tdev_err(dev, \"%s: Extra parameters\\n\", \"new_device\");\ndrivers/i2c/i2c-core-base.c-1295-\t\treturn -EINVAL;\n--\ndrivers/i2c/i2c-core-base.c-1315-\tmutex_unlock(\u0026adap-\u003euserspace_clients_lock);\ndrivers/i2c/i2c-core-base.c:1316:\tdev_info(dev, \"%s: Instantiated device %s at 0x%02hx\\n\", \"new_device\",\ndrivers/i2c/i2c-core-base.c-1317-\t\t info.type, info.addr);\n--\ndrivers/i2c/i2c-core-base.c-1320-}\ndrivers/i2c/i2c-core-base.c:1321:static DEVICE_ATTR_WO(new_device);\ndrivers/i2c/i2c-core-base.c-1322-\n--\ndrivers/i2c/i2c-core-base.c-1325- * they got it wrong. This interface can only be used to delete devices\ndrivers/i2c/i2c-core-base.c:1326: * instantiated by i2c_sysfs_new_device above. This guarantees that we\ndrivers/i2c/i2c-core-base.c-1327- * don't delete devices to which some kernel code still has references.\n--\ndrivers/i2c/i2c-core-base.c=1379=static struct attribute *i2c_adapter_attrs[] = {\ndrivers/i2c/i2c-core-base.c-1380-\t\u0026dev_attr_name.attr,\ndrivers/i2c/i2c-core-base.c:1381:\t\u0026dev_attr_new_device.attr,\ndrivers/i2c/i2c-core-base.c-1382-\t\u0026dev_attr_delete_device.attr,\n--\ndrivers/i2c/i2c-core-base.c=1804=void i2c_del_adapter(struct i2c_adapter *adap)\n--\ndrivers/i2c/i2c-core-base.c-1822-\t */\ndrivers/i2c/i2c-core-base.c:1823:\tdevice_remove_file(\u0026adap-\u003edev, \u0026dev_attr_new_device);\ndrivers/i2c/i2c-core-base.c-1824-\n"
}

gemini-3.8-flash

null

null

							input: 37984
							output: 41
							thoughts: 85
						

**My Initial Thoughts on I2C Device Instantiation**

Okay, so this `new_device` entry in sysfs is intriguing. It seems like I can use it to instantiate *any* I2C device – a PN544, a Microread, an ST21NFCA... the possibilities are vast. This opens up a lot of flexibility, but I need to understand the implications better.

First things first, let's step back and consider the probing process. I'm going to quickly check what actually *happens* when I try to probe one of those specific drivers, say `pn544_i2c` or `microread`. Understanding the probe sequence will give me a critical handle.

Specifically, I'm going to zero in on `drivers/nfc/microread/i2c.c`. That seems like the right place to begin dissecting how a Microread device over I2C is handled. That file should contain the key logic for initialization and communication. Once I've got a handle on the probe process and the relevant driver files, I'll be able to see the implications of this `new_device` feature clearly.

{
  "File": "drivers/nfc/microread/i2c.c",
  "FirstLine": 230,
  "LineCount": 50
}

{
  "Contents": " 230:\t\t.disable = microread_i2c_disable,\n 231:\t};\n 232:\t\n 233:\tstatic int microread_i2c_probe(struct i2c_client *client)\n 234:\t{\n 235:\t\tstruct microread_i2c_phy *phy;\n 236:\t\tint r;\n 237:\t\n 238:\t\tphy = devm_kzalloc(\u0026client-\u003edev, sizeof(struct microread_i2c_phy),\n 239:\t\t\t\t   GFP_KERNEL);\n 240:\t\tif (!phy)\n 241:\t\t\treturn -ENOMEM;\n 242:\t\n 243:\t\ti2c_set_clientdata(client, phy);\n 244:\t\tphy-\u003ei2c_dev = client;\n 245:\t\n 246:\t\tr = request_threaded_irq(client-\u003eirq, NULL, microread_i2c_irq_thread_fn,\n 247:\t\t\t\t\t IRQF_TRIGGER_RISING | IRQF_ONESHOT,\n 248:\t\t\t\t\t MICROREAD_I2C_DRIVER_NAME, phy);\n 249:\t\tif (r) {\n 250:\t\t\tnfc_err(\u0026client-\u003edev, \"Unable to register IRQ handler\\n\");\n 251:\t\t\treturn r;\n 252:\t\t}\n 253:\t\n 254:\t\tr = microread_probe(phy, \u0026i2c_phy_ops, LLC_SHDLC_NAME,\n 255:\t\t\t\t    MICROREAD_I2C_FRAME_HEADROOM,\n 256:\t\t\t\t    MICROREAD_I2C_FRAME_TAILROOM,\n 257:\t\t\t\t    MICROREAD_I2C_LLC_MAX_PAYLOAD, \u0026phy-\u003ehdev);\n 258:\t\tif (r \u003c 0)\n 259:\t\t\tgoto err_irq;\n 260:\t\n 261:\t\treturn 0;\n 262:\t\n 263:\terr_irq:\n 264:\t\tfree_irq(client-\u003eirq, phy);\n 265:\t\n 266:\t\treturn r;\n 267:\t}\n 268:\t\n 269:\tstatic void microread_i2c_remove(struct i2c_client *client)\n 270:\t{\n 271:\t\tstruct microread_i2c_phy *phy = i2c_get_clientdata(client);\n 272:\t\n 273:\t\tmicroread_remove(phy-\u003ehdev);\n 274:\t\n 275:\t\tfree_irq(client-\u003eirq, phy);\n 276:\t}\n 277:\t\n 278:\tstatic const struct i2c_device_id microread_i2c_id[] = {\n 279:\t\t{ .name = MICROREAD_I2C_DRIVER_NAME },\n"
}

gemini-3.8-flash

null

null

							input: 39134
							output: 43
							thoughts: 22
						

Here's my take on the thought process, as if it were my own:

**Investigating NFC Driver Implementation**

Okay, so I'm digging into this NFC driver situation, and I need to get a really good handle on how the PN544 is being handled. I've already been focusing on the `drivers/nfc/pn544/` directory, and I've got a decent grasp of the overall architecture. Now, I should make sure I don't miss anything. *Definitely* need to check `drivers/nfc/pn544/i2c.c` as well. I need to understand how the I2C communication is set up. Knowing how data is physically transferred is vital to really understand the bigger picture. I need to be sure the I2C layer isn't causing any issues, so I'll review how it handles the I2C transactions. Time to get my hands dirty.

{
  "File": "drivers/nfc/pn544/i2c.c",
  "FirstLine": 860,
  "LineCount": 60
}

{
  "Contents": " 860:\t\t{ \"enable-gpios\", \u0026enable_gpios, 1 },\n 861:\t\t{ \"firmware-gpios\", \u0026firmware_gpios, 1 },\n 862:\t\t{ },\n 863:\t};\n 864:\t\n 865:\tstatic int pn544_hci_i2c_probe(struct i2c_client *client)\n 866:\t{\n 867:\t\tstruct device *dev = \u0026client-\u003edev;\n 868:\t\tstruct pn544_i2c_phy *phy;\n 869:\t\tint r = 0;\n 870:\t\n 871:\t\tif (!i2c_check_functionality(client-\u003eadapter, I2C_FUNC_I2C)) {\n 872:\t\t\tnfc_err(\u0026client-\u003edev, \"Need I2C_FUNC_I2C\\n\");\n 873:\t\t\treturn -ENODEV;\n 874:\t\t}\n 875:\t\n 876:\t\tphy = devm_kzalloc(\u0026client-\u003edev, sizeof(struct pn544_i2c_phy),\n 877:\t\t\t\t   GFP_KERNEL);\n 878:\t\tif (!phy)\n 879:\t\t\treturn -ENOMEM;\n 880:\t\n 881:\t\tINIT_WORK(\u0026phy-\u003efw_work, pn544_hci_i2c_fw_work);\n 882:\t\tphy-\u003efw_work_state = FW_WORK_STATE_IDLE;\n 883:\t\n 884:\t\tphy-\u003ei2c_dev = client;\n 885:\t\ti2c_set_clientdata(client, phy);\n 886:\t\n 887:\t\tr = devm_acpi_dev_add_driver_gpios(dev, acpi_pn544_gpios);\n 888:\t\tif (r)\n 889:\t\t\tdev_dbg(dev, \"Unable to add GPIO mapping table\\n\");\n 890:\t\n 891:\t\t/* Get EN GPIO */\n 892:\t\tphy-\u003egpiod_en = devm_gpiod_get(dev, \"enable\", GPIOD_OUT_LOW);\n 893:\t\tif (IS_ERR(phy-\u003egpiod_en)) {\n 894:\t\t\tnfc_err(dev, \"Unable to get EN GPIO\\n\");\n 895:\t\t\treturn PTR_ERR(phy-\u003egpiod_en);\n 896:\t\t}\n 897:\t\n 898:\t\t/* Get FW GPIO */\n 899:\t\tphy-\u003egpiod_fw = devm_gpiod_get(dev, \"firmware\", GPIOD_OUT_LOW);\n 900:\t\tif (IS_ERR(phy-\u003egpiod_fw)) {\n 901:\t\t\tnfc_err(dev, \"Unable to get FW GPIO\\n\");\n 902:\t\t\treturn PTR_ERR(phy-\u003egpiod_fw);\n 903:\t\t}\n 904:\t\n 905:\t\tpn544_hci_i2c_platform_init(phy);\n 906:\t\n 907:\t\tr = devm_request_threaded_irq(\u0026client-\u003edev, client-\u003eirq, NULL,\n 908:\t\t\t\t\t      pn544_hci_i2c_irq_thread_fn,\n 909:\t\t\t\t\t      IRQF_TRIGGER_RISING | IRQF_ONESHOT,\n 910:\t\t\t\t\t      PN544_HCI_I2C_DRIVER_NAME, phy);\n 911:\t\tif (r \u003c 0) {\n 912:\t\t\tnfc_err(\u0026client-\u003edev, \"Unable to register IRQ handler\\n\");\n 913:\t\t\treturn r;\n 914:\t\t}\n 915:\t\n 916:\t\tr = pn544_hci_probe(phy, \u0026i2c_phy_ops, LLC_SHDLC_NAME,\n 917:\t\t\t\t    PN544_I2C_FRAME_HEADROOM, PN544_I2C_FRAME_TAILROOM,\n 918:\t\t\t\t    PN544_HCI_I2C_LLC_MAX_PAYLOAD,\n 919:\t\t\t\t    pn544_hci_i2c_fw_download, \u0026phy-\u003ehdev);\n"
}

gemini-3.8-flash

null

null

							input: 40523
							output: 32
							thoughts: 2070
						

**Analyzing the syzkaller-found NFC HCI Bug**

Okay, first things first: I need to figure out how syzkaller found this bug. The commit message mentions "syz-cluster", but was this a direct syzkaller report, or did it leverage an existing test case related to `nfc_hci_create_pipe` or a similar function? Time to dig into the git log and see if I can find a relevant syzkaller test case or report for `net/nfc/hci/command.c`. I'll start by searching for `nfc_hci_create_pipe`, and I'll expand the search to include "NFC_HCI_INVALID_PIPE" in case the error handling is related.

Okay, I've got the patch. It introduces checks in `nfc_hci_create_pipe` for response length and pipe value. The fact that this patch was even needed raises a red flag. Why wasn't this handled before?

Now, is NFC HCI fuzzed by syzkaller? That's the key question. I need to consult the `WorthFuzzing` guide. It clearly outlines the criteria.

The guide says "WorthFuzzing=false" if the changes are non-kernel, unreachable hardware, or unreachable execution paths. This doesn't seem to fit here. This is modifying executable C code. This isn't vendor-specific hardware requiring special emulation. It's the NFC HCI protocol layer, which lives under `net/nfc/hci/`. Is NFC HCI a network protocol or core subsystem? Yes, it is located under the `net/` directory.

The next question: Does QEMU support NFC? Can I create an NFC device in QEMU? I need to figure out if there is an emulated NFC device, or a virtual one. I need to verify if NFC devices can exist in a virtual environment like QEMU. ST-NCI uses `nci_hci_dev_session_init`, which means the Linux virtual environment supports NFC! Now, what about an I2C device? Can I2C devices be dynamically instantiated in Linux via `i2c_new_client_device`? I know that I2C devices can be instantiated dynamically in Linux. If this is possible, maybe syzkaller has an I2C driver.

So the question is, can I2C devices be emulated in QEMU? Or does syzkaller have an I2C driver? Let's search the git log or grepper to see if there are other commits or syzkaller bugs in `net/nfc/hci/`. Then I will also check the commit messages and comments in `net/nfc/hci/core.c` or `command.c` to see if there are any hints.

no matches

{
  "Expression": "Reported-by: syzbot",
  "PathPrefix": "net/nfc"
}

{
  "error": "no matches"
}

gemini-3.8-flash

null

null

							input: 43238
							output: 29
							thoughts: 71
						

Okay, here's my summary, framed as my internal thought process:

**Investigating NFC_HCI within the Kernel Build System**

Right, so `grepper` isn't going to help me sift through commit history for the `NFC_HCI` configuration option. Damn, that's usually my go-to. I was about to reach for `git log` and see if I could find some related commits, but then it struck me – I don't actually need the full history to figure this out. I can take a smarter route. I should just look directly at the build configuration files.

Okay, let's target the relevant directory... `net/nfc/`. That's where I'd expect to find the Kconfig files. Now, the key is to understand how `NFC_HCI` is *selected* or *depended* upon. I'll check all the Kconfig files in there, and hopefully, I'll quickly find the relevant dependencies. No need for a general search; I can be targeted and efficient.

{
  "Expression": "NFC_HCI",
  "PathPrefix": "net/nfc"
}

{
  "Output": "net/nfc/Makefile=7=obj-$(CONFIG_NFC_NCI) += nci/\nnet/nfc/Makefile:8:obj-$(CONFIG_NFC_HCI) += hci/\nnet/nfc/Makefile-9-obj-$(CONFIG_NFC_DIGITAL) += nfc_digital.o\n--\nnet/nfc/hci/Kconfig-1-# SPDX-License-Identifier: GPL-2.0-only\nnet/nfc/hci/Kconfig:2:config NFC_HCI\nnet/nfc/hci/Kconfig-3-\tdepends on NFC\n--\nnet/nfc/hci/Kconfig=11=config NFC_SHDLC\nnet/nfc/hci/Kconfig:12:\tdepends on NFC_HCI\nnet/nfc/hci/Kconfig-13-\tselect CRC_CCITT\n--\nnet/nfc/hci/Makefile-5-\nnet/nfc/hci/Makefile:6:obj-$(CONFIG_NFC_HCI) += hci.o\nnet/nfc/hci/Makefile-7-\n--\nnet/nfc/hci/command.c=19=static int nfc_hci_execute_cmd_async(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,\n--\nnet/nfc/hci/command.c-28-\t */\nnet/nfc/hci/command.c:29:\treturn nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_COMMAND, cmd,\nnet/nfc/hci/command.c-30-\t\t\t\t      param, param_len, cb, cb_context, MAX_FWI);\n--\nnet/nfc/hci/command.c=55=static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,\n--\nnet/nfc/hci/command.c-71-\thcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,\nnet/nfc/hci/command.c:72:\t\t\t\t\t\t    NFC_HCI_HCP_COMMAND, cmd,\nnet/nfc/hci/command.c-73-\t\t\t\t\t\t    param, param_len,\n--\nnet/nfc/hci/command.c=91=int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,\n--\nnet/nfc/hci/command.c-98-\tpipe = hdev-\u003egate2pipe[gate];\nnet/nfc/hci/command.c:99:\tif (pipe == NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-100-\t\treturn -EADDRNOTAVAIL;\nnet/nfc/hci/command.c-101-\nnet/nfc/hci/command.c:102:\treturn nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,\nnet/nfc/hci/command.c-103-\t\t\t\t      param, param_len, NULL, NULL, 0);\n--\nnet/nfc/hci/command.c=112=int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,\n--\nnet/nfc/hci/command.c-117-\tpipe = hdev-\u003egate2pipe[gate];\nnet/nfc/hci/command.c:118:\tif (pipe == NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-119-\t\treturn -EADDRNOTAVAIL;\n--\nnet/nfc/hci/command.c=125=int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,\n--\nnet/nfc/hci/command.c-131-\tpipe = hdev-\u003egate2pipe[gate];\nnet/nfc/hci/command.c:132:\tif (pipe == NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-133-\t\treturn -EADDRNOTAVAIL;\n--\nnet/nfc/hci/command.c=140=int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,\n--\nnet/nfc/hci/command.c-162-\nnet/nfc/hci/command.c:163:\tr = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,\nnet/nfc/hci/command.c-164-\t\t\t     tmp, param_len + 1, NULL);\n--\nnet/nfc/hci/command.c=172=int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,\n--\nnet/nfc/hci/command.c-176-\nnet/nfc/hci/command.c:177:\treturn nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,\nnet/nfc/hci/command.c-178-\t\t\t\t\u0026idx, 1, skb);\n--\nnet/nfc/hci/command.c=182=static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)\n--\nnet/nfc/hci/command.c-188-\nnet/nfc/hci/command.c:189:\tr = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,\nnet/nfc/hci/command.c-190-\t\t\t\tNULL, 0, \u0026skb);\n--\nnet/nfc/hci/command.c=202=static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)\nnet/nfc/hci/command.c-203-{\nnet/nfc/hci/command.c:204:\treturn nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,\nnet/nfc/hci/command.c-205-\t\t\t\t   NULL, 0, NULL);\n--\nnet/nfc/hci/command.c=208=static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,\n--\nnet/nfc/hci/command.c-217-\nnet/nfc/hci/command.c:218:\tparams.src_gate = NFC_HCI_ADMIN_GATE;\nnet/nfc/hci/command.c-219-\tparams.dest_host = dest_host;\n--\nnet/nfc/hci/command.c-221-\nnet/nfc/hci/command.c:222:\t*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\nnet/nfc/hci/command.c:223:\t\t\t\t      NFC_HCI_ADM_CREATE_PIPE,\nnet/nfc/hci/command.c-224-\t\t\t\t      (u8 *) \u0026params, sizeof(params), \u0026skb);\nnet/nfc/hci/command.c-225-\tif (*result \u003c 0)\nnet/nfc/hci/command.c:226:\t\treturn NFC_HCI_INVALID_PIPE;\nnet/nfc/hci/command.c-227-\n--\nnet/nfc/hci/command.c-230-\t\t*result = -EPROTO;\nnet/nfc/hci/command.c:231:\t\treturn NFC_HCI_INVALID_PIPE;\nnet/nfc/hci/command.c-232-\t}\n--\nnet/nfc/hci/command.c-236-\nnet/nfc/hci/command.c:237:\tif (pipe \u003e= NFC_HCI_MAX_PIPES) {\nnet/nfc/hci/command.c-238-\t\t*result = -EINVAL;\nnet/nfc/hci/command.c:239:\t\treturn NFC_HCI_INVALID_PIPE;\nnet/nfc/hci/command.c-240-\t}\n--\nnet/nfc/hci/command.c=246=static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)\nnet/nfc/hci/command.c-247-{\nnet/nfc/hci/command.c:248:\treturn nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\nnet/nfc/hci/command.c:249:\t\t\t\t   NFC_HCI_ADM_DELETE_PIPE, \u0026pipe, 1, NULL);\nnet/nfc/hci/command.c-250-}\n--\nnet/nfc/hci/command.c=252=static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)\n--\nnet/nfc/hci/command.c-259-\nnet/nfc/hci/command.c:260:\tif (test_bit(NFC_HCI_QUIRK_SHORT_CLEAR, \u0026hdev-\u003equirks))\nnet/nfc/hci/command.c-261-\t\tparam_len = 0;\nnet/nfc/hci/command.c-262-\nnet/nfc/hci/command.c:263:\treturn nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\nnet/nfc/hci/command.c:264:\t\t\t\t   NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,\nnet/nfc/hci/command.c-265-\t\t\t\t   NULL);\n--\nnet/nfc/hci/command.c=268=int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)\n--\nnet/nfc/hci/command.c-272-\nnet/nfc/hci/command.c:273:\tif (pipe == NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-274-\t\treturn -EADDRNOTAVAIL;\n--\nnet/nfc/hci/command.c-279-\nnet/nfc/hci/command.c:280:\tif (pipe != NFC_HCI_LINK_MGMT_PIPE \u0026\u0026 pipe != NFC_HCI_ADMIN_PIPE) {\nnet/nfc/hci/command.c-281-\t\tr = nfc_hci_delete_pipe(hdev, pipe);\n--\nnet/nfc/hci/command.c-285-\nnet/nfc/hci/command.c:286:\thdev-\u003egate2pipe[gate] = NFC_HCI_INVALID_PIPE;\nnet/nfc/hci/command.c-287-\n--\nnet/nfc/hci/command.c=306=int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,\n--\nnet/nfc/hci/command.c-311-\nnet/nfc/hci/command.c:312:\tif (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)\nnet/nfc/hci/command.c-313-\t\treturn 0;\nnet/nfc/hci/command.c-314-\nnet/nfc/hci/command.c:315:\tif (hdev-\u003egate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-316-\t\treturn -EADDRINUSE;\nnet/nfc/hci/command.c-317-\nnet/nfc/hci/command.c:318:\tif (pipe != NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-319-\t\tgoto open_pipe;\n--\nnet/nfc/hci/command.c-321-\tswitch (dest_gate) {\nnet/nfc/hci/command.c:322:\tcase NFC_HCI_LINK_MGMT_GATE:\nnet/nfc/hci/command.c:323:\t\tpipe = NFC_HCI_LINK_MGMT_PIPE;\nnet/nfc/hci/command.c-324-\t\tbreak;\nnet/nfc/hci/command.c:325:\tcase NFC_HCI_ADMIN_GATE:\nnet/nfc/hci/command.c:326:\t\tpipe = NFC_HCI_ADMIN_PIPE;\nnet/nfc/hci/command.c-327-\t\tbreak;\n--\nnet/nfc/hci/command.c-329-\t\tpipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, \u0026r);\nnet/nfc/hci/command.c:330:\t\tif (pipe == NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-331-\t\t\treturn r;\n--\nnet/nfc/hci/core.c=22=int nfc_hci_result_to_errno(u8 result)\n--\nnet/nfc/hci/core.c-24-\tswitch (result) {\nnet/nfc/hci/core.c:25:\tcase NFC_HCI_ANY_OK:\nnet/nfc/hci/core.c-26-\t\treturn 0;\nnet/nfc/hci/core.c:27:\tcase NFC_HCI_ANY_E_REG_PAR_UNKNOWN:\nnet/nfc/hci/core.c-28-\t\treturn -EOPNOTSUPP;\nnet/nfc/hci/core.c:29:\tcase NFC_HCI_ANY_E_TIMEOUT:\nnet/nfc/hci/core.c-30-\t\treturn -ETIME;\n--\nnet/nfc/hci/core.c=37=void nfc_hci_reset_pipes(struct nfc_hci_dev *hdev)\n--\nnet/nfc/hci/core.c-40-\nnet/nfc/hci/core.c:41:\tfor (i = 0; i \u003c NFC_HCI_MAX_PIPES; i++) {\nnet/nfc/hci/core.c:42:\t\thdev-\u003epipes[i].gate = NFC_HCI_INVALID_GATE;\nnet/nfc/hci/core.c:43:\t\thdev-\u003epipes[i].dest_host = NFC_HCI_INVALID_HOST;\nnet/nfc/hci/core.c-44-\t}\nnet/nfc/hci/core.c:45:\tmemset(hdev-\u003egate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev-\u003egate2pipe));\nnet/nfc/hci/core.c-46-}\n--\nnet/nfc/hci/core.c=49=void nfc_hci_reset_pipes_per_host(struct nfc_hci_dev *hdev, u8 host)\n--\nnet/nfc/hci/core.c-52-\nnet/nfc/hci/core.c:53:\tfor (i = 0; i \u003c NFC_HCI_MAX_PIPES; i++) {\nnet/nfc/hci/core.c-54-\t\tif (hdev-\u003epipes[i].dest_host != host)\n--\nnet/nfc/hci/core.c-56-\nnet/nfc/hci/core.c:57:\t\thdev-\u003epipes[i].gate = NFC_HCI_INVALID_GATE;\nnet/nfc/hci/core.c:58:\t\thdev-\u003epipes[i].dest_host = NFC_HCI_INVALID_HOST;\nnet/nfc/hci/core.c-59-\t}\n--\nnet/nfc/hci/core.c=126=static void nfc_hci_msg_rx_work(struct work_struct *work)\n--\nnet/nfc/hci/core.c-137-\t\tpipe = skb-\u003edata[0];\nnet/nfc/hci/core.c:138:\t\tskb_pull(skb, NFC_HCI_HCP_PACKET_HEADER_LEN);\nnet/nfc/hci/core.c-139-\t\tmessage = (struct hcp_message *)skb-\u003edata;\n--\nnet/nfc/hci/core.c-141-\t\tinstruction = HCP_MSG_GET_CMD(message-\u003eheader);\nnet/nfc/hci/core.c:142:\t\tskb_pull(skb, NFC_HCI_HCP_MESSAGE_HEADER_LEN);\nnet/nfc/hci/core.c-143-\n--\nnet/nfc/hci/core.c=181=void nfc_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,\n--\nnet/nfc/hci/core.c-183-{\nnet/nfc/hci/core.c:184:\tu8 status = NFC_HCI_ANY_OK;\nnet/nfc/hci/core.c-185-\tconst struct hci_create_pipe_resp *create_info;\n--\nnet/nfc/hci/core.c-191-\nnet/nfc/hci/core.c:192:\tif (pipe \u003e= NFC_HCI_MAX_PIPES) {\nnet/nfc/hci/core.c:193:\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-194-\t\tgoto exit;\n--\nnet/nfc/hci/core.c-199-\tswitch (cmd) {\nnet/nfc/hci/core.c:200:\tcase NFC_HCI_ADM_NOTIFY_PIPE_CREATED:\nnet/nfc/hci/core.c-201-\t\tif (skb-\u003elen != 5) {\nnet/nfc/hci/core.c:202:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-203-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-206-\nnet/nfc/hci/core.c:207:\t\tif (create_info-\u003epipe \u003e= NFC_HCI_MAX_PIPES) {\nnet/nfc/hci/core.c:208:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-209-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-221-\t\tbreak;\nnet/nfc/hci/core.c:222:\tcase NFC_HCI_ANY_OPEN_PIPE:\nnet/nfc/hci/core.c:223:\t\tif (gate == NFC_HCI_INVALID_GATE) {\nnet/nfc/hci/core.c:224:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-225-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-227-\t\tbreak;\nnet/nfc/hci/core.c:228:\tcase NFC_HCI_ADM_NOTIFY_PIPE_DELETED:\nnet/nfc/hci/core.c-229-\t\tif (skb-\u003elen != 1) {\nnet/nfc/hci/core.c:230:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-231-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-234-\nnet/nfc/hci/core.c:235:\t\tif (delete_info-\u003epipe \u003e= NFC_HCI_MAX_PIPES) {\nnet/nfc/hci/core.c:236:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-237-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-239-\nnet/nfc/hci/core.c:240:\t\thdev-\u003epipes[delete_info-\u003epipe].gate = NFC_HCI_INVALID_GATE;\nnet/nfc/hci/core.c:241:\t\thdev-\u003epipes[delete_info-\u003epipe].dest_host = NFC_HCI_INVALID_HOST;\nnet/nfc/hci/core.c-242-\t\tbreak;\nnet/nfc/hci/core.c:243:\tcase NFC_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED:\nnet/nfc/hci/core.c-244-\t\tif (skb-\u003elen != 1) {\nnet/nfc/hci/core.c:245:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-246-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-260-exit:\nnet/nfc/hci/core.c:261:\tnfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_RESPONSE,\nnet/nfc/hci/core.c-262-\t\t\t       status, NULL, 0, NULL, NULL, 0);\n--\nnet/nfc/hci/core.c=267=u32 nfc_hci_sak_to_protocol(u8 sak)\nnet/nfc/hci/core.c-268-{\nnet/nfc/hci/core.c:269:\tswitch (NFC_HCI_TYPE_A_SEL_PROT(sak)) {\nnet/nfc/hci/core.c:270:\tcase NFC_HCI_TYPE_A_SEL_PROT_MIFARE:\nnet/nfc/hci/core.c-271-\t\treturn NFC_PROTO_MIFARE_MASK;\nnet/nfc/hci/core.c:272:\tcase NFC_HCI_TYPE_A_SEL_PROT_ISO14443:\nnet/nfc/hci/core.c-273-\t\treturn NFC_PROTO_ISO14443_MASK;\nnet/nfc/hci/core.c:274:\tcase NFC_HCI_TYPE_A_SEL_PROT_DEP:\nnet/nfc/hci/core.c-275-\t\treturn NFC_PROTO_NFC_DEP_MASK;\nnet/nfc/hci/core.c:276:\tcase NFC_HCI_TYPE_A_SEL_PROT_ISO14443_DEP:\nnet/nfc/hci/core.c-277-\t\treturn NFC_PROTO_ISO14443_MASK | NFC_PROTO_NFC_DEP_MASK;\n--\nnet/nfc/hci/core.c=284=int nfc_hci_target_discovered(struct nfc_hci_dev *hdev, u8 gate)\n--\nnet/nfc/hci/core.c-298-\tswitch (gate) {\nnet/nfc/hci/core.c:299:\tcase NFC_HCI_RF_READER_A_GATE:\nnet/nfc/hci/core.c:300:\t\tr = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:301:\t\t\t\t      NFC_HCI_RF_READER_A_ATQA, \u0026atqa_skb);\nnet/nfc/hci/core.c-302-\t\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c-304-\nnet/nfc/hci/core.c:305:\t\tr = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:306:\t\t\t\t      NFC_HCI_RF_READER_A_SAK, \u0026sak_skb);\nnet/nfc/hci/core.c-307-\t\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c-324-\nnet/nfc/hci/core.c:325:\t\tr = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:326:\t\t\t\t      NFC_HCI_RF_READER_A_UID, \u0026uid_skb);\nnet/nfc/hci/core.c-327-\t\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c-344-\t\tbreak;\nnet/nfc/hci/core.c:345:\tcase NFC_HCI_RF_READER_B_GATE:\nnet/nfc/hci/core.c-346-\t\ttargets-\u003esupported_protocols = NFC_PROTO_ISO14443_B_MASK;\n--\nnet/nfc/hci/core.c=381=void nfc_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe, u8 event,\n--\nnet/nfc/hci/core.c-386-\nnet/nfc/hci/core.c:387:\tif (pipe \u003e= NFC_HCI_MAX_PIPES) {\nnet/nfc/hci/core.c-388-\t\tpr_err(\"Discarded event %x to invalid pipe %x\\n\", event, pipe);\n--\nnet/nfc/hci/core.c-392-\tgate = hdev-\u003epipes[pipe].gate;\nnet/nfc/hci/core.c:393:\tif (gate == NFC_HCI_INVALID_GATE) {\nnet/nfc/hci/core.c-394-\t\tpr_err(\"Discarded event %x to unopened pipe %x\\n\", event, pipe);\n--\nnet/nfc/hci/core.c-404-\tswitch (event) {\nnet/nfc/hci/core.c:405:\tcase NFC_HCI_EVT_TARGET_DISCOVERED:\nnet/nfc/hci/core.c-406-\t\tif (skb-\u003elen \u003c 1) {\t/* no status data? */\n--\nnet/nfc/hci/core.c=449=static int hci_dev_connect_gates(struct nfc_hci_dev *hdev, u8 gate_count,\n--\nnet/nfc/hci/core.c-453-\twhile (gate_count--) {\nnet/nfc/hci/core.c:454:\t\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\nnet/nfc/hci/core.c-455-\t\t\t\t\t gates-\u003egate, gates-\u003epipe);\n--\nnet/nfc/hci/core.c=464=static int hci_dev_session_init(struct nfc_hci_dev *hdev)\n--\nnet/nfc/hci/core.c-468-\nnet/nfc/hci/core.c:469:\tif (hdev-\u003einit_data.gates[0].gate != NFC_HCI_ADMIN_GATE)\nnet/nfc/hci/core.c-470-\t\treturn -EPROTO;\nnet/nfc/hci/core.c-471-\nnet/nfc/hci/core.c:472:\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\nnet/nfc/hci/core.c-473-\t\t\t\t hdev-\u003einit_data.gates[0].gate,\n--\nnet/nfc/hci/core.c-477-\nnet/nfc/hci/core.c:478:\tr = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,\nnet/nfc/hci/core.c:479:\t\t\t      NFC_HCI_ADMIN_SESSION_IDENTITY, \u0026skb);\nnet/nfc/hci/core.c-480-\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c-502-\nnet/nfc/hci/core.c:503:\t\tr = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,\nnet/nfc/hci/core.c:504:\t\t\t\tNFC_HCI_ADMIN_SESSION_IDENTITY,\nnet/nfc/hci/core.c-505-\t\t\t\thdev-\u003einit_data.session_id,\n--\nnet/nfc/hci/core.c=520=static int hci_dev_version(struct nfc_hci_dev *hdev)\n--\nnet/nfc/hci/core.c-524-\nnet/nfc/hci/core.c:525:\tr = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,\nnet/nfc/hci/core.c:526:\t\t\t      NFC_HCI_ID_MGMT_VERSION_SW, \u0026skb);\nnet/nfc/hci/core.c-527-\tif (r == -EOPNOTSUPP) {\n--\nnet/nfc/hci/core.c-545-\nnet/nfc/hci/core.c:546:\tr = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,\nnet/nfc/hci/core.c:547:\t\t\t      NFC_HCI_ID_MGMT_VERSION_HW, \u0026skb);\nnet/nfc/hci/core.c-548-\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c=579=static int hci_dev_up(struct nfc_dev *nfc_dev)\n--\nnet/nfc/hci/core.c-597-\nnet/nfc/hci/core.c:598:\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:599:\t\t\t       NFC_HCI_EVT_END_OPERATION, NULL, 0);\nnet/nfc/hci/core.c-600-\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c=639=static int hci_start_poll(struct nfc_dev *nfc_dev,\n--\nnet/nfc/hci/core.c-646-\telse\nnet/nfc/hci/core.c:647:\t\treturn nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:648:\t\t\t\t\t  NFC_HCI_EVT_READER_REQUESTED,\nnet/nfc/hci/core.c-649-\t\t\t\t\t  NULL, 0);\n--\nnet/nfc/hci/core.c=652=static void hci_stop_poll(struct nfc_dev *nfc_dev)\n--\nnet/nfc/hci/core.c-658-\telse\nnet/nfc/hci/core.c:659:\t\tnfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:660:\t\t\t\t   NFC_HCI_EVT_END_OPERATION, NULL, 0);\nnet/nfc/hci/core.c-661-}\n--\nnet/nfc/hci/core.c=722=static int hci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,\n--\nnet/nfc/hci/core.c-731-\tswitch (target-\u003ehci_reader_gate) {\nnet/nfc/hci/core.c:732:\tcase NFC_HCI_RF_READER_A_GATE:\nnet/nfc/hci/core.c:733:\tcase NFC_HCI_RF_READER_B_GATE:\nnet/nfc/hci/core.c-734-\t\tif (hdev-\u003eops-\u003eim_transceive) {\n--\nnet/nfc/hci/core.c-747-\t\tr = nfc_hci_send_cmd_async(hdev, target-\u003ehci_reader_gate,\nnet/nfc/hci/core.c:748:\t\t\t\t\t   NFC_HCI_WR_XCHG_DATA, skb-\u003edata,\nnet/nfc/hci/core.c-749-\t\t\t\t\t   skb-\u003elen, hci_transceive_cb, hdev);\n--\nnet/nfc/hci/core.c=854=static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb)\n--\nnet/nfc/hci/core.c-863-\nnet/nfc/hci/core.c:864:\tif (!pskb_may_pull(skb, NFC_HCI_HCP_PACKET_HEADER_LEN)) {\nnet/nfc/hci/core.c-865-\t\tkfree_skb(skb);\n--\nnet/nfc/hci/core.c-869-\tpacket = (struct hcp_packet *)skb-\u003edata;\nnet/nfc/hci/core.c:870:\tif ((packet-\u003eheader \u0026 ~NFC_HCI_FRAGMENT) == 0) {\nnet/nfc/hci/core.c-871-\t\tskb_queue_tail(\u0026hdev-\u003erx_hcp_frags, skb);\n--\nnet/nfc/hci/core.c-876-\tif (skb_queue_len(\u0026hdev-\u003erx_hcp_frags)) {\nnet/nfc/hci/core.c:877:\t\tpipe = packet-\u003eheader \u0026 NFC_HCI_FRAGMENT;\nnet/nfc/hci/core.c-878-\t\tskb_queue_tail(\u0026hdev-\u003erx_hcp_frags, skb);\n--\nnet/nfc/hci/core.c-882-\t\t\tmsg_len += (frag_skb-\u003elen -\nnet/nfc/hci/core.c:883:\t\t\t\t    NFC_HCI_HCP_PACKET_HEADER_LEN);\nnet/nfc/hci/core.c-884-\t\t}\nnet/nfc/hci/core.c-885-\nnet/nfc/hci/core.c:886:\t\thcp_skb = nfc_alloc_recv_skb(NFC_HCI_HCP_PACKET_HEADER_LEN +\nnet/nfc/hci/core.c-887-\t\t\t\t\t     msg_len, GFP_KERNEL);\n--\nnet/nfc/hci/core.c-895-\t\tskb_queue_walk(\u0026hdev-\u003erx_hcp_frags, frag_skb) {\nnet/nfc/hci/core.c:896:\t\t\tmsg_len = frag_skb-\u003elen - NFC_HCI_HCP_PACKET_HEADER_LEN;\nnet/nfc/hci/core.c-897-\t\t\tskb_put_data(hcp_skb,\nnet/nfc/hci/core.c:898:\t\t\t\t     frag_skb-\u003edata + NFC_HCI_HCP_PACKET_HEADER_LEN,\nnet/nfc/hci/core.c-899-\t\t\t\t     msg_len);\n--\nnet/nfc/hci/core.c-903-\t} else {\nnet/nfc/hci/core.c:904:\t\tpacket-\u003eheader \u0026= NFC_HCI_FRAGMENT;\nnet/nfc/hci/core.c-905-\t\thcp_skb = skb;\n--\nnet/nfc/hci/core.c-911-\t */\nnet/nfc/hci/core.c:912:\tif (!pskb_may_pull(hcp_skb, NFC_HCI_HCP_HEADER_LEN)) {\nnet/nfc/hci/core.c-913-\t\tkfree_skb(hcp_skb);\n--\nnet/nfc/hci/core.c-918-\ttype = HCP_MSG_GET_TYPE(packet-\u003emessage.header);\nnet/nfc/hci/core.c:919:\tif (type == NFC_HCI_HCP_RESPONSE) {\nnet/nfc/hci/core.c-920-\t\tpipe = packet-\u003eheader;\nnet/nfc/hci/core.c-921-\t\tinstruction = HCP_MSG_GET_CMD(packet-\u003emessage.header);\nnet/nfc/hci/core.c:922:\t\tskb_pull(hcp_skb, NFC_HCI_HCP_PACKET_HEADER_LEN +\nnet/nfc/hci/core.c:923:\t\t\t NFC_HCI_HCP_MESSAGE_HEADER_LEN);\nnet/nfc/hci/core.c-924-\t\tnfc_hci_hcp_message_rx(hdev, pipe, type, instruction, hcp_skb);\n--\nnet/nfc/hci/hci.h=60=struct hci_all_pipe_cleared_noti {\n--\nnet/nfc/hci/hci.h-63-\nnet/nfc/hci/hci.h:64:#define NFC_HCI_FRAGMENT\t0x7f\nnet/nfc/hci/hci.h-65-\n--\nnet/nfc/hci/hci.h=76=void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,\n--\nnet/nfc/hci/hci.h-79-/* HCP headers */\nnet/nfc/hci/hci.h:80:#define NFC_HCI_HCP_PACKET_HEADER_LEN\t1\nnet/nfc/hci/hci.h:81:#define NFC_HCI_HCP_MESSAGE_HEADER_LEN\t1\nnet/nfc/hci/hci.h:82:#define NFC_HCI_HCP_HEADER_LEN\t\t2\nnet/nfc/hci/hci.h-83-\nnet/nfc/hci/hci.h-84-/* HCP types */\nnet/nfc/hci/hci.h:85:#define NFC_HCI_HCP_COMMAND\t0x00\nnet/nfc/hci/hci.h:86:#define NFC_HCI_HCP_EVENT\t0x01\nnet/nfc/hci/hci.h:87:#define NFC_HCI_HCP_RESPONSE\t0x02\nnet/nfc/hci/hci.h-88-\nnet/nfc/hci/hci.h-89-/* Generic commands */\nnet/nfc/hci/hci.h:90:#define NFC_HCI_ANY_SET_PARAMETER\t0x01\nnet/nfc/hci/hci.h:91:#define NFC_HCI_ANY_GET_PARAMETER\t0x02\nnet/nfc/hci/hci.h:92:#define NFC_HCI_ANY_OPEN_PIPE\t\t0x03\nnet/nfc/hci/hci.h:93:#define NFC_HCI_ANY_CLOSE_PIPE\t\t0x04\nnet/nfc/hci/hci.h-94-\nnet/nfc/hci/hci.h-95-/* Reader RF commands */\nnet/nfc/hci/hci.h:96:#define NFC_HCI_WR_XCHG_DATA\t\t0x10\nnet/nfc/hci/hci.h-97-\nnet/nfc/hci/hci.h-98-/* Admin commands */\nnet/nfc/hci/hci.h:99:#define NFC_HCI_ADM_CREATE_PIPE\t\t\t0x10\nnet/nfc/hci/hci.h:100:#define NFC_HCI_ADM_DELETE_PIPE\t\t\t0x11\nnet/nfc/hci/hci.h:101:#define NFC_HCI_ADM_NOTIFY_PIPE_CREATED\t\t0x12\nnet/nfc/hci/hci.h:102:#define NFC_HCI_ADM_NOTIFY_PIPE_DELETED\t\t0x13\nnet/nfc/hci/hci.h:103:#define NFC_HCI_ADM_CLEAR_ALL_PIPE\t\t0x14\nnet/nfc/hci/hci.h:104:#define NFC_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED\t0x15\nnet/nfc/hci/hci.h-105-\nnet/nfc/hci/hci.h-106-/* Generic responses */\nnet/nfc/hci/hci.h:107:#define NFC_HCI_ANY_OK\t\t\t\t0x00\nnet/nfc/hci/hci.h:108:#define NFC_HCI_ANY_E_NOT_CONNECTED\t\t0x01\nnet/nfc/hci/hci.h:109:#define NFC_HCI_ANY_E_CMD_PAR_UNKNOWN\t\t0x02\nnet/nfc/hci/hci.h:110:#define NFC_HCI_ANY_E_NOK\t\t\t0x03\nnet/nfc/hci/hci.h:111:#define NFC_HCI_ANY_E_PIPES_FULL\t\t0x04\nnet/nfc/hci/hci.h:112:#define NFC_HCI_ANY_E_REG_PAR_UNKNOWN\t\t0x05\nnet/nfc/hci/hci.h:113:#define NFC_HCI_ANY_E_PIPE_NOT_OPENED\t\t0x06\nnet/nfc/hci/hci.h:114:#define NFC_HCI_ANY_E_CMD_NOT_SUPPORTED\t\t0x07\nnet/nfc/hci/hci.h:115:#define NFC_HCI_ANY_E_INHIBITED\t\t\t0x08\nnet/nfc/hci/hci.h:116:#define NFC_HCI_ANY_E_TIMEOUT\t\t\t0x09\nnet/nfc/hci/hci.h:117:#define NFC_HCI_ANY_E_REG_ACCESS_DENIED\t\t0x0a\nnet/nfc/hci/hci.h:118:#define NFC_HCI_ANY_E_PIPE_ACCESS_DENIED\t0x0b\nnet/nfc/hci/hci.h-119-\n--\nnet/nfc/hci/hcp.c=21=int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,\n--\nnet/nfc/hci/hcp.c-38-\tskb_queue_head_init(\u0026cmd-\u003emsg_frags);\nnet/nfc/hci/hcp.c:39:\tcmd-\u003ewait_response = (type == NFC_HCI_HCP_COMMAND) ? true : false;\nnet/nfc/hci/hcp.c-40-\tcmd-\u003ecb = cb;\n--\nnet/nfc/hci/hcp.c-49-\nnet/nfc/hci/hcp.c:50:\t\tif (NFC_HCI_HCP_PACKET_HEADER_LEN + hci_len \u003c=\nnet/nfc/hci/hcp.c-51-\t\t    hdev-\u003emax_data_link_payload)\n--\nnet/nfc/hci/hcp.c-54-\t\t\tdata_link_len = hdev-\u003emax_data_link_payload -\nnet/nfc/hci/hcp.c:55:\t\t\t\t\tNFC_HCI_HCP_PACKET_HEADER_LEN;\nnet/nfc/hci/hcp.c-56-\nnet/nfc/hci/hcp.c:57:\t\tskb_len = ndev-\u003etx_headroom + NFC_HCI_HCP_PACKET_HEADER_LEN +\nnet/nfc/hci/hcp.c-58-\t\t\t  data_link_len + ndev-\u003etx_tailroom;\n--\nnet/nfc/hci/hcp.c-67-\nnet/nfc/hci/hcp.c:68:\t\tskb_put(skb, NFC_HCI_HCP_PACKET_HEADER_LEN + data_link_len);\nnet/nfc/hci/hcp.c-69-\n--\nnet/nfc/hci/hcp.c-85-\t\tif (hci_len == 0)\nnet/nfc/hci/hcp.c:86:\t\t\tpacket-\u003eheader |= ~NFC_HCI_FRAGMENT;\nnet/nfc/hci/hcp.c-87-\n--\nnet/nfc/hci/hcp.c=117=void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,\n--\nnet/nfc/hci/hcp.c-120-\tswitch (type) {\nnet/nfc/hci/hcp.c:121:\tcase NFC_HCI_HCP_RESPONSE:\nnet/nfc/hci/hcp.c-122-\t\tnfc_hci_resp_received(hdev, instruction, skb);\nnet/nfc/hci/hcp.c-123-\t\tbreak;\nnet/nfc/hci/hcp.c:124:\tcase NFC_HCI_HCP_COMMAND:\nnet/nfc/hci/hcp.c-125-\t\tnfc_hci_cmd_received(hdev, pipe, instruction, skb);\nnet/nfc/hci/hcp.c-126-\t\tbreak;\nnet/nfc/hci/hcp.c:127:\tcase NFC_HCI_HCP_EVENT:\nnet/nfc/hci/hcp.c-128-\t\tnfc_hci_event_received(hdev, pipe, instruction, skb);\n"
}

gemini-3.8-flash

null

null

							input: 55071
							output: 29
							thoughts: 136
						

**Analyzing the NFC HCI Implementation**

Okay, let's break this down. I'm looking at `net/nfc/hci/command.c`, which, as I recall, is part of the `nfc_hci` kernel module (`hci.o`). First, I need to confirm how `NFC_HCI` is configured within the kernel. Is it built-in, or is it a loadable module? Time to consult the relevant Kconfig file.

Alright, here it is: `net/nfc/hci/Kconfig`. `NFC_HCI` is tristate, depending on NFC itself. And it defaults to 'n'. Right, that means it's not enabled by default. Now I need to understand the dependencies and how other drivers interact with `NFC_HCI`. Let's perform a comprehensive search through all the Kconfig files. A grep for `NFC_HCI` should give me the answer. This will reveal which drivers select or depend on it, giving me the bigger picture of its role in the NFC subsystem.

{
  "Expression": "NFC_HCI",
  "PathPrefix": "drivers/nfc"
}

{
  "Output": "drivers/nfc/Kconfig=21=config NFC_MEI_PHY\ndrivers/nfc/Kconfig-22-\ttristate \"MEI bus NFC device support\"\ndrivers/nfc/Kconfig:23:\tdepends on INTEL_MEI \u0026\u0026 NFC_HCI\ndrivers/nfc/Kconfig-24-\thelp\n--\ndrivers/nfc/microread/Kconfig=10=config NFC_MICROREAD_I2C\ndrivers/nfc/microread/Kconfig-11-\ttristate \"Inside Secure Microread device support (I2C)\"\ndrivers/nfc/microread/Kconfig:12:\tdepends on NFC_HCI \u0026\u0026 I2C \u0026\u0026 NFC_SHDLC\ndrivers/nfc/microread/Kconfig-13-\tselect NFC_MICROREAD\n--\ndrivers/nfc/microread/Kconfig=22=config NFC_MICROREAD_MEI\ndrivers/nfc/microread/Kconfig-23-\ttristate \"Inside Secure Microread device support (MEI)\"\ndrivers/nfc/microread/Kconfig:24:\tdepends on NFC_HCI \u0026\u0026 NFC_MEI_PHY\ndrivers/nfc/microread/Kconfig-25-\tselect NFC_MICROREAD\n--\ndrivers/nfc/microread/microread.c-22-/* Admin */\ndrivers/nfc/microread/microread.c:23:#define MICROREAD_GATE_ID_ADM NFC_HCI_ADMIN_GATE\ndrivers/nfc/microread/microread.c-24-#define MICROREAD_GATE_ID_MGT 0x01\n--\ndrivers/nfc/microread/microread.c-26-#define MICROREAD_GATE_ID_TESTRF 0x03\ndrivers/nfc/microread/microread.c:27:#define MICROREAD_GATE_ID_LOOPBACK NFC_HCI_LOOPBACK_GATE\ndrivers/nfc/microread/microread.c:28:#define MICROREAD_GATE_ID_IDT NFC_HCI_ID_MGMT_GATE\ndrivers/nfc/microread/microread.c:29:#define MICROREAD_GATE_ID_LMS NFC_HCI_LINK_MGMT_GATE\ndrivers/nfc/microread/microread.c-30-\n--\ndrivers/nfc/microread/microread.c-32-#define MICROREAD_GATE_ID_MREAD_GEN 0x10\ndrivers/nfc/microread/microread.c:33:#define MICROREAD_GATE_ID_MREAD_ISO_B NFC_HCI_RF_READER_B_GATE\ndrivers/nfc/microread/microread.c-34-#define MICROREAD_GATE_ID_MREAD_NFC_T1 0x12\ndrivers/nfc/microread/microread.c:35:#define MICROREAD_GATE_ID_MREAD_ISO_A NFC_HCI_RF_READER_A_GATE\ndrivers/nfc/microread/microread.c-36-#define MICROREAD_GATE_ID_MREAD_NFC_T3 0x14\n--\ndrivers/nfc/microread/microread.c-95-/* Events */\ndrivers/nfc/microread/microread.c:96:#define MICROREAD_EVT_MREAD_DISCOVERY_OCCURED NFC_HCI_EVT_TARGET_DISCOVERED\ndrivers/nfc/microread/microread.c-97-#define MICROREAD_EVT_MREAD_CARD_FOUND 0x3D\n--\ndrivers/nfc/microread/microread.c-109-#define MICROREAD_EMCF_T3_UID 0\ndrivers/nfc/microread/microread.c:110:#define MICROREAD_EVT_MREAD_DISCOVERY_START NFC_HCI_EVT_READER_REQUESTED\ndrivers/nfc/microread/microread.c-111-#define MICROREAD_EVT_MREAD_DISCOVERY_START_SOME 0x3E\ndrivers/nfc/microread/microread.c:112:#define MICROREAD_EVT_MREAD_DISCOVERY_STOP NFC_HCI_EVT_END_OPERATION\ndrivers/nfc/microread/microread.c-113-#define MICROREAD_EVT_MREAD_SIM_REQUESTS 0x3F\ndrivers/nfc/microread/microread.c:114:#define MICROREAD_EVT_MCARD_EXCHANGE NFC_HCI_EVT_TARGET_DISCOVERED\ndrivers/nfc/microread/microread.c-115-#define MICROREAD_EVT_P2P_INITIATOR_EXCHANGE_TO_RF 0x20\n--\ndrivers/nfc/microread/microread.c-126-/* Hosts IDs */\ndrivers/nfc/microread/microread.c:127:#define MICROREAD_ELT_ID_HDS NFC_HCI_TERMINAL_HOST_ID\ndrivers/nfc/microread/microread.c:128:#define MICROREAD_ELT_ID_SIM NFC_HCI_UICC_HOST_ID\ndrivers/nfc/microread/microread.c-129-#define MICROREAD_ELT_ID_SE1 0x03\n--\ndrivers/nfc/microread/microread.c=670=int microread_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\n--\ndrivers/nfc/microread/microread.c-693-\ndrivers/nfc/microread/microread.c:694:\tset_bit(NFC_HCI_QUIRK_SHORT_CLEAR, \u0026quirks);\ndrivers/nfc/microread/microread.c-695-\n--\ndrivers/nfc/pn544/Kconfig=10=config NFC_PN544_I2C\ndrivers/nfc/pn544/Kconfig-11-\ttristate \"NXP PN544 device support (I2C)\"\ndrivers/nfc/pn544/Kconfig:12:\tdepends on NFC_HCI \u0026\u0026 I2C \u0026\u0026 NFC_SHDLC\ndrivers/nfc/pn544/Kconfig-13-\tselect NFC_PN544\n--\ndrivers/nfc/pn544/Kconfig=21=config NFC_PN544_MEI\ndrivers/nfc/pn544/Kconfig-22-\ttristate \"NXP PN544 device support (MEI)\"\ndrivers/nfc/pn544/Kconfig:23:\tdepends on NFC_HCI \u0026\u0026 NFC_MEI_PHY\ndrivers/nfc/pn544/Kconfig-24-\tselect NFC_PN544\n--\ndrivers/nfc/pn544/pn544.c=22=enum pn544_state {\n--\ndrivers/nfc/pn544/pn544.c-35-\ndrivers/nfc/pn544/pn544.c:36:/* NFC_HCI_RF_READER_A_GATE additional registers and commands */\ndrivers/nfc/pn544/pn544.c-37-#define PN544_RF_READER_A_AUTO_ACTIVATION\t\t\t0x10\n--\ndrivers/nfc/pn544/pn544.c-44-\ndrivers/nfc/pn544/pn544.c:45:/* NFC_HCI_ID_MGMT_GATE additional registers */\ndrivers/nfc/pn544/pn544.c-46-#define PN544_ID_MGMT_FULL_VERSION_SW\t\t0x10\n--\ndrivers/nfc/pn544/pn544.c=88=static const struct nfc_hci_gate pn544_gates[] = {\ndrivers/nfc/pn544/pn544.c:89:\t{NFC_HCI_ADMIN_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:90:\t{NFC_HCI_LOOPBACK_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:91:\t{NFC_HCI_ID_MGMT_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:92:\t{NFC_HCI_LINK_MGMT_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:93:\t{NFC_HCI_RF_READER_B_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:94:\t{NFC_HCI_RF_READER_A_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:95:\t{PN544_SYS_MGMT_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:96:\t{PN544_SWP_MGMT_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:97:\t{PN544_POLLING_LOOP_MGMT_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:98:\t{PN544_NFC_WI_MGMT_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:99:\t{PN544_RF_READER_F_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:100:\t{PN544_RF_READER_JEWEL_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:101:\t{PN544_RF_READER_ISO15693_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:102:\t{PN544_RF_READER_NFCIP1_INITIATOR_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/pn544/pn544.c:103:\t{PN544_RF_READER_NFCIP1_TARGET_GATE, NFC_HCI_INVALID_PIPE}\ndrivers/nfc/pn544/pn544.c-104-};\n--\ndrivers/nfc/pn544/pn544.c=165=static int pn544_hci_ready(struct nfc_hci_dev *hdev)\n--\ndrivers/nfc/pn544/pn544.c-270-\ndrivers/nfc/pn544/pn544.c:271:\tparam[0] = NFC_HCI_UICC_HOST_ID;\ndrivers/nfc/pn544/pn544.c:272:\tr = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,\ndrivers/nfc/pn544/pn544.c:273:\t\t\t      NFC_HCI_ADMIN_WHITELIST, param, 1);\ndrivers/nfc/pn544/pn544.c-274-\tif (r \u003c 0)\n--\ndrivers/nfc/pn544/pn544.c-283-\tparam[0] = 0x0;\ndrivers/nfc/pn544/pn544.c:284:\tr = nfc_hci_set_param(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/pn544/pn544.c-285-\t\t\t      PN544_RF_READER_A_AUTO_ACTIVATION, param, 1);\n--\ndrivers/nfc/pn544/pn544.c-288-\ndrivers/nfc/pn544/pn544.c:289:\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/pn544/pn544.c:290:\t\t\t       NFC_HCI_EVT_END_OPERATION, NULL, 0);\ndrivers/nfc/pn544/pn544.c-291-\tif (r \u003c 0)\n--\ndrivers/nfc/pn544/pn544.c-305-\ndrivers/nfc/pn544/pn544.c:306:\tr = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,\ndrivers/nfc/pn544/pn544.c-307-\t\t\t      PN544_ID_MGMT_FULL_VERSION_SW, \u0026skb);\n--\ndrivers/nfc/pn544/pn544.c=332=static int pn544_hci_start_poll(struct nfc_hci_dev *hdev,\n--\ndrivers/nfc/pn544/pn544.c-345-\ndrivers/nfc/pn544/pn544.c:346:\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/pn544/pn544.c:347:\t\t\t       NFC_HCI_EVT_END_OPERATION, NULL, 0);\ndrivers/nfc/pn544/pn544.c-348-\tif (r \u003c 0)\n--\ndrivers/nfc/pn544/pn544.c-391-\t\t\t\tPN544_RF_READER_NFCIP1_INITIATOR_GATE,\ndrivers/nfc/pn544/pn544.c:392:\t\t\t\tNFC_HCI_EVT_END_OPERATION, NULL, 0);\ndrivers/nfc/pn544/pn544.c-393-\t\tif (r \u003c 0)\n--\ndrivers/nfc/pn544/pn544.c-409-\t\t\t\tPN544_RF_READER_NFCIP1_INITIATOR_GATE,\ndrivers/nfc/pn544/pn544.c:410:\t\t\t\tNFC_HCI_EVT_READER_REQUESTED, NULL, 0);\ndrivers/nfc/pn544/pn544.c-411-\t\tif (r \u003c 0)\n--\ndrivers/nfc/pn544/pn544.c-413-\t\t\t\t\tPN544_RF_READER_NFCIP1_INITIATOR_GATE,\ndrivers/nfc/pn544/pn544.c:414:\t\t\t\t\tNFC_HCI_EVT_END_OPERATION, NULL, 0);\ndrivers/nfc/pn544/pn544.c-415-\t}\n--\ndrivers/nfc/pn544/pn544.c-433-\ndrivers/nfc/pn544/pn544.c:434:\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/pn544/pn544.c:435:\t\t\t       NFC_HCI_EVT_READER_REQUESTED, NULL, 0);\ndrivers/nfc/pn544/pn544.c-436-\tif (r \u003c 0)\ndrivers/nfc/pn544/pn544.c:437:\t\tnfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/pn544/pn544.c:438:\t\t\t\t   NFC_HCI_EVT_END_OPERATION, NULL, 0);\ndrivers/nfc/pn544/pn544.c-439-\n--\ndrivers/nfc/pn544/pn544.c=473=static int pn544_hci_dep_link_down(struct nfc_hci_dev *hdev)\n--\ndrivers/nfc/pn544/pn544.c-476-\treturn nfc_hci_send_event(hdev, PN544_RF_READER_NFCIP1_INITIATOR_GATE,\ndrivers/nfc/pn544/pn544.c:477:\t\t\t\t\tNFC_HCI_EVT_END_OPERATION, NULL, 0);\ndrivers/nfc/pn544/pn544.c-478-}\n--\ndrivers/nfc/pn544/pn544.c=501=static int pn544_hci_complete_target_discovered(struct nfc_hci_dev *hdev,\n--\ndrivers/nfc/pn544/pn544.c-523-\ndrivers/nfc/pn544/pn544.c:524:\t\tr = nfc_hci_send_cmd(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/pn544/pn544.c-525-\t\t\t\t     PN544_RF_READER_CMD_ACTIVATE_NEXT,\n--\ndrivers/nfc/pn544/pn544.c-562-\t\tif (target-\u003esens_res == 0x4403)\t/* Type 4 Mifare DESFire */\ndrivers/nfc/pn544/pn544.c:563:\t\t\tr = nfc_hci_send_cmd(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/pn544/pn544.c-564-\t\t\t      PN544_RF_READER_A_CMD_CONTINUE_ACTIVATION,\n--\ndrivers/nfc/pn544/pn544.c=602=static int pn544_hci_im_transceive(struct nfc_hci_dev *hdev,\n--\ndrivers/nfc/pn544/pn544.c-612-\tswitch (target-\u003ehci_reader_gate) {\ndrivers/nfc/pn544/pn544.c:613:\tcase NFC_HCI_RF_READER_A_GATE:\ndrivers/nfc/pn544/pn544.c-614-\t\tif (target-\u003esupported_protocols \u0026 NFC_PROTO_MIFARE_MASK) {\n--\ndrivers/nfc/pn544/pn544.c=681=static int pn544_hci_check_presence(struct nfc_hci_dev *hdev,\n--\ndrivers/nfc/pn544/pn544.c-694-\ndrivers/nfc/pn544/pn544.c:695:\t\treturn nfc_hci_send_cmd(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/pn544/pn544.c-696-\t\t\t\t     PN544_RF_READER_CMD_ACTIVATE_NEXT,\n--\ndrivers/nfc/pn544/pn544.c=715=static int pn544_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe, u8 event,\n--\ndrivers/nfc/pn544/pn544.c-742-\tcase PN544_HCI_EVT_DEACTIVATED:\ndrivers/nfc/pn544/pn544.c:743:\t\tr = nfc_hci_send_event(hdev, gate, NFC_HCI_EVT_END_OPERATION,\ndrivers/nfc/pn544/pn544.c-744-\t\t\t\t       NULL, 0);\n--\ndrivers/nfc/st21nfca/Kconfig=10=config NFC_ST21NFCA_I2C\ndrivers/nfc/st21nfca/Kconfig-11-\ttristate \"STMicroelectronics ST21NFCA NFC driver (I2C)\"\ndrivers/nfc/st21nfca/Kconfig:12:\tdepends on NFC_HCI \u0026\u0026 I2C \u0026\u0026 NFC_SHDLC\ndrivers/nfc/st21nfca/Kconfig-13-\tselect NFC_ST21NFCA\n--\ndrivers/nfc/st21nfca/core.c=74=static const struct nfc_hci_gate st21nfca_gates[] = {\ndrivers/nfc/st21nfca/core.c:75:\t{NFC_HCI_ADMIN_GATE, NFC_HCI_ADMIN_PIPE},\ndrivers/nfc/st21nfca/core.c:76:\t{NFC_HCI_LINK_MGMT_GATE, NFC_HCI_LINK_MGMT_PIPE},\ndrivers/nfc/st21nfca/core.c-77-\t{ST21NFCA_DEVICE_MGNT_GATE, ST21NFCA_DEVICE_MGNT_PIPE},\ndrivers/nfc/st21nfca/core.c-78-\ndrivers/nfc/st21nfca/core.c:79:\t{NFC_HCI_LOOPBACK_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/st21nfca/core.c:80:\t{NFC_HCI_ID_MGMT_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/st21nfca/core.c:81:\t{NFC_HCI_RF_READER_B_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/st21nfca/core.c:82:\t{NFC_HCI_RF_READER_A_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/st21nfca/core.c:83:\t{ST21NFCA_RF_READER_F_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/st21nfca/core.c:84:\t{ST21NFCA_RF_READER_14443_3_A_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/st21nfca/core.c:85:\t{ST21NFCA_RF_READER_ISO15693_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/st21nfca/core.c:86:\t{ST21NFCA_RF_CARD_F_GATE, NFC_HCI_INVALID_PIPE},\ndrivers/nfc/st21nfca/core.c-87-\ndrivers/nfc/st21nfca/core.c-88-\t/* Secure element pipes are created by secure element host */\ndrivers/nfc/st21nfca/core.c:89:\t{ST21NFCA_CONNECTIVITY_GATE, NFC_HCI_DO_NOT_CREATE_PIPE},\ndrivers/nfc/st21nfca/core.c:90:\t{ST21NFCA_APDU_READER_GATE, NFC_HCI_DO_NOT_CREATE_PIPE},\ndrivers/nfc/st21nfca/core.c-91-};\n--\ndrivers/nfc/st21nfca/core.c=104=static int st21nfca_hci_load_session(struct nfc_hci_dev *hdev)\n--\ndrivers/nfc/st21nfca/core.c-110-\tu8 pipe_list[] = { ST21NFCA_DM_GETINFO_PIPE_LIST,\ndrivers/nfc/st21nfca/core.c:111:\t\tNFC_HCI_TERMINAL_HOST_ID\ndrivers/nfc/st21nfca/core.c-112-\t};\ndrivers/nfc/st21nfca/core.c-113-\tu8 pipe_info[] = { ST21NFCA_DM_GETINFO_PIPE_INFO,\ndrivers/nfc/st21nfca/core.c:114:\t\tNFC_HCI_TERMINAL_HOST_ID, 0\ndrivers/nfc/st21nfca/core.c-115-\t};\n--\ndrivers/nfc/st21nfca/core.c-125-\t * - get a pipe list for each host.\ndrivers/nfc/st21nfca/core.c:126:\t * (eg: NFC_HCI_HOST_CONTROLLER_ID for now).\ndrivers/nfc/st21nfca/core.c-127-\t * (TODO Later on UICC HOST and eSE HOST)\n--\ndrivers/nfc/st21nfca/core.c-133-\t */\ndrivers/nfc/st21nfca/core.c:134:\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\ndrivers/nfc/st21nfca/core.c-135-\t\t\t\tST21NFCA_DEVICE_MGNT_GATE,\n--\ndrivers/nfc/st21nfca/core.c-166-\t\tif (info-\u003edst_gate_id == ST21NFCA_APDU_READER_GATE \u0026\u0026\ndrivers/nfc/st21nfca/core.c:167:\t\t\tinfo-\u003esrc_host_id == NFC_HCI_UICC_HOST_ID) {\ndrivers/nfc/st21nfca/core.c-168-\t\t\tpr_err(\"Unexpected apdu_reader pipe on host %x\\n\",\n--\ndrivers/nfc/st21nfca/core.c-193-\t/*\ndrivers/nfc/st21nfca/core.c:194:\t * 3 gates have a well known pipe ID. Only NFC_HCI_LINK_MGMT_GATE\ndrivers/nfc/st21nfca/core.c-195-\t * is not yet open at this stage.\ndrivers/nfc/st21nfca/core.c-196-\t */\ndrivers/nfc/st21nfca/core.c:197:\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\ndrivers/nfc/st21nfca/core.c:198:\t\t\t\t NFC_HCI_LINK_MGMT_GATE,\ndrivers/nfc/st21nfca/core.c:199:\t\t\t\t NFC_HCI_LINK_MGMT_PIPE);\ndrivers/nfc/st21nfca/core.c-200-\n--\ndrivers/nfc/st21nfca/core.c=243=static int st21nfca_hci_ready(struct nfc_hci_dev *hdev)\n--\ndrivers/nfc/st21nfca/core.c-253-\tif (info-\u003ese_status-\u003eis_uicc_present)\ndrivers/nfc/st21nfca/core.c:254:\t\twhite_list[wl_size++] = NFC_HCI_UICC_HOST_ID;\ndrivers/nfc/st21nfca/core.c-255-\tif (info-\u003ese_status-\u003eis_ese_present)\n--\ndrivers/nfc/st21nfca/core.c-258-\tif (wl_size) {\ndrivers/nfc/st21nfca/core.c:259:\t\tr = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,\ndrivers/nfc/st21nfca/core.c:260:\t\t\t\t\tNFC_HCI_ADMIN_WHITELIST,\ndrivers/nfc/st21nfca/core.c-261-\t\t\t\t\t(u8 *) \u0026white_list, wl_size);\n--\ndrivers/nfc/st21nfca/core.c-282-\ndrivers/nfc/st21nfca/core.c:283:\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/st21nfca/core.c:284:\t\t\t       NFC_HCI_EVT_END_OPERATION, NULL, 0);\ndrivers/nfc/st21nfca/core.c-285-\tif (r \u003c 0)\n--\ndrivers/nfc/st21nfca/core.c-287-\ndrivers/nfc/st21nfca/core.c:288:\tr = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,\ndrivers/nfc/st21nfca/core.c:289:\t\t\t      NFC_HCI_ID_MGMT_VERSION_SW, \u0026skb);\ndrivers/nfc/st21nfca/core.c-290-\tif (r \u003c 0)\n--\ndrivers/nfc/st21nfca/core.c=314=static int st21nfca_hci_start_poll(struct nfc_hci_dev *hdev,\n--\ndrivers/nfc/st21nfca/core.c-324-\ndrivers/nfc/st21nfca/core.c:325:\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/st21nfca/core.c:326:\t\t\t       NFC_HCI_EVT_END_OPERATION, NULL, 0);\ndrivers/nfc/st21nfca/core.c-327-\tif (r \u003c 0)\n--\ndrivers/nfc/st21nfca/core.c-333-\t\t */\ndrivers/nfc/st21nfca/core.c:334:\t\tif ((NFC_HCI_RF_READER_B_GATE \u0026 im_protocols) == 0) {\ndrivers/nfc/st21nfca/core.c-335-\t\t\tr = nfc_hci_disconnect_gate(hdev,\ndrivers/nfc/st21nfca/core.c:336:\t\t\t\t\tNFC_HCI_RF_READER_B_GATE);\ndrivers/nfc/st21nfca/core.c-337-\t\t\tif (r \u003c 0)\n--\ndrivers/nfc/st21nfca/core.c-340-\ndrivers/nfc/st21nfca/core.c:341:\t\tif ((NFC_HCI_RF_READER_A_GATE \u0026 im_protocols) == 0) {\ndrivers/nfc/st21nfca/core.c-342-\t\t\tr = nfc_hci_disconnect_gate(hdev,\ndrivers/nfc/st21nfca/core.c:343:\t\t\t\t\tNFC_HCI_RF_READER_A_GATE);\ndrivers/nfc/st21nfca/core.c-344-\t\t\tif (r \u003c 0)\n--\ndrivers/nfc/st21nfca/core.c-393-\ndrivers/nfc/st21nfca/core.c:394:\t\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/st21nfca/core.c:395:\t\t\t\t       NFC_HCI_EVT_READER_REQUESTED, NULL, 0);\ndrivers/nfc/st21nfca/core.c-396-\t\tif (r \u003c 0)\ndrivers/nfc/st21nfca/core.c:397:\t\t\tnfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\ndrivers/nfc/st21nfca/core.c:398:\t\t\t\t\t   NFC_HCI_EVT_END_OPERATION, NULL, 0);\ndrivers/nfc/st21nfca/core.c-399-\t}\n--\ndrivers/nfc/st21nfca/core.c=806=static int st21nfca_hci_check_presence(struct nfc_hci_dev *hdev,\n--\ndrivers/nfc/st21nfca/core.c-811-\tswitch (target-\u003ehci_reader_gate) {\ndrivers/nfc/st21nfca/core.c:812:\tcase NFC_HCI_RF_READER_A_GATE:\ndrivers/nfc/st21nfca/core.c:813:\tcase NFC_HCI_RF_READER_B_GATE:\ndrivers/nfc/st21nfca/core.c-814-\t\t/*\n--\ndrivers/nfc/st21nfca/core.c=832=static void st21nfca_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,\n--\ndrivers/nfc/st21nfca/core.c-840-\tswitch (cmd) {\ndrivers/nfc/st21nfca/core.c:841:\tcase NFC_HCI_ANY_OPEN_PIPE:\ndrivers/nfc/st21nfca/core.c-842-\t\tif (gate != ST21NFCA_APDU_READER_GATE \u0026\u0026\ndrivers/nfc/st21nfca/core.c:843:\t\t\thdev-\u003epipes[pipe].dest_host != NFC_HCI_UICC_HOST_ID)\ndrivers/nfc/st21nfca/core.c-844-\t\t\tinfo-\u003ese_info.count_pipes++;\n--\ndrivers/nfc/st21nfca/core.c=889=static int st21nfca_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe,\n--\ndrivers/nfc/st21nfca/core.c-897-\tswitch (gate) {\ndrivers/nfc/st21nfca/core.c:898:\tcase NFC_HCI_ADMIN_GATE:\ndrivers/nfc/st21nfca/core.c-899-\t\treturn st21nfca_admin_event_received(hdev, event, skb);\n--\ndrivers/nfc/st21nfca/core.c-906-\t\treturn st21nfca_apdu_reader_event_received(hdev, event, skb);\ndrivers/nfc/st21nfca/core.c:907:\tcase NFC_HCI_LOOPBACK_GATE:\ndrivers/nfc/st21nfca/core.c-908-\t\treturn st21nfca_hci_loopback_event_received(hdev, event, skb);\n--\ndrivers/nfc/st21nfca/core.c=937=int st21nfca_hci_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,\n--\ndrivers/nfc/st21nfca/core.c-984-\ndrivers/nfc/st21nfca/core.c:985:\tset_bit(NFC_HCI_QUIRK_SHORT_CLEAR, \u0026quirks);\ndrivers/nfc/st21nfca/core.c-986-\n--\ndrivers/nfc/st21nfca/se.c=86=static int st21nfca_hci_control_se(struct nfc_hci_dev *hdev, u32 se_idx,\n--\ndrivers/nfc/st21nfca/se.c-94-\tswitch (se_idx) {\ndrivers/nfc/st21nfca/se.c:95:\tcase NFC_HCI_UICC_HOST_ID:\ndrivers/nfc/st21nfca/se.c-96-\t\tse_event = (state == ST21NFCA_SE_MODE_ON ?\n--\ndrivers/nfc/st21nfca/se.c-131-\ndrivers/nfc/st21nfca/se.c:132:\tr = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,\ndrivers/nfc/st21nfca/se.c:133:\t\t\tNFC_HCI_ADMIN_HOST_LIST,\ndrivers/nfc/st21nfca/se.c-134-\t\t\t\u0026sk_host_list);\n--\ndrivers/nfc/st21nfca/se.c=152=int st21nfca_hci_discover_se(struct nfc_hci_dev *hdev)\n--\ndrivers/nfc/st21nfca/se.c-160-\tif (info-\u003ese_status-\u003eis_uicc_present) {\ndrivers/nfc/st21nfca/se.c:161:\t\tnfc_add_se(hdev-\u003endev, NFC_HCI_UICC_HOST_ID, NFC_SE_UICC);\ndrivers/nfc/st21nfca/se.c-162-\t\tse_count++;\n--\ndrivers/nfc/st21nfca/vendor_cmds.c=247=static int st21nfca_hci_loopback(struct nfc_dev *dev, void *data,\n--\ndrivers/nfc/st21nfca/vendor_cmds.c-260-\ndrivers/nfc/st21nfca/vendor_cmds.c:261:\tr = nfc_hci_send_event(hdev, NFC_HCI_LOOPBACK_GATE,\ndrivers/nfc/st21nfca/vendor_cmds.c-262-\t\t\t       ST21NFCA_EVT_POST_DATA, data, data_len);\n"
}

gemini-3.8-flash

null

null

							input: 64932
							output: 31
							thoughts: 142
						

**Analyzing NFC Fuzzing Potential**

Okay, so I'm looking at `net/nfc/hci/command.c` in the Linux kernel. That puts me firmly within the `net/nfc/hci/` subsystem, which is good. The key question is, can syzkaller actually *fuzz* this area? I need to figure out if it's got the descriptions for NFC, or if I can even get to it.

Right, so NFC offers two entry points: there are the `AF_NFC` sockets, created via `socket(AF_NFC, ...)`, and then there’s the Generic Netlink family using the `NFC_GENL_NAME` ("nfc") name. I'll need to look at both. Specifically, I should check `net/nfc/netlink.c` and `net/nfc/af_nfc.c` to see how those are set up. From there, I can determine the potential for fuzzing and the specific areas that should be targeted by any fuzzing attempts. This seems like a reasonable approach.

{
  "Expression": "nfc_genl_family",
  "PathPrefix": "net/nfc"
}

{
  "Output": "net/nfc/netlink.c=25=static const struct genl_multicast_group nfc_genl_mcgrps[] = {\n--\nnet/nfc/netlink.c-28-\nnet/nfc/netlink.c:29:static struct genl_family nfc_genl_family;\nnet/nfc/netlink.c-30-static const struct nla_policy nfc_genl_policy[NFC_ATTR_MAX + 1] = {\n--\nnet/nfc/netlink.c=61=static int nfc_genl_send_target(struct sk_buff *msg, struct nfc_target *target,\n--\nnet/nfc/netlink.c-66-\thdr = genlmsg_put(msg, NETLINK_CB(cb-\u003eskb).portid, cb-\u003enlh-\u003enlmsg_seq,\nnet/nfc/netlink.c:67:\t\t\t  \u0026nfc_genl_family, flags, NFC_CMD_GET_TARGET);\nnet/nfc/netlink.c-68-\tif (!hdr)\n--\nnet/nfc/netlink.c=175=int nfc_genl_targets_found(struct nfc_dev *dev)\n--\nnet/nfc/netlink.c-185-\nnet/nfc/netlink.c:186:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-187-\t\t\t  NFC_EVENT_TARGETS_FOUND);\n--\nnet/nfc/netlink.c-195-\nnet/nfc/netlink.c:196:\treturn genlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_ATOMIC);\nnet/nfc/netlink.c-197-\n--\nnet/nfc/netlink.c=204=int nfc_genl_target_lost(struct nfc_dev *dev, u32 target_idx)\n--\nnet/nfc/netlink.c-212-\nnet/nfc/netlink.c:213:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-214-\t\t\t  NFC_EVENT_TARGET_LOST);\n--\nnet/nfc/netlink.c-223-\nnet/nfc/netlink.c:224:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_KERNEL);\nnet/nfc/netlink.c-225-\n--\nnet/nfc/netlink.c=234=int nfc_genl_tm_activated(struct nfc_dev *dev, u32 protocol)\n--\nnet/nfc/netlink.c-242-\nnet/nfc/netlink.c:243:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-244-\t\t\t  NFC_EVENT_TM_ACTIVATED);\n--\nnet/nfc/netlink.c-254-\nnet/nfc/netlink.c:255:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_KERNEL);\nnet/nfc/netlink.c-256-\n--\nnet/nfc/netlink.c=265=int nfc_genl_tm_deactivated(struct nfc_dev *dev)\n--\nnet/nfc/netlink.c-273-\nnet/nfc/netlink.c:274:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-275-\t\t\t  NFC_EVENT_TM_DEACTIVATED);\n--\nnet/nfc/netlink.c-283-\nnet/nfc/netlink.c:284:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_KERNEL);\nnet/nfc/netlink.c-285-\n--\nnet/nfc/netlink.c=305=int nfc_genl_device_added(struct nfc_dev *dev)\n--\nnet/nfc/netlink.c-313-\nnet/nfc/netlink.c:314:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-315-\t\t\t  NFC_EVENT_DEVICE_ADDED);\n--\nnet/nfc/netlink.c-323-\nnet/nfc/netlink.c:324:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_KERNEL);\nnet/nfc/netlink.c-325-\n--\nnet/nfc/netlink.c=334=int nfc_genl_device_removed(struct nfc_dev *dev)\n--\nnet/nfc/netlink.c-342-\nnet/nfc/netlink.c:343:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-344-\t\t\t  NFC_EVENT_DEVICE_REMOVED);\n--\nnet/nfc/netlink.c-352-\nnet/nfc/netlink.c:353:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_KERNEL);\nnet/nfc/netlink.c-354-\n--\nnet/nfc/netlink.c=363=int nfc_genl_llc_send_sdres(struct nfc_dev *dev, struct hlist_head *sdres_list)\n--\nnet/nfc/netlink.c-376-\nnet/nfc/netlink.c:377:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-378-\t\t\t  NFC_EVENT_LLC_SDRES);\n--\nnet/nfc/netlink.c-417-\nnet/nfc/netlink.c:418:\treturn genlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_ATOMIC);\nnet/nfc/netlink.c-419-\n--\nnet/nfc/netlink.c=429=int nfc_genl_se_added(struct nfc_dev *dev, u32 se_idx, u16 type)\n--\nnet/nfc/netlink.c-437-\nnet/nfc/netlink.c:438:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-439-\t\t\t  NFC_EVENT_SE_ADDED);\n--\nnet/nfc/netlink.c-449-\nnet/nfc/netlink.c:450:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_KERNEL);\nnet/nfc/netlink.c-451-\n--\nnet/nfc/netlink.c=460=int nfc_genl_se_removed(struct nfc_dev *dev, u32 se_idx)\n--\nnet/nfc/netlink.c-468-\nnet/nfc/netlink.c:469:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-470-\t\t\t  NFC_EVENT_SE_REMOVED);\n--\nnet/nfc/netlink.c-479-\nnet/nfc/netlink.c:480:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_KERNEL);\nnet/nfc/netlink.c-481-\n--\nnet/nfc/netlink.c=490=int nfc_genl_se_transaction(struct nfc_dev *dev, u8 se_idx,\n--\nnet/nfc/netlink.c-500-\nnet/nfc/netlink.c:501:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-502-\t\t\t  NFC_EVENT_SE_TRANSACTION);\n--\nnet/nfc/netlink.c-523-\nnet/nfc/netlink.c:524:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_KERNEL);\nnet/nfc/netlink.c-525-\n--\nnet/nfc/netlink.c=536=int nfc_genl_se_connectivity(struct nfc_dev *dev, u8 se_idx)\n--\nnet/nfc/netlink.c-545-\nnet/nfc/netlink.c:546:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-547-\t\t\t  NFC_EVENT_SE_CONNECTIVITY);\n--\nnet/nfc/netlink.c-561-\nnet/nfc/netlink.c:562:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_KERNEL);\nnet/nfc/netlink.c-563-\n--\nnet/nfc/netlink.c=572=static int nfc_genl_send_device(struct sk_buff *msg, struct nfc_dev *dev,\n--\nnet/nfc/netlink.c-578-\nnet/nfc/netlink.c:579:\thdr = genlmsg_put(msg, portid, seq, \u0026nfc_genl_family, flags,\nnet/nfc/netlink.c-580-\t\t\t  NFC_CMD_GET_DEVICE);\n--\nnet/nfc/netlink.c=652=int nfc_genl_dep_link_up_event(struct nfc_dev *dev, u32 target_idx,\n--\nnet/nfc/netlink.c-663-\nnet/nfc/netlink.c:664:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0, NFC_CMD_DEP_LINK_UP);\nnet/nfc/netlink.c-665-\tif (!hdr)\n--\nnet/nfc/netlink.c-680-\nnet/nfc/netlink.c:681:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_ATOMIC);\nnet/nfc/netlink.c-682-\n--\nnet/nfc/netlink.c=691=int nfc_genl_dep_link_down_event(struct nfc_dev *dev)\n--\nnet/nfc/netlink.c-701-\nnet/nfc/netlink.c:702:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-703-\t\t\t  NFC_CMD_DEP_LINK_DOWN);\n--\nnet/nfc/netlink.c-711-\nnet/nfc/netlink.c:712:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_ATOMIC);\nnet/nfc/netlink.c-713-\n--\nnet/nfc/netlink.c=992=static int nfc_genl_send_params(struct sk_buff *msg,\n--\nnet/nfc/netlink.c-997-\nnet/nfc/netlink.c:998:\thdr = genlmsg_put(msg, portid, seq, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-999-\t\t\t  NFC_CMD_LLC_GET_PARAMS);\n--\nnet/nfc/netlink.c=1254=int nfc_genl_fw_download_done(struct nfc_dev *dev, const char *firmware_name,\n--\nnet/nfc/netlink.c-1263-\nnet/nfc/netlink.c:1264:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-1265-\t\t\t  NFC_CMD_FW_DOWNLOAD);\n--\nnet/nfc/netlink.c-1275-\nnet/nfc/netlink.c:1276:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_ATOMIC);\nnet/nfc/netlink.c-1277-\n--\nnet/nfc/netlink.c=1332=static int nfc_genl_send_se(struct sk_buff *msg, struct nfc_dev *dev,\n--\nnet/nfc/netlink.c-1340-\tlist_for_each_entry_safe(se, n, \u0026dev-\u003esecure_elements, list) {\nnet/nfc/netlink.c:1341:\t\thdr = genlmsg_put(msg, portid, seq, \u0026nfc_genl_family, flags,\nnet/nfc/netlink.c-1342-\t\t\t\t  NFC_CMD_GET_SE);\n--\nnet/nfc/netlink.c=1472=static void se_io_cb(void *context, u8 *apdu, size_t apdu_len, int err)\n--\nnet/nfc/netlink.c-1483-\nnet/nfc/netlink.c:1484:\thdr = genlmsg_put(msg, 0, 0, \u0026nfc_genl_family, 0,\nnet/nfc/netlink.c-1485-\t\t\t  NFC_CMD_SE_IO);\n--\nnet/nfc/netlink.c-1495-\nnet/nfc/netlink.c:1496:\tgenlmsg_multicast(\u0026nfc_genl_family, msg, 0, 0, GFP_KERNEL);\nnet/nfc/netlink.c-1497-\n--\nnet/nfc/netlink.c=1620=static inline void *nfc_hdr_put(struct sk_buff *skb, u32 portid, u32 seq,\n--\nnet/nfc/netlink.c-1623-\t/* since there is no private header just add the generic one */\nnet/nfc/netlink.c:1624:\treturn genlmsg_put(skb, portid, seq, \u0026nfc_genl_family, flags, cmd);\nnet/nfc/netlink.c-1625-}\n--\nnet/nfc/netlink.c=1696=static const struct genl_ops nfc_genl_ops[] = {\n--\nnet/nfc/netlink.c-1813-\nnet/nfc/netlink.c:1814:static struct genl_family nfc_genl_family __ro_after_init = {\nnet/nfc/netlink.c-1815-\t.hdrsize = 0,\n--\nnet/nfc/netlink.c=1909=int __init nfc_genl_init(void)\n--\nnet/nfc/netlink.c-1912-\nnet/nfc/netlink.c:1913:\trc = genl_register_family(\u0026nfc_genl_family);\nnet/nfc/netlink.c-1914-\tif (rc)\n--\nnet/nfc/netlink.c=1927=void nfc_genl_exit(void)\n--\nnet/nfc/netlink.c-1929-\tnetlink_unregister_notifier(\u0026nl_notifier);\nnet/nfc/netlink.c:1930:\tgenl_unregister_family(\u0026nfc_genl_family);\nnet/nfc/netlink.c-1931-}\n"
}

gemini-3.8-flash

null

null

### 1. Approaches Tried and Their Results

1. **Inspected Patch Diff**:
   - Analyzed commit `923dbc502cd0d0256b3b662a960a0ed0c59bdd91` in `net/nfc/hci/command.c`.
   - Patch introduces two validation checks in `nfc_hci_create_pipe()`:
     - Checked response buffer length before accessing response data: `if (skb->len < sizeof(*resp)) { kfree_skb(skb); *result = -EPROTO; return NFC_HCI_INVALID_PIPE; }`.
     - Validated pipe index against upper bounds: `if (pipe >= NFC_HCI_MAX_PIPES) { *result = -EINVAL; return NFC_HCI_INVALID_PIPE; }`.

2. **Examined Surrounding Code in `net/nfc/hci/command.c`**:
   - Examined `nfc_hci_create_pipe()`, `nfc_hci_close_pipe()`, `nfc_hci_delete_pipe()`, and `nfc_hci_connect_gate()`.
   - In `nfc_hci_connect_gate()`, after pipe creation:
     ```c
     hdev->pipes[pipe].gate = dest_gate;
     hdev->pipes[pipe].dest_host = dest_host;
     hdev->gate2pipe[dest_gate] = pipe;
     ```
   - An unchecked `pipe >= NFC_HCI_MAX_PIPES` directly causes an out-of-bounds write to `hdev->pipes[pipe]`. Also, a short `skb` leads to an out-of-bounds read of `resp->pipe`.

3. **Investigated Callers and Reachability of `nfc_hci_create_pipe`**:
   - `nfc_hci_create_pipe` is static and called only by `nfc_hci_connect_gate()`.
   - `nfc_hci_connect_gate()` is called by:
     - `hci_dev_connect_gates()` in `net/nfc/hci/core.c`
     - `hci_dev_session_init()` in `net/nfc/hci/core.c` (during `hci_dev_up()`, triggered by `NFC_CMD_DEV_UP` via generic netlink `AF_NFC`)
     - Driver initializations in `drivers/nfc/st21nfca/core.c`.

4. **Investigated Devices/Drivers Allocating and Using `nfc_hci_dev`**:
   - Grepped `nfc_hci_allocate_device`:
     - `drivers/nfc/microread/microread.c` (buses: I2C `drivers/nfc/microread/i2c.c`, MEI `drivers/nfc/microread/mei.c`)
     - `drivers/nfc/pn544/pn544.c` (buses: I2C `drivers/nfc/pn544/i2c.c`, MEI `drivers/nfc/pn544/mei.c`)
     - `drivers/nfc/st21nfca/core.c` (bus: I2C `drivers/nfc/st21nfca/i2c.c`)
   - Checked virtual drivers (`virtual_ncidev.c`, `nfcsim.c`):
     - `virtual_ncidev.c` uses NCI (`nci_core.h`), not `net/nfc/hci/`.
     - `nfcsim.c` uses `nfc_digital_dev`, not `net/nfc/hci/`.
   - Checked USB NFC drivers (`drivers/nfc/nfcmrvl/usb.c`, `pn533/usb.c`, `port100.c`): none use `nfc_hci_dev`.
   - Checked `i2c-core-base.c`: I2C devices can be instantiated dynamically from userspace via `/sys/bus/i2c/devices/i2c-X/new_device` (e.g. `echo pn544 0x28 > /sys/bus/i2c/devices/i2c-0/new_device`).
   - However, `net/nfc/hci/` is a core network protocol layer within `net/nfc/` handling HCP (Host Controller Protocol) frames over SHDLC/LLC.

5. **Evaluated Fuzzing Triage Criteria**:
   - Modifies executable C logic in `net/nfc/hci/command.c`.
   - Core subsystem / network protocol layer (`net/nfc/hci/`).
   - Introduces defensive bounds checks and error handling preventing OOB read and OOB write vulnerabilities.
   - Code is not vendor-specific ASIC PCIe card code or driver `.remove` teardown path; it is part of `net/` protocol handling.
   - Meets Section 3 positive criteria: `WorthFuzzing=true`.

---

### 2. Hypotheses and Active Lines of Investigation

- **Decision**: `WorthFuzzing = true`.
- **Focus Symbols**:
  - `nfc_hci_create_pipe` (the specific static function modified in `net/nfc/hci/command.c`)
  - `nfc_hci_connect_gate` (direct non-static caller and subsystem entrypoint in `net/nfc/hci/command.c`)
  - `nfc_hci_hcp_message_rx` / `nfc_hci_resp_received` (response handling path delivering the response skb to waiting commands)
  - `hci_dev_session_init` / `hci_dev_up` (entrypoints exercising gate connection and pipe creation during device bringup)
- **EnableConfigs**:
  - `NFC` (parent config)
  - `NFC_HCI` (directly compiles `net/nfc/hci/command.c` and `hci.o`)
  - `NFC_SHDLC` (needed for SHDLC LLC frame handling in HCI)

---

### 3. Critical Code Snippets, Structs, and Configs

- **Modified function in `net/nfc/hci/command.c`**:
```c
static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
			      u8 dest_gate, int *result)
{
	struct sk_buff *skb;
	struct hci_create_pipe_params params;
	struct hci_create_pipe_resp *resp;
	u8 pipe;

	pr_debug("gate=%d\n", dest_gate);

	params.src_gate = NFC_HCI_ADMIN_GATE;
	params.dest_host = dest_host;
	params.dest_gate = dest_gate;

	*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
				      NFC_HCI_ADM_CREATE_PIPE,
				      (u8 *) &params, sizeof(params), &skb);
	if (*result < 0)
		return NFC_HCI_INVALID_PIPE;

	if (skb->len < sizeof(*resp)) {
		kfree_skb(skb);
		*result = -EPROTO;
		return NFC_HCI_INVALID_PIPE;
	}
	resp = (struct hci_create_pipe_resp *)skb->data;
	pipe = resp->pipe;
	kfree_skb(skb);

	if (pipe >= NFC_HCI_MAX_PIPES) {
		*result = -EINVAL;
		return NFC_HCI_INVALID_PIPE;
	}
	pr_debug("pipe created=%d\n", pipe);

	return pipe;
}
```

- **Kconfig in `net/nfc/hci/Kconfig` and `net/nfc/Makefile`**:
```makefile
obj-$(CONFIG_NFC_HCI) += hci/
```
```kconfig
config NFC_HCI
	depends on NFC
	tristate "NFC HCI implementation"

config NFC_SHDLC
	depends on NFC_HCI
	select CRC_CCITT
	bool "SHDLC link layer for HCI based NFC drivers"
```

---

### 4. Watchouts for Reasoning Loops

- Do not get sidetracked searching for virtual hardware or physical USB gadget devices: `net/nfc/hci/` is a network protocol stack layer under `net/`, not structurally unreachable vendor-specific PCIe switch/GPU ASIC code.
- Avoid listing ubiquitous lifecycle functions (`kfree_skb`, `memcpy`, etc.) in `FocusSymbols`.
- Only call `set-results` once before generating final output.

							input: 51566
							output: 2030
							thoughts: 0
						

gemini-3.8-flash

null

null

							input: 19278
							output: 38
							thoughts: 116
						

**Analyzing the NFC HCI Pipe Creation**

Okay, let's dive in. I need to understand the flow for creating an NFC HCI pipe. I know `nfc_hci_create_pipe` is defined within `net/nfc/hci/command.c`. My initial thought is to examine that specific function, and then determine all the call sites.

Right, I see that `nfc_hci_connect_gate` is a caller of `nfc_hci_create_pipe`. That's a key piece of the puzzle. Now I should probably zoom out and understand the context of the `nfc_hci_connect_gate` function itself. I will start by reviewing `net/nfc/hci/command.c` around the `nfc_hci_connect_gate` function.

{
  "File": "net/nfc/hci/command.c",
  "FirstLine": 220,
  "LineCount": 60
}

{
  "Contents": " 220:\t\tparams.dest_gate = dest_gate;\n 221:\t\n 222:\t\t*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\n 223:\t\t\t\t\t      NFC_HCI_ADM_CREATE_PIPE,\n 224:\t\t\t\t\t      (u8 *) \u0026params, sizeof(params), \u0026skb);\n 225:\t\tif (*result \u003c 0)\n 226:\t\t\treturn NFC_HCI_INVALID_PIPE;\n 227:\t\n 228:\t\tif (skb-\u003elen \u003c sizeof(*resp)) {\n 229:\t\t\tkfree_skb(skb);\n 230:\t\t\t*result = -EPROTO;\n 231:\t\t\treturn NFC_HCI_INVALID_PIPE;\n 232:\t\t}\n 233:\t\tresp = (struct hci_create_pipe_resp *)skb-\u003edata;\n 234:\t\tpipe = resp-\u003epipe;\n 235:\t\tkfree_skb(skb);\n 236:\t\n 237:\t\tif (pipe \u003e= NFC_HCI_MAX_PIPES) {\n 238:\t\t\t*result = -EINVAL;\n 239:\t\t\treturn NFC_HCI_INVALID_PIPE;\n 240:\t\t}\n 241:\t\tpr_debug(\"pipe created=%d\\n\", pipe);\n 242:\t\n 243:\t\treturn pipe;\n 244:\t}\n 245:\t\n 246:\tstatic int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)\n 247:\t{\n 248:\t\treturn nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\n 249:\t\t\t\t\t   NFC_HCI_ADM_DELETE_PIPE, \u0026pipe, 1, NULL);\n 250:\t}\n 251:\t\n 252:\tstatic int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)\n 253:\t{\n 254:\t\tu8 param[2];\n 255:\t\tsize_t param_len = 2;\n 256:\t\n 257:\t\t/* TODO: Find out what the identity reference data is\n 258:\t\t * and fill param with it. HCI spec 6.1.3.5 */\n 259:\t\n 260:\t\tif (test_bit(NFC_HCI_QUIRK_SHORT_CLEAR, \u0026hdev-\u003equirks))\n 261:\t\t\tparam_len = 0;\n 262:\t\n 263:\t\treturn nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\n 264:\t\t\t\t\t   NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,\n 265:\t\t\t\t\t   NULL);\n 266:\t}\n 267:\t\n 268:\tint nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)\n 269:\t{\n 270:\t\tint r;\n 271:\t\tu8 pipe = hdev-\u003egate2pipe[gate];\n 272:\t\n 273:\t\tif (pipe == NFC_HCI_INVALID_PIPE)\n 274:\t\t\treturn -EADDRNOTAVAIL;\n 275:\t\n 276:\t\tr = nfc_hci_close_pipe(hdev, pipe);\n 277:\t\tif (r \u003c 0)\n 278:\t\t\treturn r;\n 279:\t\n"
}

gemini-3.8-flash

null

null

							input: 20549
							output: 38
							thoughts: 19
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Diving into `net/nfc/hci/command.c`**

Okay, so I'm looking at `net/nfc/hci/command.c`. Time to refresh my memory on the command handling flow within the NFC HCI layer. I need to understand how commands are constructed, transmitted, and ultimately, processed at the lower layers. I'm especially interested in identifying potential bottlenecks or areas prone to errors. I'll be looking for things like buffer management strategies, command framing, error code handling, and any interaction with hardware specifics, as well as concurrency, and locking mechanisms. I'm going to pay close attention to the way the command parameters are constructed. I need to see what assumptions are made about their format and length, so I can think about potential vulnerabilities. Let's see... let's get started.

{
  "File": "net/nfc/hci/command.c",
  "FirstLine": 180,
  "LineCount": 45
}

{
  "Contents": " 180:\tEXPORT_SYMBOL(nfc_hci_get_param);\n 181:\t\n 182:\tstatic int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)\n 183:\t{\n 184:\t\tstruct sk_buff *skb;\n 185:\t\tint r;\n 186:\t\n 187:\t\tpr_debug(\"pipe=%d\\n\", pipe);\n 188:\t\n 189:\t\tr = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,\n 190:\t\t\t\t\tNULL, 0, \u0026skb);\n 191:\t\tif (r == 0) {\n 192:\t\t\t/* dest host other than host controller will send\n 193:\t\t\t * number of pipes already open on this gate before\n 194:\t\t\t * execution. The number can be found in skb-\u003edata[0]\n 195:\t\t\t */\n 196:\t\t\tkfree_skb(skb);\n 197:\t\t}\n 198:\t\n 199:\t\treturn r;\n 200:\t}\n 201:\t\n 202:\tstatic int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)\n 203:\t{\n 204:\t\treturn nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,\n 205:\t\t\t\t\t   NULL, 0, NULL);\n 206:\t}\n 207:\t\n 208:\tstatic u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,\n 209:\t\t\t\t      u8 dest_gate, int *result)\n 210:\t{\n 211:\t\tstruct sk_buff *skb;\n 212:\t\tstruct hci_create_pipe_params params;\n 213:\t\tstruct hci_create_pipe_resp *resp;\n 214:\t\tu8 pipe;\n 215:\t\n 216:\t\tpr_debug(\"gate=%d\\n\", dest_gate);\n 217:\t\n 218:\t\tparams.src_gate = NFC_HCI_ADMIN_GATE;\n 219:\t\tparams.dest_host = dest_host;\n 220:\t\tparams.dest_gate = dest_gate;\n 221:\t\n 222:\t\t*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\n 223:\t\t\t\t\t      NFC_HCI_ADM_CREATE_PIPE,\n 224:\t\t\t\t\t      (u8 *) \u0026params, sizeof(params), \u0026skb);\n"
}

gemini-3.8-flash

null

null

							input: 21522
							output: 38
							thoughts: 28
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Tracing `nfc_hci_connect_gate`**

Okay, so I'm trying to track down the implementation of `nfc_hci_connect_gate`. It's a standard function name, so I'm not immediately familiar with the specific callsite in this codebase. Based on my experience, and the context I have, I'm expecting this to be in the low-level HCI driver or connection management side of things, so I'll start by checking the lines around 280-350. This range is usually good place to start my quick search in this driver. That seems like a logical place to start digging, given the likely function of `nfc_hci_connect_gate`. Let's see what we find there. Hopefully, that'll give me the context I need to understand its role and how it's being used.

{
  "File": "net/nfc/hci/command.c",
  "FirstLine": 280,
  "LineCount": 50
}

{
  "Contents": " 280:\t\tif (pipe != NFC_HCI_LINK_MGMT_PIPE \u0026\u0026 pipe != NFC_HCI_ADMIN_PIPE) {\n 281:\t\t\tr = nfc_hci_delete_pipe(hdev, pipe);\n 282:\t\t\tif (r \u003c 0)\n 283:\t\t\t\treturn r;\n 284:\t\t}\n 285:\t\n 286:\t\thdev-\u003egate2pipe[gate] = NFC_HCI_INVALID_PIPE;\n 287:\t\n 288:\t\treturn 0;\n 289:\t}\n 290:\tEXPORT_SYMBOL(nfc_hci_disconnect_gate);\n 291:\t\n 292:\tint nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)\n 293:\t{\n 294:\t\tint r;\n 295:\t\n 296:\t\tr = nfc_hci_clear_all_pipes(hdev);\n 297:\t\tif (r \u003c 0)\n 298:\t\t\treturn r;\n 299:\t\n 300:\t\tnfc_hci_reset_pipes(hdev);\n 301:\t\n 302:\t\treturn 0;\n 303:\t}\n 304:\tEXPORT_SYMBOL(nfc_hci_disconnect_all_gates);\n 305:\t\n 306:\tint nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,\n 307:\t\t\t\t u8 pipe)\n 308:\t{\n 309:\t\tbool pipe_created = false;\n 310:\t\tint r;\n 311:\t\n 312:\t\tif (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)\n 313:\t\t\treturn 0;\n 314:\t\n 315:\t\tif (hdev-\u003egate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)\n 316:\t\t\treturn -EADDRINUSE;\n 317:\t\n 318:\t\tif (pipe != NFC_HCI_INVALID_PIPE)\n 319:\t\t\tgoto open_pipe;\n 320:\t\n 321:\t\tswitch (dest_gate) {\n 322:\t\tcase NFC_HCI_LINK_MGMT_GATE:\n 323:\t\t\tpipe = NFC_HCI_LINK_MGMT_PIPE;\n 324:\t\t\tbreak;\n 325:\t\tcase NFC_HCI_ADMIN_GATE:\n 326:\t\t\tpipe = NFC_HCI_ADMIN_PIPE;\n 327:\t\t\tbreak;\n 328:\t\tdefault:\n 329:\t\t\tpipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, \u0026r);\n"
}

gemini-3.8-flash

null

null

							input: 22531
							output: 38
							thoughts: 17
						

Okay, here's my attempt at summarizing the thought process, as requested, geared toward an expert audience, and written in the first person:

**Diving Deeper into `nfc_hci_connect_gate`**

Alright, so I'm looking at `nfc_hci_connect_gate` here. I need to get a better handle on the overall flow, specifically how it handles establishing the connection. My initial thought is to trace the execution from the entry point and understand the gate mechanism it's using. I'm assuming that it is using the same gate as other HCI commands, such as `nfc_hci_disconnect`, so I'll be focused on understanding if that is true and what it means for how this function interacts with the hardware, the tasklet or workqueue that it's connected with, and the underlying HCI layer.

I'm interested in the intricacies of how this function acquires whatever synchronization primitive it needs. Is it a mutex, a semaphore, a spinlock? What are the implications of the choice in a multi-threaded or interrupt-driven context? I need to understand if the chosen primitive might lead to contention, especially given the typically low-latency requirements of NFC interactions.

Furthermore, I have to be aware of how the function handles potential errors. What are the error codes, and where are they defined? Are there robust error-handling mechanisms in place? It would be interesting to see if any retry logic or failover mechanism is implemented, in case of intermittent connection failures. My experience tells me that these types of systems are prone to unexpected issues, especially given the wireless nature of the connection.

Finally, I'll be particularly interested in the eventual interaction with the hardware. Does it directly write to registers or go through some abstraction layer? I need to look for calls to the lower-level HCI functions that handle the actual hardware communication. And since these are, most likely, asynchronous, it should be clear what data structures are used for request/response tracking and, in case of an error, how the function cleans up any potential resources it might have allocated. My assumption is that the HCI layer uses a notification mechanism, probably an interrupt, but I'll have to see. It is essential to ensure that any allocated resources are properly managed in all code paths, whether success, failure, or unexpected conditions.

{
  "File": "net/nfc/hci/command.c",
  "FirstLine": 330,
  "LineCount": 40
}

{
  "Contents": " 330:\t\t\tif (pipe == NFC_HCI_INVALID_PIPE)\n 331:\t\t\t\treturn r;\n 332:\t\t\tpipe_created = true;\n 333:\t\t\tbreak;\n 334:\t\t}\n 335:\t\n 336:\topen_pipe:\n 337:\t\tr = nfc_hci_open_pipe(hdev, pipe);\n 338:\t\tif (r \u003c 0) {\n 339:\t\t\tif (pipe_created)\n 340:\t\t\t\tif (nfc_hci_delete_pipe(hdev, pipe) \u003c 0) {\n 341:\t\t\t\t\t/* TODO: Cannot clean by deleting pipe...\n 342:\t\t\t\t\t * -\u003e inconsistent state */\n 343:\t\t\t\t}\n 344:\t\t\treturn r;\n 345:\t\t}\n 346:\t\n 347:\t\thdev-\u003epipes[pipe].gate = dest_gate;\n 348:\t\thdev-\u003epipes[pipe].dest_host = dest_host;\n 349:\t\thdev-\u003egate2pipe[dest_gate] = pipe;\n 350:\t\n 351:\t\treturn 0;\n 352:\t}\n 353:\tEXPORT_SYMBOL(nfc_hci_connect_gate);\n"
}

gemini-3.8-flash

null

null

							input: 23412
							output: 32
							thoughts: 359
						

**My Analysis of a Potential Vulnerability in NFC Pipe Creation**

Okay, let's break this down. My initial thought is that if that crucial size check on `skb->len` is missing, we've got a potential serious problem. Specifically, the following scenario comes to mind:

Without the check `if (skb->len < sizeof(*resp))`, if the received socket buffer, `skb`, is too small, reading `resp->pipe` could lead to an out-of-bounds read or, even worse, reading uninitialized memory. That's immediately concerning from a security perspective. And we can assume the data from this socket buffer is untrusted.

Even if `skb->len` *is* big enough, the subsequent `pipe` assignment and validation can be bypassed. So, if the crafted `pipe` value, let's say a value larger than or equal to `NFC_HCI_MAX_PIPES` *but not* `NFC_HCI_INVALID_PIPE`, manages to get past that check, we're really in trouble.

If `pipe` is too large, the vulnerable code then calls `nfc_hci_open_pipe(hdev, pipe)`. This function might succeed or fail, doesn't matter. The real kicker is the next line: `hdev->pipes[pipe].gate = dest_gate;`. Here's where we get the out-of-bounds write. Since `hdev->pipes` is an array of size `NFC_HCI_MAX_PIPES`, indexing with a value like `150` (assuming `NFC_HCI_MAX_PIPES` is say 128) will smash memory outside the bounds of the allocated array. That's an obvious vulnerability.

Now, how does this relate to what I'm doing? I need to figure out how syzkaller might be able to trigger this. I'll need to look for some NFC descriptions in the syzkaller corpus. Alternatively, I need to check whether generic netlink or plain socket usage can reach this code path. I'll start by searching the `net/nfc/` directory for commands like `NFC_CMD_DEV_UP` and anything else that looks promising. This all feels like a good lead. Let's dig in.

{
  "Expression": "NFC_CMD_DEV_UP",
  "PathPrefix": "net/nfc"
}

{
  "Output": "net/nfc/netlink.c=1696=static const struct genl_ops nfc_genl_ops[] = {\n--\nnet/nfc/netlink.c-1704-\t{\nnet/nfc/netlink.c:1705:\t\t.cmd = NFC_CMD_DEV_UP,\nnet/nfc/netlink.c-1706-\t\t.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,\n"
}

gemini-3.8-flash

null

null

							input: 24438
							output: 38
							thoughts: 36
						

Here's my thinking:

**Deconstructing the NFC Command Flow**

Okay, so I'm trying to trace the execution path of `NFC_CMD_DEV_UP`. I know it's a netlink command, so the logical starting point is the `netlink.c` file. Specifically, I'm expecting the function call to be handled somewhere around line 1705. Let's get cracking, pull up that file and that line and see what we can find. I expect it is calling some function to bring up the device. This is the only way to quickly pinpoint what happens when the device has to be brought up.

{
  "File": "net/nfc/netlink.c",
  "FirstLine": 1700,
  "LineCount": 25
}

{
  "Contents": "1700:\t\t\t.doit = nfc_genl_get_device,\n1701:\t\t\t.dumpit = nfc_genl_dump_devices,\n1702:\t\t\t.done = nfc_genl_dump_devices_done,\n1703:\t\t},\n1704:\t\t{\n1705:\t\t\t.cmd = NFC_CMD_DEV_UP,\n1706:\t\t\t.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,\n1707:\t\t\t.doit = nfc_genl_dev_up,\n1708:\t\t\t.flags = GENL_ADMIN_PERM,\n1709:\t\t},\n1710:\t\t{\n1711:\t\t\t.cmd = NFC_CMD_DEV_DOWN,\n1712:\t\t\t.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,\n1713:\t\t\t.doit = nfc_genl_dev_down,\n1714:\t\t\t.flags = GENL_ADMIN_PERM,\n1715:\t\t},\n1716:\t\t{\n1717:\t\t\t.cmd = NFC_CMD_START_POLL,\n1718:\t\t\t.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,\n1719:\t\t\t.doit = nfc_genl_start_poll,\n1720:\t\t\t.flags = GENL_ADMIN_PERM,\n1721:\t\t},\n1722:\t\t{\n1723:\t\t\t.cmd = NFC_CMD_STOP_POLL,\n1724:\t\t\t.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,\n"
}

gemini-3.8-flash

null

null

							input: 25110
							output: 33
							thoughts: 15
						

Okay, let's break this down.

**Analyzing `nfc_genl_dev_up`**

Alright, so the task at hand seems to involve `nfc_genl_dev_up`. My initial thought is to immediately recognize this as likely referring to the Generic Netlink (genl) interface within the Near Field Communication (NFC) subsystem. Given my expertise, I already know this is a critical function for bringing an NFC device online and making it available for communication. The "up" suffix strongly suggests this is the routine that handles initialization, setup, and device enablement, probably in response to a request from userspace. It will be interesting to dissect the underlying implementations and discover what specific actions are performed within that `genl` context. I expect this would involve things such as: registration of the device, allocation of resources, enabling of the NFC controller hardware, establishing communication channels, and possibly binding with relevant driver layers. I'm keen to see the implementation details.

{
  "Expression": "nfc_genl_dev_up",
  "PathPrefix": "net/nfc"
}

{
  "Output": "net/nfc/netlink.c=722=static int nfc_genl_get_device(struct sk_buff *skb, struct genl_info *info)\n--\nnet/nfc/netlink.c-759-\nnet/nfc/netlink.c:760:static int nfc_genl_dev_up(struct sk_buff *skb, struct genl_info *info)\nnet/nfc/netlink.c-761-{\n--\nnet/nfc/netlink.c=1696=static const struct genl_ops nfc_genl_ops[] = {\n--\nnet/nfc/netlink.c-1706-\t\t.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,\nnet/nfc/netlink.c:1707:\t\t.doit = nfc_genl_dev_up,\nnet/nfc/netlink.c-1708-\t\t.flags = GENL_ADMIN_PERM,\n"
}

gemini-3.8-flash

null

null

							input: 25632
							output: 37
							thoughts: 27
						

Here's my take on those thoughts, tailored for an expert audience:

**Diving into the NFC Netlink Driver**

Okay, so I'm thinking about `nfc_genl_dev_up`.  That's in `net/nfc/netlink.c`, which tells me we're looking at the netlink interface for NFC device management. I need to refresh my memory on the up/down state transition for the NFC device. I need to understand how the NFC device is brought up through netlink. Is this the right entrypoint for the device? What are the implications of bringing up the device through netlink and the various associated interactions? And what are the implications of the state transitions?

{
  "File": "net/nfc/netlink.c",
  "FirstLine": 760,
  "LineCount": 30
}

{
  "Contents": " 760:\tstatic int nfc_genl_dev_up(struct sk_buff *skb, struct genl_info *info)\n 761:\t{\n 762:\t\tstruct nfc_dev *dev;\n 763:\t\tint rc;\n 764:\t\tu32 idx;\n 765:\t\n 766:\t\tif (!info-\u003eattrs[NFC_ATTR_DEVICE_INDEX])\n 767:\t\t\treturn -EINVAL;\n 768:\t\n 769:\t\tidx = nla_get_u32(info-\u003eattrs[NFC_ATTR_DEVICE_INDEX]);\n 770:\t\n 771:\t\tdev = nfc_get_device(idx);\n 772:\t\tif (!dev)\n 773:\t\t\treturn -ENODEV;\n 774:\t\n 775:\t\trc = nfc_dev_up(dev);\n 776:\t\n 777:\t\tnfc_put_device(dev);\n 778:\t\treturn rc;\n 779:\t}\n 780:\t\n 781:\tstatic int nfc_genl_dev_down(struct sk_buff *skb, struct genl_info *info)\n 782:\t{\n 783:\t\tstruct nfc_dev *dev;\n 784:\t\tint rc;\n 785:\t\tu32 idx;\n 786:\t\n 787:\t\tif (!info-\u003eattrs[NFC_ATTR_DEVICE_INDEX])\n 788:\t\t\treturn -EINVAL;\n 789:\t\n"
}

gemini-3.8-flash

null

null

							input: 26269
							output: 31
							thoughts: 25
						

Okay, let's dive into this. I'm looking at `nfc_dev_up(dev)` within `net/nfc/core.c`. My initial thought is to understand the context of this function. I know this is related to NFC, but "dev" is generic, so what kind of NFC device are we dealing with here? I need to quickly recall the typical initialization sequence within this module. What steps are involved in bringing an NFC device online? Are we talking about hardware initialization, driver probing, resource allocation, or a combination of these? Where does it fit into the larger picture of the NFC stack? I need to understand how this function is *called* to fully grasp its purpose. Is it triggered by a user-space request, a hardware interrupt, or some internal scheduling event? What are the potential error paths? More specifically, what are the possible return values from `nfc_dev_up` and what do they mean in terms of recovery or failure scenarios? I need to start tracing through the code to identify the key data structures used and updated here, especially the `dev` structure that is passed in. Are there any locks involved? How are potential race conditions handled, given the likely asynchronous nature of NFC operations? I need to verify that this function aligns with the broader architecture and the expected behavior of the system. I also need to be aware of how this impacts power management in the driver, so I'll also be mindful of that.

{
  "Expression": "int nfc_dev_up",
  "PathPrefix": "net/nfc"
}

{
  "Output": "net/nfc/core.c=80=EXPORT_SYMBOL(nfc_fw_download_done);\n--\nnet/nfc/core.c-88- */\nnet/nfc/core.c:89:int nfc_dev_up(struct nfc_dev *dev)\nnet/nfc/core.c-90-{\n--\nnet/nfc/nfc.h=126=int nfc_genl_fw_download_done(struct nfc_dev *dev, const char *firmware_name,\n--\nnet/nfc/nfc.h-128-\nnet/nfc/nfc.h:129:int nfc_dev_up(struct nfc_dev *dev);\nnet/nfc/nfc.h-130-\n"
}

gemini-3.8-flash

null

null

							input: 26834
							output: 35
							thoughts: 23
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Diving into `nfc_dev_up`**

Okay, so I'm digging into the NFC stack, and the first place I'm going to check out is `nfc_dev_up`. I know that's defined in `net/nfc/core.c`, so that's where I'll be starting. I'm assuming this function is central to bringing an NFC device online, likely handling all the initial setup and configuration tasks required for the device to be usable within the kernel's NFC framework. I'm expecting to see things like resource allocation, hardware initialization (maybe even probing if it's not done elsewhere), and potentially registering the device with the core NFC subsystem. I'll need to pay close attention to the error handling within this function, as any failures here could lead to cascading problems down the line. I'll be looking for how it interacts with the underlying hardware drivers and any associated power management routines. It's the critical first step, so I'm keen to understand the sequence of actions and any locking mechanisms used to ensure a clean and thread-safe initialization process. This is the lynchpin – the entry point for device activation, I bet.

{
  "File": "net/nfc/core.c",
  "FirstLine": 89,
  "LineCount": 35
}

{
  "Contents": "  89:\tint nfc_dev_up(struct nfc_dev *dev)\n  90:\t{\n  91:\t\tint rc = 0;\n  92:\t\n  93:\t\tpr_debug(\"dev_name=%s\\n\", dev_name(\u0026dev-\u003edev));\n  94:\t\n  95:\t\tdevice_lock(\u0026dev-\u003edev);\n  96:\t\n  97:\t\tif (dev-\u003eshutting_down) {\n  98:\t\t\trc = -ENODEV;\n  99:\t\t\tgoto error;\n 100:\t\t}\n 101:\t\n 102:\t\tif (dev-\u003erfkill \u0026\u0026 rfkill_blocked(dev-\u003erfkill)) {\n 103:\t\t\trc = -ERFKILL;\n 104:\t\t\tgoto error;\n 105:\t\t}\n 106:\t\n 107:\t\tif (dev-\u003efw_download_in_progress) {\n 108:\t\t\trc = -EBUSY;\n 109:\t\t\tgoto error;\n 110:\t\t}\n 111:\t\n 112:\t\tif (dev-\u003edev_up) {\n 113:\t\t\trc = -EALREADY;\n 114:\t\t\tgoto error;\n 115:\t\t}\n 116:\t\n 117:\t\tif (dev-\u003eops-\u003edev_up)\n 118:\t\t\trc = dev-\u003eops-\u003edev_up(dev);\n 119:\t\n 120:\t\tif (!rc)\n 121:\t\t\tdev-\u003edev_up = true;\n 122:\t\n 123:\t\t/* We have to enable the device before discovering SEs */\n"
}

gemini-3.8-flash

null

null

							input: 27600
							output: 29
							thoughts: 43
						

Okay, here's my interpretation of those thoughts, framed as if they are my own:

**Delving into HCI Device Initialization**

Alright, let's see, I'm working with these HCI devices, and I'm encountering `dev->ops->dev_up`. I recognize it's probably a crucial function within the operational structure. My immediate question is, precisely *what* does this do in the context of Human-Computer Interaction? It's the `dev_up` operation, so it must be critical for bringing the device online.

To gain a clearer understanding of its usage and what it depends on, I'll need some context. Let's delve into the NFC HCI code specifically. I'll search the `net/nfc/hci/` directory for `nfc_hci_allocate_device`. That allocation function is likely an important point of entry, where device structure `dev->ops->dev_up` would be assigned. I'm sure finding where the device allocation happens will provide insight to the role of `dev_up`. This should provide me with the initial setup and initialization steps that precede the point where `dev->ops->dev_up` would be called. Then, I can analyze how the driver interacts with the underlying hardware, how resources are allocated, and ultimately, how `dev_up` fits into the device lifecycle. Let's get to it.

{
  "Expression": "dev_up",
  "PathPrefix": "net/nfc/hci"
}

{
  "Output": "net/nfc/hci/core.c=520=static int hci_dev_version(struct nfc_hci_dev *hdev)\n--\nnet/nfc/hci/core.c-578-\nnet/nfc/hci/core.c:579:static int hci_dev_up(struct nfc_dev *nfc_dev)\nnet/nfc/hci/core.c-580-{\n--\nnet/nfc/hci/core.c=941=static const struct nfc_ops hci_nfc_ops = {\nnet/nfc/hci/core.c:942:\t.dev_up = hci_dev_up,\nnet/nfc/hci/core.c-943-\t.dev_down = hci_dev_down,\n"
}

gemini-3.8-flash

null

null

							input: 28172
							output: 38
							thoughts: 47
						

Here's a breakdown of my thought process, focusing on what I'd be looking for in that specific section of the NFC HCI core code:

**Diving into `hci_dev_up`**

Okay, `hci_dev_up` in `net/nfc/hci/core.c`.  Right away, my mind jumps to initialization and bringing a new NFC HCI device online. This function is *critical* in establishing the device's operational state within the kernel. My immediate focus will be on lines 570-650 – that's where the core of the operation likely lies.

I'm expecting to see things like:

*   **Resource Allocation:**  Is there memory being allocated for the device's internal structures?  Are buffers being set up for communication? I'll be looking for `kmalloc`, `kzalloc`, or similar allocation functions. I need to understand what resources the system is dedicating to this new device.
*   **Hardware Initialization:**  How is the hardware being configured? Are there register writes to set up the NFC controller's clocks, power, interrupt lines, and communication parameters? I'll be scanning for any function calls related to setting up the hardware, or interacting directly with device registers. This is where the hardware specific details may lie, which are important when developing on a new platform.
*   **State Transitions:** How is the device state being handled? Is there a state machine involved? I'll be looking for how the system handles the transition from a "down" or "initializing" state to an "up" or "operational" state. I need to find the specific state changes and how they are handled.
*   **Interrupt Handling:** Is the interrupt being properly enabled and configured?  I'll want to see how the system handles the asynchronous nature of NFC communication.
*   **Error Handling:** What's the error checking like?  Is there proper error detection and handling in the event of hardware failures or initialization problems? Robustness is key, so I'll be looking for checks on return codes and how the system responds to failures.
*   **Driver Specific Functions:** Are there any driver-specific functions being called during this process? If so, I'll need to follow the links to understand the device specific behaviour.

Basically, I'm expecting a critical chunk of code that's the "engine" that kicks the NFC HCI device into gear.  My goal is to understand the full sequence of events that bring the device to life, and how this particular driver handles the transition.

{
  "File": "net/nfc/hci/core.c",
  "FirstLine": 575,
  "LineCount": 55
}

{
  "Contents": " 575:\t\n 576:\t\treturn 0;\n 577:\t}\n 578:\t\n 579:\tstatic int hci_dev_up(struct nfc_dev *nfc_dev)\n 580:\t{\n 581:\t\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\n 582:\t\tint r = 0;\n 583:\t\n 584:\t\tif (hdev-\u003eops-\u003eopen) {\n 585:\t\t\tr = hdev-\u003eops-\u003eopen(hdev);\n 586:\t\t\tif (r \u003c 0)\n 587:\t\t\t\treturn r;\n 588:\t\t}\n 589:\t\n 590:\t\tr = nfc_llc_start(hdev-\u003ellc);\n 591:\t\tif (r \u003c 0)\n 592:\t\t\tgoto exit_close;\n 593:\t\n 594:\t\tr = hci_dev_session_init(hdev);\n 595:\t\tif (r \u003c 0)\n 596:\t\t\tgoto exit_llc;\n 597:\t\n 598:\t\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\n 599:\t\t\t\t       NFC_HCI_EVT_END_OPERATION, NULL, 0);\n 600:\t\tif (r \u003c 0)\n 601:\t\t\tgoto exit_llc;\n 602:\t\n 603:\t\tif (hdev-\u003eops-\u003ehci_ready) {\n 604:\t\t\tr = hdev-\u003eops-\u003ehci_ready(hdev);\n 605:\t\t\tif (r \u003c 0)\n 606:\t\t\t\tgoto exit_llc;\n 607:\t\t}\n 608:\t\n 609:\t\tr = hci_dev_version(hdev);\n 610:\t\tif (r \u003c 0)\n 611:\t\t\tgoto exit_llc;\n 612:\t\n 613:\t\treturn 0;\n 614:\t\n 615:\texit_llc:\n 616:\t\tnfc_llc_stop(hdev-\u003ellc);\n 617:\t\n 618:\texit_close:\n 619:\t\tif (hdev-\u003eops-\u003eclose)\n 620:\t\t\thdev-\u003eops-\u003eclose(hdev);\n 621:\t\n 622:\t\treturn r;\n 623:\t}\n 624:\t\n 625:\tstatic int hci_dev_down(struct nfc_dev *nfc_dev)\n 626:\t{\n 627:\t\tstruct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);\n 628:\t\n 629:\t\tnfc_llc_stop(hdev-\u003ellc);\n"
}

gemini-3.8-flash

null

null

							input: 29568
							output: 38
							thoughts: 29
						

Okay, here's my interpretation of that thought process, from an expert's perspective:

**Diving into the NFC HCI Driver Initialization**

Alright, my internal radar just pinged on `hci_dev_session_init(hdev)`.  That function call, found within `net/nfc/hci/core.c`, is likely the very starting point of an NFC HCI device's life. I immediately recognize this as where the NFC Host Controller Interface (HCI) device session gets set up. This is usually the stage before device registration with NFC, I will need to check how the HCI device, `hdev` is initialized or set up. It’s the kernel's way of setting the stage to allow communication between the host controller and the NFC hardware. This `hci_dev_session_init` function is where the core logic resides, and I should expect to find important setup details such as registering any necessary callbacks, allocating session-specific resources, and initializing any internal data structures related to the NFC HCI device. I'll need to understand how the NFC HCI protocol stacks, HCI commands and events processing occurs. A deeper look at this `net/nfc/hci/core.c` file should give me a good sense of how the overall HCI framework is built, and what layers it depends on. Given my expertise, I suspect this function might be more complex than it looks, probably handling various potential error conditions and device initialization pitfalls, along with potential device capabilities detection. I'll need to quickly understand the control flow.

{
  "File": "net/nfc/hci/core.c",
  "FirstLine": 435,
  "LineCount": 55
}

{
  "Contents": " 435:\t\tkfree_skb(skb);\n 436:\t\n 437:\texit_noskb:\n 438:\t\tif (r)\n 439:\t\t\tnfc_hci_driver_failure(hdev, r);\n 440:\t}\n 441:\t\n 442:\tstatic void nfc_hci_cmd_timeout(struct timer_list *t)\n 443:\t{\n 444:\t\tstruct nfc_hci_dev *hdev = timer_container_of(hdev, t, cmd_timer);\n 445:\t\n 446:\t\tschedule_work(\u0026hdev-\u003emsg_tx_work);\n 447:\t}\n 448:\t\n 449:\tstatic int hci_dev_connect_gates(struct nfc_hci_dev *hdev, u8 gate_count,\n 450:\t\t\t\t\t const struct nfc_hci_gate *gates)\n 451:\t{\n 452:\t\tint r;\n 453:\t\twhile (gate_count--) {\n 454:\t\t\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\n 455:\t\t\t\t\t\t gates-\u003egate, gates-\u003epipe);\n 456:\t\t\tif (r \u003c 0)\n 457:\t\t\t\treturn r;\n 458:\t\t\tgates++;\n 459:\t\t}\n 460:\t\n 461:\t\treturn 0;\n 462:\t}\n 463:\t\n 464:\tstatic int hci_dev_session_init(struct nfc_hci_dev *hdev)\n 465:\t{\n 466:\t\tstruct sk_buff *skb = NULL;\n 467:\t\tint r;\n 468:\t\n 469:\t\tif (hdev-\u003einit_data.gates[0].gate != NFC_HCI_ADMIN_GATE)\n 470:\t\t\treturn -EPROTO;\n 471:\t\n 472:\t\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\n 473:\t\t\t\t\t hdev-\u003einit_data.gates[0].gate,\n 474:\t\t\t\t\t hdev-\u003einit_data.gates[0].pipe);\n 475:\t\tif (r \u003c 0)\n 476:\t\t\tgoto exit;\n 477:\t\n 478:\t\tr = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,\n 479:\t\t\t\t      NFC_HCI_ADMIN_SESSION_IDENTITY, \u0026skb);\n 480:\t\tif (r \u003c 0)\n 481:\t\t\tgoto disconnect_all;\n 482:\t\n 483:\t\tif (skb-\u003elen \u0026\u0026 skb-\u003elen == strlen(hdev-\u003einit_data.session_id) \u0026\u0026\n 484:\t\t\t(memcmp(hdev-\u003einit_data.session_id, skb-\u003edata,\n 485:\t\t\t\t   skb-\u003elen) == 0) \u0026\u0026 hdev-\u003eops-\u003eload_session) {\n 486:\t\t\t/* Restore gate\u003c-\u003epipe table from some proprietary location. */\n 487:\t\n 488:\t\t\tr = hdev-\u003eops-\u003eload_session(hdev);\n 489:\t\n"
}

gemini-3.8-flash

null

null

							input: 30820
							output: 38
							thoughts: 11
						

Okay, I'm ready. Let's dive into these lines and get this summary tailored for an expert's mind.

**Analyzing the Core Arguments and Implications**

Alright, looking at lines 490-520, I see the core argument is taking shape. It seems to be building towards a key point, a pivot perhaps, in the established line of reasoning. The initial setup probably established some groundwork – definitions, context, maybe even prior research. Now, it appears we're moving toward something more critical: either a direct counterargument, a new avenue for investigation, or a conclusive finding that rests upon the foundations we've built. My immediate assessment? This section likely focuses on how previous conclusions could be incomplete or even flawed, thus necessitating a re-evaluation of the data or methodology. I suspect a nuanced discussion on the limitations of the current paradigm will likely lead to the exploration of some new assumptions. The strength of the counter, if it is a counter, is the most crucial aspect of the lines. Whether it’s an incremental improvement or a groundbreaking discovery remains to be seen. I need to pay close attention to the evidence presented here because this is where the meat of the argument is likely to be. Ultimately, I will evaluate the strength of the proposed change relative to the context. My mind immediately begins to formulate how this would be received in the field.

{
  "File": "net/nfc/hci/core.c",
  "FirstLine": 490,
  "LineCount": 35
}

{
  "Contents": " 490:\t\t\tif (r \u003c 0)\n 491:\t\t\t\tgoto disconnect_all;\n 492:\t\t} else {\n 493:\t\n 494:\t\t\tr = nfc_hci_disconnect_all_gates(hdev);\n 495:\t\t\tif (r \u003c 0)\n 496:\t\t\t\tgoto exit;\n 497:\t\n 498:\t\t\tr = hci_dev_connect_gates(hdev, hdev-\u003einit_data.gate_count,\n 499:\t\t\t\t\t\t  hdev-\u003einit_data.gates);\n 500:\t\t\tif (r \u003c 0)\n 501:\t\t\t\tgoto disconnect_all;\n 502:\t\n 503:\t\t\tr = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,\n 504:\t\t\t\t\tNFC_HCI_ADMIN_SESSION_IDENTITY,\n 505:\t\t\t\t\thdev-\u003einit_data.session_id,\n 506:\t\t\t\t\tstrlen(hdev-\u003einit_data.session_id));\n 507:\t\t}\n 508:\t\tif (r == 0)\n 509:\t\t\tgoto exit;\n 510:\t\n 511:\tdisconnect_all:\n 512:\t\tnfc_hci_disconnect_all_gates(hdev);\n 513:\t\n 514:\texit:\n 515:\t\tkfree_skb(skb);\n 516:\t\n 517:\t\treturn r;\n 518:\t}\n 519:\t\n 520:\tstatic int hci_dev_version(struct nfc_hci_dev *hdev)\n 521:\t{\n 522:\t\tint r;\n 523:\t\tstruct sk_buff *skb;\n 524:\t\n"
}

gemini-3.8-flash

null

null

							input: 31632
							output: 34
							thoughts: 112
						

**My Analysis of the HCI Connection Flow**

Okay, so I'm digging into the HCI connection process and it looks like `hci_dev_connect_gates()` is the key function. It's iterating through the drivers' gates and calling `nfc_hci_connect_gate()` for each one. That makes sense, a standard way to establish multiple connections.

Now, within `nfc_hci_connect_gate`, the crucial part seems to be handling the pipe setup. If the gate pipe is invalid, or if it needs to be created from scratch, then `nfc_hci_create_pipe` is triggered. This is where the low-level communication is likely established.

Finally, I need to understand how responses are handled. I need to trace where the HCP responses are actually received. I'm going to follow the processing of `nfc_hci_resp_received` or `nfc_hci_hcp_message_rx` to see the complete picture. This should show me the entire data flow through the device.

{
  "Expression": "nfc_hci_resp_received",
  "PathPrefix": "net/nfc/hci"
}

{
  "Output": "net/nfc/hci/core.c=148=static void __nfc_hci_cmd_completion(struct nfc_hci_dev *hdev, int err,\n--\nnet/nfc/hci/core.c-164-\nnet/nfc/hci/core.c:165:void nfc_hci_resp_received(struct nfc_hci_dev *hdev, u8 result,\nnet/nfc/hci/core.c-166-\t\t\t   struct sk_buff *skb)\n--\nnet/nfc/hci/hcp.c=117=void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,\n--\nnet/nfc/hci/hcp.c-121-\tcase NFC_HCI_HCP_RESPONSE:\nnet/nfc/hci/hcp.c:122:\t\tnfc_hci_resp_received(hdev, instruction, skb);\nnet/nfc/hci/hcp.c-123-\t\tbreak;\n"
}

gemini-3.8-flash

null

null

							input: 32275
							output: 27
							thoughts: 301
						

**Analyzing the NFC HCI Pipe Creation**

Okay, let's break this down. So, `nfc_hci_resp_received` hands off the received `skb` – that's the *socket buffer* – to `hdev->cmd_response` and subsequently signals `hdev->cmd_complete`. Right, then `nfc_hci_execute_cmd` passes that very `skb` back.

The next critical step, in `nfc_hci_create_pipe`, is where it interprets the data within the `skb` as a `hci_create_pipe_resp` structure. Now, the code checks the `skb->len` to ensure it's at least as large as the `hci_create_pipe_resp` structure size. If it's *smaller*, the `skb` gets freed and we return an error, returning `NFC_HCI_INVALID_PIPE`. This is all to prevent a read or write violation. If it's large enough, it casts the beginning of the skb as a pointer to the structure, gets the pipe value, frees the skb, and verifies the pipe value, returning the result.

This is a pretty classic vulnerability: a bad actor sending bad data over the NFC controller could potentially trigger an out-of-bounds read and write here, if the length check wasn't there. It looks like we're handling that correctly now, but it's always worth a double-check.

Now, I'm going to quickly glance at the Kconfig options for `net/nfc/hci/command.c` to see how it's being compiled. Gotta make sure the relevant bits are enabled. Then, I'll take a look at `net/nfc/hci/Makefile` and then `net/nfc/Makefile` to understand the build dependencies. This gives more context for other possible issues.

{
  "Expression": "command.o",
  "PathPrefix": "net/nfc"
}

{
  "Output": "net/nfc/hci/Makefile=6=obj-$(CONFIG_NFC_HCI) += hci.o\nnet/nfc/hci/Makefile-7-\nnet/nfc/hci/Makefile:8:hci-y\t\t\t:= core.o hcp.o command.o llc.o llc_nop.o\nnet/nfc/hci/Makefile-9-hci-$(CONFIG_NFC_SHDLC) += llc_shdlc.o\n"
}

gemini-3.8-flash

null

null

							input: 33126
							output: 29
							thoughts: 12
						

Here's my take on those thoughts:

**Analyzing the `net/nfc/Makefile`**

Okay, time to dive into the `net/nfc/Makefile`. I need to understand what's going on with the NFC stack build. This is the central point for controlling how the NFC kernel modules are built, linked, and included. I'm going to quickly scan it to grasp the overall structure. I'll pay close attention to any conditional logic, especially around kernel version checks, Kconfig options, and target-specific configurations, as these are critical for understanding portability and feature enablement. I'm also looking for dependencies – what other Makefiles or source files are included, and what libraries are linked? Knowing this will help identify any potential conflicts or areas that need modification for my specific platform. Ultimately, I'm aiming to gain a solid grasp of this Makefile's role in the larger kernel build process and identify any areas that might affect my area of work.

{
  "Expression": "NFC_HCI",
  "PathPrefix": "net/nfc"
}

{
  "Output": "net/nfc/Makefile=7=obj-$(CONFIG_NFC_NCI) += nci/\nnet/nfc/Makefile:8:obj-$(CONFIG_NFC_HCI) += hci/\nnet/nfc/Makefile-9-obj-$(CONFIG_NFC_DIGITAL) += nfc_digital.o\n--\nnet/nfc/hci/Kconfig-1-# SPDX-License-Identifier: GPL-2.0-only\nnet/nfc/hci/Kconfig:2:config NFC_HCI\nnet/nfc/hci/Kconfig-3-\tdepends on NFC\n--\nnet/nfc/hci/Kconfig=11=config NFC_SHDLC\nnet/nfc/hci/Kconfig:12:\tdepends on NFC_HCI\nnet/nfc/hci/Kconfig-13-\tselect CRC_CCITT\n--\nnet/nfc/hci/Makefile-5-\nnet/nfc/hci/Makefile:6:obj-$(CONFIG_NFC_HCI) += hci.o\nnet/nfc/hci/Makefile-7-\n--\nnet/nfc/hci/command.c=19=static int nfc_hci_execute_cmd_async(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,\n--\nnet/nfc/hci/command.c-28-\t */\nnet/nfc/hci/command.c:29:\treturn nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_COMMAND, cmd,\nnet/nfc/hci/command.c-30-\t\t\t\t      param, param_len, cb, cb_context, MAX_FWI);\n--\nnet/nfc/hci/command.c=55=static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,\n--\nnet/nfc/hci/command.c-71-\thcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,\nnet/nfc/hci/command.c:72:\t\t\t\t\t\t    NFC_HCI_HCP_COMMAND, cmd,\nnet/nfc/hci/command.c-73-\t\t\t\t\t\t    param, param_len,\n--\nnet/nfc/hci/command.c=91=int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,\n--\nnet/nfc/hci/command.c-98-\tpipe = hdev-\u003egate2pipe[gate];\nnet/nfc/hci/command.c:99:\tif (pipe == NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-100-\t\treturn -EADDRNOTAVAIL;\nnet/nfc/hci/command.c-101-\nnet/nfc/hci/command.c:102:\treturn nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,\nnet/nfc/hci/command.c-103-\t\t\t\t      param, param_len, NULL, NULL, 0);\n--\nnet/nfc/hci/command.c=112=int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,\n--\nnet/nfc/hci/command.c-117-\tpipe = hdev-\u003egate2pipe[gate];\nnet/nfc/hci/command.c:118:\tif (pipe == NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-119-\t\treturn -EADDRNOTAVAIL;\n--\nnet/nfc/hci/command.c=125=int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,\n--\nnet/nfc/hci/command.c-131-\tpipe = hdev-\u003egate2pipe[gate];\nnet/nfc/hci/command.c:132:\tif (pipe == NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-133-\t\treturn -EADDRNOTAVAIL;\n--\nnet/nfc/hci/command.c=140=int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,\n--\nnet/nfc/hci/command.c-162-\nnet/nfc/hci/command.c:163:\tr = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,\nnet/nfc/hci/command.c-164-\t\t\t     tmp, param_len + 1, NULL);\n--\nnet/nfc/hci/command.c=172=int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,\n--\nnet/nfc/hci/command.c-176-\nnet/nfc/hci/command.c:177:\treturn nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,\nnet/nfc/hci/command.c-178-\t\t\t\t\u0026idx, 1, skb);\n--\nnet/nfc/hci/command.c=182=static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)\n--\nnet/nfc/hci/command.c-188-\nnet/nfc/hci/command.c:189:\tr = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,\nnet/nfc/hci/command.c-190-\t\t\t\tNULL, 0, \u0026skb);\n--\nnet/nfc/hci/command.c=202=static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)\nnet/nfc/hci/command.c-203-{\nnet/nfc/hci/command.c:204:\treturn nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,\nnet/nfc/hci/command.c-205-\t\t\t\t   NULL, 0, NULL);\n--\nnet/nfc/hci/command.c=208=static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,\n--\nnet/nfc/hci/command.c-217-\nnet/nfc/hci/command.c:218:\tparams.src_gate = NFC_HCI_ADMIN_GATE;\nnet/nfc/hci/command.c-219-\tparams.dest_host = dest_host;\n--\nnet/nfc/hci/command.c-221-\nnet/nfc/hci/command.c:222:\t*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\nnet/nfc/hci/command.c:223:\t\t\t\t      NFC_HCI_ADM_CREATE_PIPE,\nnet/nfc/hci/command.c-224-\t\t\t\t      (u8 *) \u0026params, sizeof(params), \u0026skb);\nnet/nfc/hci/command.c-225-\tif (*result \u003c 0)\nnet/nfc/hci/command.c:226:\t\treturn NFC_HCI_INVALID_PIPE;\nnet/nfc/hci/command.c-227-\n--\nnet/nfc/hci/command.c-230-\t\t*result = -EPROTO;\nnet/nfc/hci/command.c:231:\t\treturn NFC_HCI_INVALID_PIPE;\nnet/nfc/hci/command.c-232-\t}\n--\nnet/nfc/hci/command.c-236-\nnet/nfc/hci/command.c:237:\tif (pipe \u003e= NFC_HCI_MAX_PIPES) {\nnet/nfc/hci/command.c-238-\t\t*result = -EINVAL;\nnet/nfc/hci/command.c:239:\t\treturn NFC_HCI_INVALID_PIPE;\nnet/nfc/hci/command.c-240-\t}\n--\nnet/nfc/hci/command.c=246=static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)\nnet/nfc/hci/command.c-247-{\nnet/nfc/hci/command.c:248:\treturn nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\nnet/nfc/hci/command.c:249:\t\t\t\t   NFC_HCI_ADM_DELETE_PIPE, \u0026pipe, 1, NULL);\nnet/nfc/hci/command.c-250-}\n--\nnet/nfc/hci/command.c=252=static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)\n--\nnet/nfc/hci/command.c-259-\nnet/nfc/hci/command.c:260:\tif (test_bit(NFC_HCI_QUIRK_SHORT_CLEAR, \u0026hdev-\u003equirks))\nnet/nfc/hci/command.c-261-\t\tparam_len = 0;\nnet/nfc/hci/command.c-262-\nnet/nfc/hci/command.c:263:\treturn nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\nnet/nfc/hci/command.c:264:\t\t\t\t   NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,\nnet/nfc/hci/command.c-265-\t\t\t\t   NULL);\n--\nnet/nfc/hci/command.c=268=int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)\n--\nnet/nfc/hci/command.c-272-\nnet/nfc/hci/command.c:273:\tif (pipe == NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-274-\t\treturn -EADDRNOTAVAIL;\n--\nnet/nfc/hci/command.c-279-\nnet/nfc/hci/command.c:280:\tif (pipe != NFC_HCI_LINK_MGMT_PIPE \u0026\u0026 pipe != NFC_HCI_ADMIN_PIPE) {\nnet/nfc/hci/command.c-281-\t\tr = nfc_hci_delete_pipe(hdev, pipe);\n--\nnet/nfc/hci/command.c-285-\nnet/nfc/hci/command.c:286:\thdev-\u003egate2pipe[gate] = NFC_HCI_INVALID_PIPE;\nnet/nfc/hci/command.c-287-\n--\nnet/nfc/hci/command.c=306=int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,\n--\nnet/nfc/hci/command.c-311-\nnet/nfc/hci/command.c:312:\tif (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)\nnet/nfc/hci/command.c-313-\t\treturn 0;\nnet/nfc/hci/command.c-314-\nnet/nfc/hci/command.c:315:\tif (hdev-\u003egate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-316-\t\treturn -EADDRINUSE;\nnet/nfc/hci/command.c-317-\nnet/nfc/hci/command.c:318:\tif (pipe != NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-319-\t\tgoto open_pipe;\n--\nnet/nfc/hci/command.c-321-\tswitch (dest_gate) {\nnet/nfc/hci/command.c:322:\tcase NFC_HCI_LINK_MGMT_GATE:\nnet/nfc/hci/command.c:323:\t\tpipe = NFC_HCI_LINK_MGMT_PIPE;\nnet/nfc/hci/command.c-324-\t\tbreak;\nnet/nfc/hci/command.c:325:\tcase NFC_HCI_ADMIN_GATE:\nnet/nfc/hci/command.c:326:\t\tpipe = NFC_HCI_ADMIN_PIPE;\nnet/nfc/hci/command.c-327-\t\tbreak;\n--\nnet/nfc/hci/command.c-329-\t\tpipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, \u0026r);\nnet/nfc/hci/command.c:330:\t\tif (pipe == NFC_HCI_INVALID_PIPE)\nnet/nfc/hci/command.c-331-\t\t\treturn r;\n--\nnet/nfc/hci/core.c=22=int nfc_hci_result_to_errno(u8 result)\n--\nnet/nfc/hci/core.c-24-\tswitch (result) {\nnet/nfc/hci/core.c:25:\tcase NFC_HCI_ANY_OK:\nnet/nfc/hci/core.c-26-\t\treturn 0;\nnet/nfc/hci/core.c:27:\tcase NFC_HCI_ANY_E_REG_PAR_UNKNOWN:\nnet/nfc/hci/core.c-28-\t\treturn -EOPNOTSUPP;\nnet/nfc/hci/core.c:29:\tcase NFC_HCI_ANY_E_TIMEOUT:\nnet/nfc/hci/core.c-30-\t\treturn -ETIME;\n--\nnet/nfc/hci/core.c=37=void nfc_hci_reset_pipes(struct nfc_hci_dev *hdev)\n--\nnet/nfc/hci/core.c-40-\nnet/nfc/hci/core.c:41:\tfor (i = 0; i \u003c NFC_HCI_MAX_PIPES; i++) {\nnet/nfc/hci/core.c:42:\t\thdev-\u003epipes[i].gate = NFC_HCI_INVALID_GATE;\nnet/nfc/hci/core.c:43:\t\thdev-\u003epipes[i].dest_host = NFC_HCI_INVALID_HOST;\nnet/nfc/hci/core.c-44-\t}\nnet/nfc/hci/core.c:45:\tmemset(hdev-\u003egate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev-\u003egate2pipe));\nnet/nfc/hci/core.c-46-}\n--\nnet/nfc/hci/core.c=49=void nfc_hci_reset_pipes_per_host(struct nfc_hci_dev *hdev, u8 host)\n--\nnet/nfc/hci/core.c-52-\nnet/nfc/hci/core.c:53:\tfor (i = 0; i \u003c NFC_HCI_MAX_PIPES; i++) {\nnet/nfc/hci/core.c-54-\t\tif (hdev-\u003epipes[i].dest_host != host)\n--\nnet/nfc/hci/core.c-56-\nnet/nfc/hci/core.c:57:\t\thdev-\u003epipes[i].gate = NFC_HCI_INVALID_GATE;\nnet/nfc/hci/core.c:58:\t\thdev-\u003epipes[i].dest_host = NFC_HCI_INVALID_HOST;\nnet/nfc/hci/core.c-59-\t}\n--\nnet/nfc/hci/core.c=126=static void nfc_hci_msg_rx_work(struct work_struct *work)\n--\nnet/nfc/hci/core.c-137-\t\tpipe = skb-\u003edata[0];\nnet/nfc/hci/core.c:138:\t\tskb_pull(skb, NFC_HCI_HCP_PACKET_HEADER_LEN);\nnet/nfc/hci/core.c-139-\t\tmessage = (struct hcp_message *)skb-\u003edata;\n--\nnet/nfc/hci/core.c-141-\t\tinstruction = HCP_MSG_GET_CMD(message-\u003eheader);\nnet/nfc/hci/core.c:142:\t\tskb_pull(skb, NFC_HCI_HCP_MESSAGE_HEADER_LEN);\nnet/nfc/hci/core.c-143-\n--\nnet/nfc/hci/core.c=181=void nfc_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,\n--\nnet/nfc/hci/core.c-183-{\nnet/nfc/hci/core.c:184:\tu8 status = NFC_HCI_ANY_OK;\nnet/nfc/hci/core.c-185-\tconst struct hci_create_pipe_resp *create_info;\n--\nnet/nfc/hci/core.c-191-\nnet/nfc/hci/core.c:192:\tif (pipe \u003e= NFC_HCI_MAX_PIPES) {\nnet/nfc/hci/core.c:193:\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-194-\t\tgoto exit;\n--\nnet/nfc/hci/core.c-199-\tswitch (cmd) {\nnet/nfc/hci/core.c:200:\tcase NFC_HCI_ADM_NOTIFY_PIPE_CREATED:\nnet/nfc/hci/core.c-201-\t\tif (skb-\u003elen != 5) {\nnet/nfc/hci/core.c:202:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-203-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-206-\nnet/nfc/hci/core.c:207:\t\tif (create_info-\u003epipe \u003e= NFC_HCI_MAX_PIPES) {\nnet/nfc/hci/core.c:208:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-209-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-221-\t\tbreak;\nnet/nfc/hci/core.c:222:\tcase NFC_HCI_ANY_OPEN_PIPE:\nnet/nfc/hci/core.c:223:\t\tif (gate == NFC_HCI_INVALID_GATE) {\nnet/nfc/hci/core.c:224:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-225-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-227-\t\tbreak;\nnet/nfc/hci/core.c:228:\tcase NFC_HCI_ADM_NOTIFY_PIPE_DELETED:\nnet/nfc/hci/core.c-229-\t\tif (skb-\u003elen != 1) {\nnet/nfc/hci/core.c:230:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-231-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-234-\nnet/nfc/hci/core.c:235:\t\tif (delete_info-\u003epipe \u003e= NFC_HCI_MAX_PIPES) {\nnet/nfc/hci/core.c:236:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-237-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-239-\nnet/nfc/hci/core.c:240:\t\thdev-\u003epipes[delete_info-\u003epipe].gate = NFC_HCI_INVALID_GATE;\nnet/nfc/hci/core.c:241:\t\thdev-\u003epipes[delete_info-\u003epipe].dest_host = NFC_HCI_INVALID_HOST;\nnet/nfc/hci/core.c-242-\t\tbreak;\nnet/nfc/hci/core.c:243:\tcase NFC_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED:\nnet/nfc/hci/core.c-244-\t\tif (skb-\u003elen != 1) {\nnet/nfc/hci/core.c:245:\t\t\tstatus = NFC_HCI_ANY_E_NOK;\nnet/nfc/hci/core.c-246-\t\t\tgoto exit;\n--\nnet/nfc/hci/core.c-260-exit:\nnet/nfc/hci/core.c:261:\tnfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_RESPONSE,\nnet/nfc/hci/core.c-262-\t\t\t       status, NULL, 0, NULL, NULL, 0);\n--\nnet/nfc/hci/core.c=267=u32 nfc_hci_sak_to_protocol(u8 sak)\nnet/nfc/hci/core.c-268-{\nnet/nfc/hci/core.c:269:\tswitch (NFC_HCI_TYPE_A_SEL_PROT(sak)) {\nnet/nfc/hci/core.c:270:\tcase NFC_HCI_TYPE_A_SEL_PROT_MIFARE:\nnet/nfc/hci/core.c-271-\t\treturn NFC_PROTO_MIFARE_MASK;\nnet/nfc/hci/core.c:272:\tcase NFC_HCI_TYPE_A_SEL_PROT_ISO14443:\nnet/nfc/hci/core.c-273-\t\treturn NFC_PROTO_ISO14443_MASK;\nnet/nfc/hci/core.c:274:\tcase NFC_HCI_TYPE_A_SEL_PROT_DEP:\nnet/nfc/hci/core.c-275-\t\treturn NFC_PROTO_NFC_DEP_MASK;\nnet/nfc/hci/core.c:276:\tcase NFC_HCI_TYPE_A_SEL_PROT_ISO14443_DEP:\nnet/nfc/hci/core.c-277-\t\treturn NFC_PROTO_ISO14443_MASK | NFC_PROTO_NFC_DEP_MASK;\n--\nnet/nfc/hci/core.c=284=int nfc_hci_target_discovered(struct nfc_hci_dev *hdev, u8 gate)\n--\nnet/nfc/hci/core.c-298-\tswitch (gate) {\nnet/nfc/hci/core.c:299:\tcase NFC_HCI_RF_READER_A_GATE:\nnet/nfc/hci/core.c:300:\t\tr = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:301:\t\t\t\t      NFC_HCI_RF_READER_A_ATQA, \u0026atqa_skb);\nnet/nfc/hci/core.c-302-\t\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c-304-\nnet/nfc/hci/core.c:305:\t\tr = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:306:\t\t\t\t      NFC_HCI_RF_READER_A_SAK, \u0026sak_skb);\nnet/nfc/hci/core.c-307-\t\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c-324-\nnet/nfc/hci/core.c:325:\t\tr = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:326:\t\t\t\t      NFC_HCI_RF_READER_A_UID, \u0026uid_skb);\nnet/nfc/hci/core.c-327-\t\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c-344-\t\tbreak;\nnet/nfc/hci/core.c:345:\tcase NFC_HCI_RF_READER_B_GATE:\nnet/nfc/hci/core.c-346-\t\ttargets-\u003esupported_protocols = NFC_PROTO_ISO14443_B_MASK;\n--\nnet/nfc/hci/core.c=381=void nfc_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe, u8 event,\n--\nnet/nfc/hci/core.c-386-\nnet/nfc/hci/core.c:387:\tif (pipe \u003e= NFC_HCI_MAX_PIPES) {\nnet/nfc/hci/core.c-388-\t\tpr_err(\"Discarded event %x to invalid pipe %x\\n\", event, pipe);\n--\nnet/nfc/hci/core.c-392-\tgate = hdev-\u003epipes[pipe].gate;\nnet/nfc/hci/core.c:393:\tif (gate == NFC_HCI_INVALID_GATE) {\nnet/nfc/hci/core.c-394-\t\tpr_err(\"Discarded event %x to unopened pipe %x\\n\", event, pipe);\n--\nnet/nfc/hci/core.c-404-\tswitch (event) {\nnet/nfc/hci/core.c:405:\tcase NFC_HCI_EVT_TARGET_DISCOVERED:\nnet/nfc/hci/core.c-406-\t\tif (skb-\u003elen \u003c 1) {\t/* no status data? */\n--\nnet/nfc/hci/core.c=449=static int hci_dev_connect_gates(struct nfc_hci_dev *hdev, u8 gate_count,\n--\nnet/nfc/hci/core.c-453-\twhile (gate_count--) {\nnet/nfc/hci/core.c:454:\t\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\nnet/nfc/hci/core.c-455-\t\t\t\t\t gates-\u003egate, gates-\u003epipe);\n--\nnet/nfc/hci/core.c=464=static int hci_dev_session_init(struct nfc_hci_dev *hdev)\n--\nnet/nfc/hci/core.c-468-\nnet/nfc/hci/core.c:469:\tif (hdev-\u003einit_data.gates[0].gate != NFC_HCI_ADMIN_GATE)\nnet/nfc/hci/core.c-470-\t\treturn -EPROTO;\nnet/nfc/hci/core.c-471-\nnet/nfc/hci/core.c:472:\tr = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,\nnet/nfc/hci/core.c-473-\t\t\t\t hdev-\u003einit_data.gates[0].gate,\n--\nnet/nfc/hci/core.c-477-\nnet/nfc/hci/core.c:478:\tr = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,\nnet/nfc/hci/core.c:479:\t\t\t      NFC_HCI_ADMIN_SESSION_IDENTITY, \u0026skb);\nnet/nfc/hci/core.c-480-\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c-502-\nnet/nfc/hci/core.c:503:\t\tr = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,\nnet/nfc/hci/core.c:504:\t\t\t\tNFC_HCI_ADMIN_SESSION_IDENTITY,\nnet/nfc/hci/core.c-505-\t\t\t\thdev-\u003einit_data.session_id,\n--\nnet/nfc/hci/core.c=520=static int hci_dev_version(struct nfc_hci_dev *hdev)\n--\nnet/nfc/hci/core.c-524-\nnet/nfc/hci/core.c:525:\tr = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,\nnet/nfc/hci/core.c:526:\t\t\t      NFC_HCI_ID_MGMT_VERSION_SW, \u0026skb);\nnet/nfc/hci/core.c-527-\tif (r == -EOPNOTSUPP) {\n--\nnet/nfc/hci/core.c-545-\nnet/nfc/hci/core.c:546:\tr = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,\nnet/nfc/hci/core.c:547:\t\t\t      NFC_HCI_ID_MGMT_VERSION_HW, \u0026skb);\nnet/nfc/hci/core.c-548-\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c=579=static int hci_dev_up(struct nfc_dev *nfc_dev)\n--\nnet/nfc/hci/core.c-597-\nnet/nfc/hci/core.c:598:\tr = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:599:\t\t\t       NFC_HCI_EVT_END_OPERATION, NULL, 0);\nnet/nfc/hci/core.c-600-\tif (r \u003c 0)\n--\nnet/nfc/hci/core.c=639=static int hci_start_poll(struct nfc_dev *nfc_dev,\n--\nnet/nfc/hci/core.c-646-\telse\nnet/nfc/hci/core.c:647:\t\treturn nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:648:\t\t\t\t\t  NFC_HCI_EVT_READER_REQUESTED,\nnet/nfc/hci/core.c-649-\t\t\t\t\t  NULL, 0);\n--\nnet/nfc/hci/core.c=652=static void hci_stop_poll(struct nfc_dev *nfc_dev)\n--\nnet/nfc/hci/core.c-658-\telse\nnet/nfc/hci/core.c:659:\t\tnfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,\nnet/nfc/hci/core.c:660:\t\t\t\t   NFC_HCI_EVT_END_OPERATION, NULL, 0);\nnet/nfc/hci/core.c-661-}\n--\nnet/nfc/hci/core.c=722=static int hci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,\n--\nnet/nfc/hci/core.c-731-\tswitch (target-\u003ehci_reader_gate) {\nnet/nfc/hci/core.c:732:\tcase NFC_HCI_RF_READER_A_GATE:\nnet/nfc/hci/core.c:733:\tcase NFC_HCI_RF_READER_B_GATE:\nnet/nfc/hci/core.c-734-\t\tif (hdev-\u003eops-\u003eim_transceive) {\n--\nnet/nfc/hci/core.c-747-\t\tr = nfc_hci_send_cmd_async(hdev, target-\u003ehci_reader_gate,\nnet/nfc/hci/core.c:748:\t\t\t\t\t   NFC_HCI_WR_XCHG_DATA, skb-\u003edata,\nnet/nfc/hci/core.c-749-\t\t\t\t\t   skb-\u003elen, hci_transceive_cb, hdev);\n--\nnet/nfc/hci/core.c=854=static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb)\n--\nnet/nfc/hci/core.c-863-\nnet/nfc/hci/core.c:864:\tif (!pskb_may_pull(skb, NFC_HCI_HCP_PACKET_HEADER_LEN)) {\nnet/nfc/hci/core.c-865-\t\tkfree_skb(skb);\n--\nnet/nfc/hci/core.c-869-\tpacket = (struct hcp_packet *)skb-\u003edata;\nnet/nfc/hci/core.c:870:\tif ((packet-\u003eheader \u0026 ~NFC_HCI_FRAGMENT) == 0) {\nnet/nfc/hci/core.c-871-\t\tskb_queue_tail(\u0026hdev-\u003erx_hcp_frags, skb);\n--\nnet/nfc/hci/core.c-876-\tif (skb_queue_len(\u0026hdev-\u003erx_hcp_frags)) {\nnet/nfc/hci/core.c:877:\t\tpipe = packet-\u003eheader \u0026 NFC_HCI_FRAGMENT;\nnet/nfc/hci/core.c-878-\t\tskb_queue_tail(\u0026hdev-\u003erx_hcp_frags, skb);\n--\nnet/nfc/hci/core.c-882-\t\t\tmsg_len += (frag_skb-\u003elen -\nnet/nfc/hci/core.c:883:\t\t\t\t    NFC_HCI_HCP_PACKET_HEADER_LEN);\nnet/nfc/hci/core.c-884-\t\t}\nnet/nfc/hci/core.c-885-\nnet/nfc/hci/core.c:886:\t\thcp_skb = nfc_alloc_recv_skb(NFC_HCI_HCP_PACKET_HEADER_LEN +\nnet/nfc/hci/core.c-887-\t\t\t\t\t     msg_len, GFP_KERNEL);\n--\nnet/nfc/hci/core.c-895-\t\tskb_queue_walk(\u0026hdev-\u003erx_hcp_frags, frag_skb) {\nnet/nfc/hci/core.c:896:\t\t\tmsg_len = frag_skb-\u003elen - NFC_HCI_HCP_PACKET_HEADER_LEN;\nnet/nfc/hci/core.c-897-\t\t\tskb_put_data(hcp_skb,\nnet/nfc/hci/core.c:898:\t\t\t\t     frag_skb-\u003edata + NFC_HCI_HCP_PACKET_HEADER_LEN,\nnet/nfc/hci/core.c-899-\t\t\t\t     msg_len);\n--\nnet/nfc/hci/core.c-903-\t} else {\nnet/nfc/hci/core.c:904:\t\tpacket-\u003eheader \u0026= NFC_HCI_FRAGMENT;\nnet/nfc/hci/core.c-905-\t\thcp_skb = skb;\n--\nnet/nfc/hci/core.c-911-\t */\nnet/nfc/hci/core.c:912:\tif (!pskb_may_pull(hcp_skb, NFC_HCI_HCP_HEADER_LEN)) {\nnet/nfc/hci/core.c-913-\t\tkfree_skb(hcp_skb);\n--\nnet/nfc/hci/core.c-918-\ttype = HCP_MSG_GET_TYPE(packet-\u003emessage.header);\nnet/nfc/hci/core.c:919:\tif (type == NFC_HCI_HCP_RESPONSE) {\nnet/nfc/hci/core.c-920-\t\tpipe = packet-\u003eheader;\nnet/nfc/hci/core.c-921-\t\tinstruction = HCP_MSG_GET_CMD(packet-\u003emessage.header);\nnet/nfc/hci/core.c:922:\t\tskb_pull(hcp_skb, NFC_HCI_HCP_PACKET_HEADER_LEN +\nnet/nfc/hci/core.c:923:\t\t\t NFC_HCI_HCP_MESSAGE_HEADER_LEN);\nnet/nfc/hci/core.c-924-\t\tnfc_hci_hcp_message_rx(hdev, pipe, type, instruction, hcp_skb);\n--\nnet/nfc/hci/hci.h=60=struct hci_all_pipe_cleared_noti {\n--\nnet/nfc/hci/hci.h-63-\nnet/nfc/hci/hci.h:64:#define NFC_HCI_FRAGMENT\t0x7f\nnet/nfc/hci/hci.h-65-\n--\nnet/nfc/hci/hci.h=76=void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,\n--\nnet/nfc/hci/hci.h-79-/* HCP headers */\nnet/nfc/hci/hci.h:80:#define NFC_HCI_HCP_PACKET_HEADER_LEN\t1\nnet/nfc/hci/hci.h:81:#define NFC_HCI_HCP_MESSAGE_HEADER_LEN\t1\nnet/nfc/hci/hci.h:82:#define NFC_HCI_HCP_HEADER_LEN\t\t2\nnet/nfc/hci/hci.h-83-\nnet/nfc/hci/hci.h-84-/* HCP types */\nnet/nfc/hci/hci.h:85:#define NFC_HCI_HCP_COMMAND\t0x00\nnet/nfc/hci/hci.h:86:#define NFC_HCI_HCP_EVENT\t0x01\nnet/nfc/hci/hci.h:87:#define NFC_HCI_HCP_RESPONSE\t0x02\nnet/nfc/hci/hci.h-88-\nnet/nfc/hci/hci.h-89-/* Generic commands */\nnet/nfc/hci/hci.h:90:#define NFC_HCI_ANY_SET_PARAMETER\t0x01\nnet/nfc/hci/hci.h:91:#define NFC_HCI_ANY_GET_PARAMETER\t0x02\nnet/nfc/hci/hci.h:92:#define NFC_HCI_ANY_OPEN_PIPE\t\t0x03\nnet/nfc/hci/hci.h:93:#define NFC_HCI_ANY_CLOSE_PIPE\t\t0x04\nnet/nfc/hci/hci.h-94-\nnet/nfc/hci/hci.h-95-/* Reader RF commands */\nnet/nfc/hci/hci.h:96:#define NFC_HCI_WR_XCHG_DATA\t\t0x10\nnet/nfc/hci/hci.h-97-\nnet/nfc/hci/hci.h-98-/* Admin commands */\nnet/nfc/hci/hci.h:99:#define NFC_HCI_ADM_CREATE_PIPE\t\t\t0x10\nnet/nfc/hci/hci.h:100:#define NFC_HCI_ADM_DELETE_PIPE\t\t\t0x11\nnet/nfc/hci/hci.h:101:#define NFC_HCI_ADM_NOTIFY_PIPE_CREATED\t\t0x12\nnet/nfc/hci/hci.h:102:#define NFC_HCI_ADM_NOTIFY_PIPE_DELETED\t\t0x13\nnet/nfc/hci/hci.h:103:#define NFC_HCI_ADM_CLEAR_ALL_PIPE\t\t0x14\nnet/nfc/hci/hci.h:104:#define NFC_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED\t0x15\nnet/nfc/hci/hci.h-105-\nnet/nfc/hci/hci.h-106-/* Generic responses */\nnet/nfc/hci/hci.h:107:#define NFC_HCI_ANY_OK\t\t\t\t0x00\nnet/nfc/hci/hci.h:108:#define NFC_HCI_ANY_E_NOT_CONNECTED\t\t0x01\nnet/nfc/hci/hci.h:109:#define NFC_HCI_ANY_E_CMD_PAR_UNKNOWN\t\t0x02\nnet/nfc/hci/hci.h:110:#define NFC_HCI_ANY_E_NOK\t\t\t0x03\nnet/nfc/hci/hci.h:111:#define NFC_HCI_ANY_E_PIPES_FULL\t\t0x04\nnet/nfc/hci/hci.h:112:#define NFC_HCI_ANY_E_REG_PAR_UNKNOWN\t\t0x05\nnet/nfc/hci/hci.h:113:#define NFC_HCI_ANY_E_PIPE_NOT_OPENED\t\t0x06\nnet/nfc/hci/hci.h:114:#define NFC_HCI_ANY_E_CMD_NOT_SUPPORTED\t\t0x07\nnet/nfc/hci/hci.h:115:#define NFC_HCI_ANY_E_INHIBITED\t\t\t0x08\nnet/nfc/hci/hci.h:116:#define NFC_HCI_ANY_E_TIMEOUT\t\t\t0x09\nnet/nfc/hci/hci.h:117:#define NFC_HCI_ANY_E_REG_ACCESS_DENIED\t\t0x0a\nnet/nfc/hci/hci.h:118:#define NFC_HCI_ANY_E_PIPE_ACCESS_DENIED\t0x0b\nnet/nfc/hci/hci.h-119-\n--\nnet/nfc/hci/hcp.c=21=int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,\n--\nnet/nfc/hci/hcp.c-38-\tskb_queue_head_init(\u0026cmd-\u003emsg_frags);\nnet/nfc/hci/hcp.c:39:\tcmd-\u003ewait_response = (type == NFC_HCI_HCP_COMMAND) ? true : false;\nnet/nfc/hci/hcp.c-40-\tcmd-\u003ecb = cb;\n--\nnet/nfc/hci/hcp.c-49-\nnet/nfc/hci/hcp.c:50:\t\tif (NFC_HCI_HCP_PACKET_HEADER_LEN + hci_len \u003c=\nnet/nfc/hci/hcp.c-51-\t\t    hdev-\u003emax_data_link_payload)\n--\nnet/nfc/hci/hcp.c-54-\t\t\tdata_link_len = hdev-\u003emax_data_link_payload -\nnet/nfc/hci/hcp.c:55:\t\t\t\t\tNFC_HCI_HCP_PACKET_HEADER_LEN;\nnet/nfc/hci/hcp.c-56-\nnet/nfc/hci/hcp.c:57:\t\tskb_len = ndev-\u003etx_headroom + NFC_HCI_HCP_PACKET_HEADER_LEN +\nnet/nfc/hci/hcp.c-58-\t\t\t  data_link_len + ndev-\u003etx_tailroom;\n--\nnet/nfc/hci/hcp.c-67-\nnet/nfc/hci/hcp.c:68:\t\tskb_put(skb, NFC_HCI_HCP_PACKET_HEADER_LEN + data_link_len);\nnet/nfc/hci/hcp.c-69-\n--\nnet/nfc/hci/hcp.c-85-\t\tif (hci_len == 0)\nnet/nfc/hci/hcp.c:86:\t\t\tpacket-\u003eheader |= ~NFC_HCI_FRAGMENT;\nnet/nfc/hci/hcp.c-87-\n--\nnet/nfc/hci/hcp.c=117=void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,\n--\nnet/nfc/hci/hcp.c-120-\tswitch (type) {\nnet/nfc/hci/hcp.c:121:\tcase NFC_HCI_HCP_RESPONSE:\nnet/nfc/hci/hcp.c-122-\t\tnfc_hci_resp_received(hdev, instruction, skb);\nnet/nfc/hci/hcp.c-123-\t\tbreak;\nnet/nfc/hci/hcp.c:124:\tcase NFC_HCI_HCP_COMMAND:\nnet/nfc/hci/hcp.c-125-\t\tnfc_hci_cmd_received(hdev, pipe, instruction, skb);\nnet/nfc/hci/hcp.c-126-\t\tbreak;\nnet/nfc/hci/hcp.c:127:\tcase NFC_HCI_HCP_EVENT:\nnet/nfc/hci/hcp.c-128-\t\tnfc_hci_event_received(hdev, pipe, instruction, skb);\n"
}

gemini-3.8-flash

null

null

							input: 44876
							output: 35
							thoughts: 281
						

**Analyzing NFC HCI Symbol Dependencies**

Okay, let's break this down. I'm looking at `nfc_hci_create_pipe`, a static function tucked away in `net/nfc/hci/command.c`. The fact that it's static immediately flags that the compiler *could* inline it, especially given that `nfc_hci_connect_gate` is its sole caller. So, even though it's static, I need to include *both* `nfc_hci_create_pipe` and the exported `nfc_hci_connect_gate` in `FocusSymbols` to be safe. It’s the smart play to ensure complete coverage of the call path.

Now, what else is crucial in this flow? I need to think bigger and map out the relevant execution path. Let's see... besides these two, I'm thinking I also need to consider `nfc_hci_execute_cmd`, `nfc_hci_resp_received`, `hci_dev_connect_gates`, and `hci_dev_session_init`. These are likely all part of the crucial sequence of events.

And, of course, the kernel configuration. I need to make sure the relevant Kconfig options are set.  The essentials are `NFC` and `NFC_HCI`. `NFC_SHDLC` is often enabled in conjunction with `NFC_HCI`, so it's probably relevant too, although optional. I should probably dig into the `net/nfc/hci/Kconfig` file to see if there are any other specific configurations required or relevant to the HCI implementation.

{
  "File": "net/nfc/hci/Kconfig",
  "FirstLine": 1,
  "LineCount": 20
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0-only\n   2:\tconfig NFC_HCI\n   3:\t\tdepends on NFC\n   4:\t\ttristate \"NFC HCI implementation\"\n   5:\t\tdefault n\n   6:\t\thelp\n   7:\t\t  Say Y here if you want to build support for a kernel NFC HCI\n   8:\t\t  implementation. This is mostly needed for devices that only process\n   9:\t\t  HCI frames, like for example the NXP pn544.\n  10:\t\n  11:\tconfig NFC_SHDLC\n  12:\t\tdepends on NFC_HCI\n  13:\t\tselect CRC_CCITT\n  14:\t\tbool \"SHDLC link layer for HCI based NFC drivers\"\n  15:\t\tdefault n\n  16:\t\thelp\n  17:\t\t  Say yes if you use an NFC HCI driver that requires SHDLC link layer.\n  18:\t\t  If unsure, say N here.\n"
}

gemini-3.8-flash

null

null

							input: 45785
							output: 33
							thoughts: 13
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Diving into the NFC Configuration**

Alright, let's get down to brass tacks. I need to understand the NFC configuration options within the kernel. The logical first step is to dig into the `net/nfc/Kconfig` file. I'm hoping it's well-structured and documented, allowing me to quickly grasp the available features, dependencies, and default settings related to NFC functionality. I expect to find definitions for enabling/disabling different NFC controllers, protocol support, and any related power management features. My immediate goal is to get a high-level overview of the configuration landscape before diving deeper into specific drivers or subsystems. From here I plan to understand how best to tailor the configuration to the specific needs of the project.

{
  "File": "net/nfc/Kconfig",
  "FirstLine": 1,
  "LineCount": 40
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0-only\n   2:\t#\n   3:\t# NFC subsystem configuration\n   4:\t#\n   5:\t\n   6:\tmenuconfig NFC\n   7:\t\tdepends on RFKILL || !RFKILL\n   8:\t\ttristate \"NFC subsystem support\"\n   9:\t\tdefault n\n  10:\t\thelp\n  11:\t\t  Say Y here if you want to build support for NFC (Near field\n  12:\t\t  communication) devices.\n  13:\t\n  14:\t\t  To compile this support as a module, choose M here: the module will\n  15:\t\t  be called nfc.\n  16:\t\n  17:\tconfig NFC_DIGITAL\n  18:\t\tdepends on NFC\n  19:\t\tselect CRC_CCITT\n  20:\t\tselect CRC_ITU_T\n  21:\t\ttristate \"NFC Digital Protocol stack support\"\n  22:\t\tdefault n\n  23:\t\thelp\n  24:\t\t  Say Y if you want to build NFC digital protocol stack support.\n  25:\t\t  This is needed by NFC chipsets whose firmware only implement\n  26:\t\t  the NFC analog layer.\n  27:\t\n  28:\t\t  To compile this support as a module, choose M here: the module will\n  29:\t\t  be called nfc_digital.\n  30:\t\n  31:\tsource \"net/nfc/nci/Kconfig\"\n  32:\tsource \"net/nfc/hci/Kconfig\"\n  33:\t\n  34:\tsource \"drivers/nfc/Kconfig\"\n"
}

gemini-3.8-flash

null

null

							input: 46420
							output: 155
							thoughts: 359
						

**Fuzzing Target Assessment: NFC HCI Bounds Validation**

Okay, this looks pretty clear-cut. Let's run through the WorthFuzzing checklist, just to be absolutely certain. The patch modifies `net/nfc/hci/command.c`, which immediately flags my interest as networking/protocol code is prime fuzzing territory. Specifically, the fix addresses bounds validation within `nfc_hci_create_pipe`. This prevents out-of-bounds memory access during HCI frame handling, specifically the write to `hdev->pipes[pipe]` and the read from `skb->data`.

This is a clear win – we can craft malformed responses and explore various edge cases to ensure robust error handling and, crucially, no regressions or memory corruption. This confirms it: **WorthFuzzing = true.**

Now, let's nail down the critical functions. The primary focus is `nfc_hci_create_pipe`, the function that was directly modified. We should also include the caller, `nfc_hci_connect_gate`, which resides in the same file. Additionally, `hci_dev_connect_gates` and `hci_dev_session_init` from `net/nfc/hci/core.c` seem relevant for broader testing.

I'm doing a quick sanity check of `FocusSymbols` and `EnableConfigs` to make sure they're consistent. Alright, seems good, we have a clear path to follow.

The necessary configurations are `NFC`, `NFC_HCI`, and `NFC_SHDLC`. Note: no `CONFIG_` prefix.

My rationale is straightforward: This patch introduces a crucial bounds check within the NFC HCI protocol stack to prevent memory corruption. It is reachable through normal operation. By fuzzing the affected functions and the broader HCI interface, we can confirm the robustness of this fix and identify any potential regressions. The specified focus symbols and configurations will guide the fuzzing process.

Time to call `set-results`.

{
  "EnableConfigs": [
    "NFC",
    "NFC_HCI",
    "NFC_SHDLC"
  ],
  "FocusSymbols": [
    "nfc_hci_create_pipe",
    "nfc_hci_connect_gate",
    "hci_dev_connect_gates",
    "hci_dev_session_init"
  ],
  "Reasoning": "The patch adds length and bounds checks in nfc_hci_create_pipe() to prevent out-of-bounds reads and writes when processing response frames from an NFC controller. This executable networking code is reachable during NFC HCI device initialization and session management, warranting fuzzing to ensure robustness against malformed responses.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "NFC",
    "NFC_HCI",
    "NFC_SHDLC"
  ],
  "FocusSymbols": [
    "nfc_hci_create_pipe",
    "nfc_hci_connect_gate",
    "hci_dev_connect_gates",
    "hci_dev_session_init"
  ],
  "Reasoning": "The patch adds length and bounds checks in nfc_hci_create_pipe() to prevent out-of-bounds reads and writes when processing response frames from an NFC controller. This executable networking code is reachable during NFC HCI device initialization and session management, warranting fuzzing to ensure robustness against malformed responses.",
  "WorthFuzzing": true
}

{
  "WorthFuzzing": true
}

null

core

null

{
  "KMSANReasoning": "The patch adds validation checks in `nfc_hci_create_pipe()`:\n1. It verifies that `skb-\u003elen \u003e= sizeof(*resp)` before dereferencing `resp-\u003epipe`, preventing an out-of-bounds read on a truncated skb buffer.\n2. It verifies that `pipe \u003c NFC_HCI_MAX_PIPES`, preventing an out-of-bounds array indexing bug when `hdev-\u003epipes[pipe]` is subsequently accessed in `nfc_hci_connect_gate()`.\n\nThese issues are classical out-of-bounds read/write memory safety vulnerabilities that are detected by KASAN. The patch does not introduce or modify any uninitialized variables, stack/heap allocations, padding bytes, or user-space copies (info-leaks). Therefore, a dedicated KMSAN fuzzing session is not warranted.",
  "NeedsKMSAN": false
}

You are an expert Linux kernel security engineer specializing in kernel memory
error detectors (KASAN and KMSAN). Your job is to review the provided patch series and
determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer)
fuzzing session in addition to standard KASAN fuzzing.

CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN:
- Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable
  a comprehensive suite of debugging tools and sanitizers, including KASAN
  (out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP
  (locking bugs and deadlocks), UB-sanitizers, and memory corruption checks.
- KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap,
  or page allocations) and kernel-to-user memory info-leaks.

Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN,
LOCKDEP, OR OTHER STANDARD BUG DETECTORS.
A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY
set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks
that are detected ONLY by KMSAN.

Look holistically at the patch series and surrounding code. Even if no direct
uninitialized field accesses or new buffer allocations are added in the diff itself,
a patch may alter control flow, bounds checking, or data length calculations in ways
that change how the rest of the code operates on existing buffers (e.g. allowing
uninitialized stack/heap memory to be read, copied to user space, or used in control
flow). Do not hesitate to use your code access tools to inspect the surrounding code,
called functions, and callers.

Set NeedsKMSAN=true ONLY IF the patch introduces or modifies:
1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb
   attributes, ioctl output arguments, socket options, or BPF buffers) where fields
   or structure padding might not be fully initialized/zeroed.
2. Conditional logic or branching that depends on potentially uninitialized variables
   or struct fields.
3. Allocation or initialization of complex data structures where uninitialized fields
   could be read later in reachable code paths.
4. Bounds checks, lengths, or logic in a way that allows surrounding code to access
   uninitialized bytes of existing buffers.

Set NeedsKMSAN=false IF:
- The code changes primarily risk out-of-bounds access, array overflows, NULL pointer
  dereferences, locking deadlocks, or use-after-free bugs (these are already caught
  by KASAN, LOCKDEP, or standard bug detectors).
- All stack/heap structures touched or introduced by the patch are fully zeroed
  or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied.
- The patch does not introduce any risk of uninitialized memory usage or info-leaks.

Use your code access tools to inspect the surrounding code if necessary, then provide
detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch.
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

Target architecture: amd64

For your convenience, here is the diff of the changes:
commit 923dbc502cd0d0256b3b662a960a0ed0c59bdd91
Author: syz-cluster <triage@syzkaller.com>
Date:   Sat Sep 12 12:09:05 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/nfc/hci/command.c b/net/nfc/hci/command.c
index af6bacb3ba986..9c8bcb98b9677 100644
--- a/net/nfc/hci/command.c
+++ b/net/nfc/hci/command.c
@@ -225,10 +225,19 @@ static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
 	if (*result < 0)
 		return NFC_HCI_INVALID_PIPE;
 
+	if (skb->len < sizeof(*resp)) {
+		kfree_skb(skb);
+		*result = -EPROTO;
+		return NFC_HCI_INVALID_PIPE;
+	}
 	resp = (struct hci_create_pipe_resp *)skb->data;
 	pipe = resp->pipe;
 	kfree_skb(skb);
 
+	if (pipe >= NFC_HCI_MAX_PIPES) {
+		*result = -EINVAL;
+		return NFC_HCI_INVALID_PIPE;
+	}
 	pr_debug("pipe created=%d\n", pipe);
 
 	return pipe;

gemini-3.8-flash

null

null

							input: 2195
							output: 38
							thoughts: 61
						

Okay, let's get down to brass tacks.

**Analyzing this Patch: A Deep Dive**

Alright, the first thing I'm doing is zeroing in on this patch and its instructions. It looks like we're dealing with a change within the `net/nfc/hci/` subsystem, specifically touching the `command.c` file. The target is the `nfc_hci_create_pipe` function. This rings a bell; pipe creation in NFC is a crucial area, easily leading to subtle errors.

Now, I need the context. Let's pull up the `net/nfc/hci/command.c` file and jump to around line 225. I need to understand exactly what's being modified within that function. I'll read around that line, carefully taking into account the surrounding code to grasp the complete picture of the change and its implications for how pipes are established. No point diving into the modification without having the original code fresh in my mind!

{
  "File": "net/nfc/hci/command.c",
  "FirstLine": 210,
  "LineCount": 50
}

{
  "Contents": " 210:\t{\n 211:\t\tstruct sk_buff *skb;\n 212:\t\tstruct hci_create_pipe_params params;\n 213:\t\tstruct hci_create_pipe_resp *resp;\n 214:\t\tu8 pipe;\n 215:\t\n 216:\t\tpr_debug(\"gate=%d\\n\", dest_gate);\n 217:\t\n 218:\t\tparams.src_gate = NFC_HCI_ADMIN_GATE;\n 219:\t\tparams.dest_host = dest_host;\n 220:\t\tparams.dest_gate = dest_gate;\n 221:\t\n 222:\t\t*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\n 223:\t\t\t\t\t      NFC_HCI_ADM_CREATE_PIPE,\n 224:\t\t\t\t\t      (u8 *) \u0026params, sizeof(params), \u0026skb);\n 225:\t\tif (*result \u003c 0)\n 226:\t\t\treturn NFC_HCI_INVALID_PIPE;\n 227:\t\n 228:\t\tif (skb-\u003elen \u003c sizeof(*resp)) {\n 229:\t\t\tkfree_skb(skb);\n 230:\t\t\t*result = -EPROTO;\n 231:\t\t\treturn NFC_HCI_INVALID_PIPE;\n 232:\t\t}\n 233:\t\tresp = (struct hci_create_pipe_resp *)skb-\u003edata;\n 234:\t\tpipe = resp-\u003epipe;\n 235:\t\tkfree_skb(skb);\n 236:\t\n 237:\t\tif (pipe \u003e= NFC_HCI_MAX_PIPES) {\n 238:\t\t\t*result = -EINVAL;\n 239:\t\t\treturn NFC_HCI_INVALID_PIPE;\n 240:\t\t}\n 241:\t\tpr_debug(\"pipe created=%d\\n\", pipe);\n 242:\t\n 243:\t\treturn pipe;\n 244:\t}\n 245:\t\n 246:\tstatic int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)\n 247:\t{\n 248:\t\treturn nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,\n 249:\t\t\t\t\t   NFC_HCI_ADM_DELETE_PIPE, \u0026pipe, 1, NULL);\n 250:\t}\n 251:\t\n 252:\tstatic int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)\n 253:\t{\n 254:\t\tu8 param[2];\n 255:\t\tsize_t param_len = 2;\n 256:\t\n 257:\t\t/* TODO: Find out what the identity reference data is\n 258:\t\t * and fill param with it. HCI spec 6.1.3.5 */\n 259:\t\n"
}

gemini-3.8-flash

null

null

							input: 3284
							output: 32
							thoughts: 20
						

Here's my analysis of the `nfc_hci_create_pipe` function and its callers:

**Analyzing `nfc_hci_create_pipe` and Its Usage**

Okay, let's dive into this `nfc_hci_create_pipe` function. My initial goal is to understand its role within the larger NFC HCI architecture. I need to figure out what it's responsible for, the resources it's allocating or managing, and, crucially, who is calling it. Understanding the call stack will be key to grasping its purpose. Is it a central function, or a helper for a specific module? Are there specific types of pipes? What parameters are passed? Let me quickly review the structure definition for the "pipe" it seems to create. Are there any resource constraints associated with this function? Does it deal with memory allocation, and if so, how is that handled? I need to look for potential error conditions and how they are handled (or *not* handled). The error paths are just as important as the success path. So, let me start by tracing the function's usage, and then I'll look deeper at the implementation and any related data structures. I need to be able to fully understand this function's scope, its impact on the system, and potential vulnerabilities before I can offer a meaningful analysis.

{
  "Expression": "nfc_hci_create_pipe",
  "PathPrefix": "net/nfc"
}

{
  "Output": "net/nfc/hci/command.c=202=static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)\n--\nnet/nfc/hci/command.c-207-\nnet/nfc/hci/command.c:208:static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,\nnet/nfc/hci/command.c-209-\t\t\t      u8 dest_gate, int *result)\n--\nnet/nfc/hci/command.c=306=int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,\n--\nnet/nfc/hci/command.c-328-\tdefault:\nnet/nfc/hci/command.c:329:\t\tpipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, \u0026r);\nnet/nfc/hci/command.c-330-\t\tif (pipe == NFC_HCI_INVALID_PIPE)\n"
}

gemini-3.8-flash

null

null

							input: 3904
							output: 38
							thoughts: 20
						

Here's a breakdown of my thought process:

**Diving into `nfc_hci_connect_gate` and `pipe`**

Alright, let's dissect this. My primary focus is on understanding the interaction between `nfc_hci_connect_gate` and `pipe`. I need to figure out how `pipe` is used within that function. I'm assuming, given the context, that `nfc_hci_connect_gate` likely handles some form of connection establishment or gatekeeping related to an NFC interface, potentially using the `pipe` as a communication channel or data structure. My immediate goals are to determine:

*   What is the specific role of `pipe` in the function? Is it a data structure, a file descriptor, or something else entirely?
*   How does `nfc_hci_connect_gate` utilize this `pipe` for connection establishment or management? Does it write to it, read from it, or both?
*   Are there any potential error conditions or race conditions related to the `pipe`'s usage?
*   What's the overall flow, specifically around how the `pipe` impacts the connection flow?
*   How could the understanding of this interaction be used for optimization, security, or debugging?

I'll be looking for clues in the function's code, likely checking for data transfers, synchronization mechanisms, and error handling related to the `pipe`. This might involve looking at buffer sizes, read/write operations, and any mutexes or semaphores that might be involved. The specific API calls used on the `pipe` will give me a clear picture of its functionality. I'm going to pay close attention to the data types associated with `pipe` as they'll provide strong context on the flow and purpose of the communication within this function.

{
  "File": "net/nfc/hci/command.c",
  "FirstLine": 305,
  "LineCount": 45
}

{
  "Contents": " 305:\t\n 306:\tint nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,\n 307:\t\t\t\t u8 pipe)\n 308:\t{\n 309:\t\tbool pipe_created = false;\n 310:\t\tint r;\n 311:\t\n 312:\t\tif (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)\n 313:\t\t\treturn 0;\n 314:\t\n 315:\t\tif (hdev-\u003egate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)\n 316:\t\t\treturn -EADDRINUSE;\n 317:\t\n 318:\t\tif (pipe != NFC_HCI_INVALID_PIPE)\n 319:\t\t\tgoto open_pipe;\n 320:\t\n 321:\t\tswitch (dest_gate) {\n 322:\t\tcase NFC_HCI_LINK_MGMT_GATE:\n 323:\t\t\tpipe = NFC_HCI_LINK_MGMT_PIPE;\n 324:\t\t\tbreak;\n 325:\t\tcase NFC_HCI_ADMIN_GATE:\n 326:\t\t\tpipe = NFC_HCI_ADMIN_PIPE;\n 327:\t\t\tbreak;\n 328:\t\tdefault:\n 329:\t\t\tpipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, \u0026r);\n 330:\t\t\tif (pipe == NFC_HCI_INVALID_PIPE)\n 331:\t\t\t\treturn r;\n 332:\t\t\tpipe_created = true;\n 333:\t\t\tbreak;\n 334:\t\t}\n 335:\t\n 336:\topen_pipe:\n 337:\t\tr = nfc_hci_open_pipe(hdev, pipe);\n 338:\t\tif (r \u003c 0) {\n 339:\t\t\tif (pipe_created)\n 340:\t\t\t\tif (nfc_hci_delete_pipe(hdev, pipe) \u003c 0) {\n 341:\t\t\t\t\t/* TODO: Cannot clean by deleting pipe...\n 342:\t\t\t\t\t * -\u003e inconsistent state */\n 343:\t\t\t\t}\n 344:\t\t\treturn r;\n 345:\t\t}\n 346:\t\n 347:\t\thdev-\u003epipes[pipe].gate = dest_gate;\n 348:\t\thdev-\u003epipes[pipe].dest_host = dest_host;\n 349:\t\thdev-\u003egate2pipe[dest_gate] = pipe;\n"
}

gemini-3.8-flash

null

null

							input: 5016
							output: 32
							thoughts: 344
						

**Analyzing the Patch for Potential Vulnerabilities**

Okay, let's break down this patch. I see they're handling a response to a "create pipe" request, which is common in NFC HCI communication. My immediate concern is always with memory safety and potential out-of-bounds reads or writes. I need to make sure this code is robust.

Before the patch, I can see a couple of issues. The code was vulnerable to a couple of scenarios. Firstly, if the received SKB (Socket Buffer) `skb->len` was smaller than the expected size of the response struct `sizeof(*resp)`. Without this check, the code would be attempting to read data from `skb->data` as if it contained the complete `hci_create_pipe_resp` struct. This is a classic out-of-bounds read vulnerability. The read `resp->pipe` could lead to reading past the end of the `skb->data` buffer, which is a big no-no and could crash or leak information. This is now fixed, of course.

Secondly, I'm spotting a potential index-out-of-bounds issue. The code later uses the `pipe` value, obtained from the response, as an index into the `hdev->pipes` array within the `nfc_hci_connect_gate` function. Without the check, if `pipe >= NFC_HCI_MAX_PIPES`, that would also lead to out-of-bounds array access. Fortunately, that's now also been fixed in this patch.

So, this patch appears to be addressing both of those vulnerabilities, which is good. We now have two checks: one for the SKB length and one for the pipe index. The patch adds the necessary checks to free the skb if there is an error, and returns an error code. 

{
  "Expression": "pipes\\[",
  "PathPrefix": "include/net/nfc/hci.h"
}

{
  "Output": "include/net/nfc/hci.h=99=struct nfc_hci_dev {\n--\ninclude/net/nfc/hci.h-129-\tu8 gate2pipe[NFC_HCI_MAX_GATES];\ninclude/net/nfc/hci.h:130:\tstruct nfc_hci_pipe pipes[NFC_HCI_MAX_PIPES];\ninclude/net/nfc/hci.h-131-\n"
}

gemini-3.8-flash

null

null

							input: 5904
							output: 204
							thoughts: 1041
						

**KMSAN Assessment: No Need for KMSAN**

Okay, let's break this down. My initial assessment immediately flagged potential out-of-bounds access, specifically a read from `skb->data` if the response was truncated and a write to `hdev->pipes[pipe]` if the pipe index was out of bounds. The code clearly addresses these issues.

The patch includes checks. First, it makes sure `skb->len` is large enough, checking if it is at least `sizeof(*resp)` before reading `resp->pipe` – thus preventing an out-of-bounds read of `resp->pipe`. Second, it confirms that `pipe` is within valid bounds (`pipe < NFC_HCI_MAX_PIPES`) before it writes to `hdev->pipes[pipe]`. This stops a potential out-of-bounds write.

Now, the crucial question: does this introduce any *uninitialized memory* vulnerabilities? I went through the relevant variables: `result`, `skb`, `resp`, and the logic in `nfc_hci_create_pipe()`. `nfc_hci_execute_cmd()` handles allocation of `skb`. The `resp` pointer is derived from `skb->data`, and its use is bounded by the size check. There's no data being sent to userspace. There's no conditional logic depending on potentially uninitialized values. Everything is properly initialized before use.

These are *classic* spatial memory safety issues—out-of-bounds reads and writes—which are precisely what KASAN is designed to catch. It will detect the OOB read of the `skb` heap buffer if `skb->len` is too small, and the OOB write to `hdev->pipes`.

Therefore, the patch does not introduce any:

*   Uninitialized memory reads.
*   Info leaks.
*   Kernel structures sent to userspace with uninitialized fields.
*   Uninitialized padding.
*   Uninitialized stack/heap variables.

Given the rule to avoid KMSAN if a bug can be caught by KASAN or other standard detectors, let's be crystal clear:

1.  **Patch Functionality:** The patch adds validation checks within `nfc_hci_create_pipe()` to safeguard against out-of-bounds access. It checks the size of `skb` and the `pipe` index.
2.  **KASAN vs. KMSAN:** The bugs being addressed are *spatial* memory errors. Specifically, out-of-bounds buffer reads from the `skb` heap buffer and writes to the `hdev->pipes` array. KASAN is well-suited to detect these. KMSAN is for detecting the use of *uninitialized* memory, something that this patch does not introduce.
3.  **Conclusion:** I conclude that this patch does *not* require KMSAN. The code fixes issues that KASAN should be able to handle, and no uninitialized memory risks are introduced by the changes.

{
  "KMSANReasoning": "The patch adds validation checks in `nfc_hci_create_pipe()`:\n1. It verifies that `skb-\u003elen \u003e= sizeof(*resp)` before dereferencing `resp-\u003epipe`, preventing an out-of-bounds read on a truncated skb buffer.\n2. It verifies that `pipe \u003c NFC_HCI_MAX_PIPES`, preventing an out-of-bounds array indexing bug when `hdev-\u003epipes[pipe]` is subsequently accessed in `nfc_hci_connect_gate()`.\n\nThese issues are classical out-of-bounds read/write memory safety vulnerabilities that are detected by KASAN. The patch does not introduce or modify any uninitialized variables, stack/heap allocations, padding bytes, or user-space copies (info-leaks). Therefore, a dedicated KMSAN fuzzing session is not warranted.",
  "NeedsKMSAN": false
}

{
  "KMSANReasoning": "The patch adds validation checks in `nfc_hci_create_pipe()`:\n1. It verifies that `skb-\u003elen \u003e= sizeof(*resp)` before dereferencing `resp-\u003epipe`, preventing an out-of-bounds read on a truncated skb buffer.\n2. It verifies that `pipe \u003c NFC_HCI_MAX_PIPES`, preventing an out-of-bounds array indexing bug when `hdev-\u003epipes[pipe]` is subsequently accessed in `nfc_hci_connect_gate()`.\n\nThese issues are classical out-of-bounds read/write memory safety vulnerabilities that are detected by KASAN. The patch does not introduce or modify any uninitialized variables, stack/heap allocations, padding bytes, or user-space copies (info-leaks). Therefore, a dedicated KMSAN fuzzing session is not warranted.",
  "NeedsKMSAN": false
}