AI Trajectory

Trajectory: (Expand/Collapse All)
Seq	Timestamp	Type	Name	Duration
0/0	2026/09/27 14:15	flow	patch-triage	2m Args: null Results: { "EnableConfigs": [ "NFC" ], "FocusSymbols": [ "llcp_sock_connect" ], "KMSANReasoning": "The patch modifies `llcp_sock_connect()` in `net/nfc/llcp_sock.c` to release retained resources (such as dropped device/local references, SSAP, and service name memory) when reconnecting a socket in the `LLCP_CLOSED` state.\n\n1. KMSAN applicability: The changes only free allocated resources (`kfree`, `nfc_put_device`, `nfc_llcp_local_put`, `nfc_llcp_put_ssap`) and reset pointer and integer fields on the socket struct (`local`, `dev`, `service_name`, `service_name_len`, `reserved_ssap`). No new uninitialized stack or heap allocations are introduced, no uninitialized variables or struct padding are read or branched on, and no data is copied to user space.\n2. KASAN and standard sanitizers: The bugs potentially associated with this cleanup logic involve refcounting errors, double-frees, or use-after-free conditions on the socket/device structures, which are detected by KASAN, refcount tracking, or standard kernel debuggers.\n\nTherefore, a dedicated KMSAN fuzzing session is not warranted.", "NeedsKMSAN": false, "Reasoning": "The patch modifies resource cleanup logic in llcp_sock_connect() for NFC LLCP sockets when transitioning or reconnecting from LLCP_CLOSED state. This reachable network socket path is accessible from unprivileged userspace via the AF_NFC socket API and warrants fuzzing for potential refcount bugs, double-frees, or state management issues.", "WorthFuzzing": true }
1/1	2026/09/27 14:15	action	read-patch-diff	0m Args: null Results: { "PatchDiff": "commit cc5b0edd1f67a160a2ff81be680294718ecd25df\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Sun Sep 27 14:15:43 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c\nindex 5558d8a4d48b3..e76361e5ef166 100644\n--- a/net/nfc/llcp_sock.c\n+++ b/net/nfc/llcp_sock.c\n@@ -690,6 +690,23 @@ static int llcp_sock_connect(struct socket sock, struct sockaddr_unsized _addr\n \t\tgoto error;\n \t}\n \n+\tif (sk-\u003esk_state == LLCP_CLOSED) {\n+\t\t/* Release resources retained by a previous failed connection. */\n+\t\tif (llcp_sock-\u003elocal) {\n+\t\t\tif (llcp_sock-\u003ereserved_ssap \u003c LLCP_SAP_MAX)\n+\t\t\t\tnfc_llcp_put_ssap(llcp_sock-\u003elocal, llcp_sock-\u003essap);\n+\t\t\tnfc_llcp_local_put(llcp_sock-\u003elocal);\n+\t\t}\n+\t\tif (llcp_sock-\u003edev)\n+\t\t\tnfc_put_device(llcp_sock-\u003edev);\n+\t\tkfree(llcp_sock-\u003eservice_name);\n+\t\tllcp_sock-\u003elocal = NULL;\n+\t\tllcp_sock-\u003edev = NULL;\n+\t\tllcp_sock-\u003eservice_name = NULL;\n+\t\tllcp_sock-\u003eservice_name_len = 0;\n+\t\tllcp_sock-\u003ereserved_ssap = LLCP_SAP_MAX;\n+\t}\n+\n \tdev = nfc_get_device(addr-\u003edev_idx);\n \tif (dev == NULL) {\n \t\tret = -ENODEV;\n" }
2/1	2026/09/27 14:15	agent	patch-evaluator	1m Model: core Args: null Results: { "EnableConfigs": [ "NFC" ], "FocusSymbols": [ "llcp_sock_connect" ], "Reasoning": "The patch modifies resource cleanup logic in llcp_sock_connect() for NFC LLCP sockets when transitioning or reconnecting from LLCP_CLOSED state. This reachable network socket path is accessible from unprivileged userspace via the AF_NFC socket API and warrants fuzzing for potential refcount bugs, double-frees, or state management issues.", "WorthFuzzing": true } Instruction: 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. Prompt: Target architecture: amd64 For your convenience, here is the diff of the changes: commit cc5b0edd1f67a160a2ff81be680294718ecd25df Author: syz-cluster <triage@syzkaller.com> Date: Sun Sep 27 14:15:43 2026 +0000 syz-cluster: applied patch under review diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index 5558d8a4d48b3..e76361e5ef166 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -690,6 +690,23 @@ static int llcp_sock_connect(struct socket sock, struct sockaddr_unsized _addr goto error; } + if (sk->sk_state == LLCP_CLOSED) { + /* Release resources retained by a previous failed connection. */ + if (llcp_sock->local) { + if (llcp_sock->reserved_ssap < LLCP_SAP_MAX) + nfc_llcp_put_ssap(llcp_sock->local, llcp_sock->ssap); + nfc_llcp_local_put(llcp_sock->local); + } + if (llcp_sock->dev) + nfc_put_device(llcp_sock->dev); + kfree(llcp_sock->service_name); + llcp_sock->local = NULL; + llcp_sock->dev = NULL; + llcp_sock->service_name = NULL; + llcp_sock->service_name_len = 0; + llcp_sock->reserved_ssap = LLCP_SAP_MAX; + } + dev = nfc_get_device(addr->dev_idx); if (dev == NULL) { ret = -ENODEV;
3/2	2026/09/27 14:15	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 3084 output: 39 thoughts: 474 Thoughts: Analyzing the LLCP Socket Connection Patch Okay, so I've got a patch here for the Linux kernel, specifically targeting the `net/nfc/llcp_sock.c` file. The architecture is amd64, which is relevant for the instruction set and memory model assumptions. Let's see what's being modified. The diff introduces a state check within the `llcp_sock_connect` function. The key here is the addition of `if (sk->sk_state == LLCP_CLOSED)`. My immediate thought is, this is probably aimed at resource cleanup in the face of a failed connection attempt. That looks like a good assumption to make given the context of a socket connect implementation. Inside that conditional, we have a series of checks and resource releases. It seems this code block is executed when the socket is in the `LLCP_CLOSED` state, which is significant. Let's break it down: * Local Resources: It checks if `llcp_sock->local` is valid, and if so, frees the corresponding SSAP (Service Specific Access Point) and releases the local LLCP context. * Device Resources: It also checks and releases `llcp_sock->dev` with `nfc_put_device` if a NFC device is associated. * String Resources: Finally, it frees the `service_name` string and resets the relevant fields (`local`, `dev`, `service_name`, and related lengths/flags) to NULL or default values. `reserved_ssap` is set to `LLCP_SAP_MAX`. This is an important detail. It essentially resets the state to an "uninitialized" state for the socket. The intention seems to be robust handling of resources after a failed connection. This suggests it's likely a fix for a potential memory leak or resource exhaustion issue. The `LLCP_CLOSED` state is a bit of a clue -- the previous connection likely failed, and these resources weren't properly cleaned up. A socket in a CLOSED state shouldn't be holding onto references to the underlying NFC device, SSAPs, or service name. Without this patch, these might be retained. I need to see how the connection process is being handled in order to evaluate this fully. My next step is to examine the surrounding code and possibly related functions to fully understand the connection lifecycle and identify potential race conditions or resource management issues. I'll pay close attention to error paths and how the socket transitions between states. I'd like to understand what leads to this LLCP_CLOSED state, as it suggests the failure mode of the socket is worth investigating. A good review of error handling in that code section should illuminate the need for this patch.
4/2	2026/09/27 14:16	tool	read-file	0m Args: { "File": "net/nfc/llcp_sock.c", "FirstLine": 670, "LineCount": 70 } Results: { "Contents": " 670:\t\n 671:\t\tpr_debug(\"sock %p sk %p flags 0x%x\\n\", sock, sk, flags);\n 672:\t\n 673:\t\tif (!addr \|\| len \u003c sizeof(addr) \|\| addr-\u003esa_family != AF_NFC)\n 674:\t\t\treturn -EINVAL;\n 675:\t\n 676:\t\tif (addr-\u003eservice_name_len == 0 \u0026\u0026 addr-\u003edsap == 0)\n 677:\t\t\treturn -EINVAL;\n 678:\t\n 679:\t\tpr_debug(\"addr dev_idx=%u target_idx=%u protocol=%u\\n\", addr-\u003edev_idx,\n 680:\t\t\t addr-\u003etarget_idx, addr-\u003enfc_protocol);\n 681:\t\n 682:\t\tlock_sock(sk);\n 683:\t\n 684:\t\tif (sk-\u003esk_state == LLCP_CONNECTED) {\n 685:\t\t\tret = -EISCONN;\n 686:\t\t\tgoto error;\n 687:\t\t}\n 688:\t\tif (sk-\u003esk_state == LLCP_CONNECTING) {\n 689:\t\t\tret = -EINPROGRESS;\n 690:\t\t\tgoto error;\n 691:\t\t}\n 692:\t\n 693:\t\tif (sk-\u003esk_state == LLCP_CLOSED) {\n 694:\t\t\t/ Release resources retained by a previous failed connection. */\n 695:\t\t\tif (llcp_sock-\u003elocal) {\n 696:\t\t\t\tif (llcp_sock-\u003ereserved_ssap \u003c LLCP_SAP_MAX)\n 697:\t\t\t\t\tnfc_llcp_put_ssap(llcp_sock-\u003elocal, llcp_sock-\u003essap);\n 698:\t\t\t\tnfc_llcp_local_put(llcp_sock-\u003elocal);\n 699:\t\t\t}\n 700:\t\t\tif (llcp_sock-\u003edev)\n 701:\t\t\t\tnfc_put_device(llcp_sock-\u003edev);\n 702:\t\t\tkfree(llcp_sock-\u003eservice_name);\n 703:\t\t\tllcp_sock-\u003elocal = NULL;\n 704:\t\t\tllcp_sock-\u003edev = NULL;\n 705:\t\t\tllcp_sock-\u003eservice_name = NULL;\n 706:\t\t\tllcp_sock-\u003eservice_name_len = 0;\n 707:\t\t\tllcp_sock-\u003ereserved_ssap = LLCP_SAP_MAX;\n 708:\t\t}\n 709:\t\n 710:\t\tdev = nfc_get_device(addr-\u003edev_idx);\n 711:\t\tif (dev == NULL) {\n 712:\t\t\tret = -ENODEV;\n 713:\t\t\tgoto error;\n 714:\t\t}\n 715:\t\n 716:\t\tlocal = nfc_llcp_find_local(dev);\n 717:\t\tif (local == NULL) {\n 718:\t\t\tret = -ENODEV;\n 719:\t\t\tgoto put_dev;\n 720:\t\t}\n 721:\t\n 722:\t\tdevice_lock(\u0026dev-\u003edev);\n 723:\t\tif (dev-\u003edep_link_up == false) {\n 724:\t\t\tret = -ENOLINK;\n 725:\t\t\tdevice_unlock(\u0026dev-\u003edev);\n 726:\t\t\tgoto sock_llcp_put_local;\n 727:\t\t}\n 728:\t\tdevice_unlock(\u0026dev-\u003edev);\n 729:\t\n 730:\t\tif (local-\u003erf_mode == NFC_RF_INITIATOR \u0026\u0026\n 731:\t\t addr-\u003etarget_idx != local-\u003etarget_idx) {\n 732:\t\t\tret = -ENOLINK;\n 733:\t\t\tgoto sock_llcp_put_local;\n 734:\t\t}\n 735:\t\n 736:\t\tllcp_sock-\u003edev = dev;\n 737:\t\tllcp_sock-\u003elocal = local;\n 738:\t\tllcp_sock-\u003essap = nfc_llcp_get_local_ssap(local);\n 739:\t\tif (llcp_sock-\u003essap == LLCP_SAP_MAX) {\n" }
5/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 5271 output: 39 thoughts: 13 Thoughts: Okay, here's my take on those thoughts, tailored for an expert audience: Diving into the Net/NFC Kconfig Alright, let's get down to brass tacks. I need to understand the configuration landscape for the NFC subsystem. My immediate thought is, "Right, Kconfig in `net/nfc` is the key." I need to understand what's controllable, what dependencies exist, and how it all hangs together. I’m thinking about quickly grasping the options available: Is this a modular implementation? Are there specific NFC controller drivers that are required or optional? How is the core NFC stack interwoven with other networking functionalities in the kernel? I need to quickly ascertain the build configuration possibilities to determine what's possible and what's enabled by default. Is there a clear hierarchy or a spaghetti of dependencies in there? Let's get cracking, and see what the build system is allowing us to do.
6/2	2026/09/27 14:16	tool	grepper	0m Error: no matches Args: { "Expression": "obj-\\$\$CONFIG_.\$ += llcp_sock.o", "PathPrefix": "net/nfc" } Results:* { "error": "no matches" }
7/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 5532 output: 32 thoughts: 12 Thoughts: Okay, here's my take on those thoughts, tailored for an expert audience: Diving into the NFC Makefile Alright, time to get granular. Based on the context, I'm thinking the logical first step is to dive into the `net/nfc/Makefile`. That's where I'll likely find the core build definitions and dependencies for the NFC subsystem. This is the central repository to understand how the various components are compiled, linked, and ultimately integrated into the broader kernel build. I'm going to look for things like: * The source file list for the NFC driver modules. * Compilation flags and optimization levels specific to NFC. * Target architecture-specific directives. * Dependency tracking, especially how NFC interacts with other kernel subsystems like networking, power management, or hardware abstraction layers. * Any conditional build logic based on kernel configuration options (`CONFIG_`). Essentially, my goal is to get a solid grasp of the NFC subsystem's build process to understand how it is put together. This is the starting point for any in-depth investigation.
8/2	2026/09/27 14:16	tool	read-file	0m Args: { "File": "net/nfc/Makefile", "FirstLine": 1, "LineCount": 40 } Results: { "Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0\n 2:\t#\n 3:\t# Makefile for the Linux NFC subsystem.\n 4:\t#\n 5:\t\n 6:\tobj-$(CONFIG_NFC) += nfc.o\n 7:\tobj-$(CONFIG_NFC_NCI) += nci/\n 8:\tobj-$(CONFIG_NFC_HCI) += hci/\n 9:\tobj-$(CONFIG_NFC_DIGITAL) += nfc_digital.o\n 10:\t\n 11:\tnfc-objs := core.o netlink.o af_nfc.o rawsock.o llcp_core.o llcp_commands.o \\\n 12:\t\t\tllcp_sock.o\n 13:\t\n 14:\tnfc_digital-objs := digital_core.o digital_technology.o digital_dep.o\n" }
9/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 6040 output: 33 thoughts: 37 Thoughts: Okay, here's my interpretation of that thought process, from an expert's perspective: Diving into the NFC Kernel Configuration Alright, so `CONFIG_NFC` is building the `nfc.o` object file. Interesting. And I see that `llcp_sock.o` is included within that. My mind immediately jumps to verifying the configuration dependencies and ensuring everything's in order, so I need to check the `net/nfc/Kconfig` file. I need to understand exactly how `CONFIG_NFC` is defined, what its dependencies are, and whether `llcp_sock.o` is conditionally compiled based on other options. This will help me understand what features are enabled and disabled based on the system configuration. It's all about ensuring that the configuration logic is sound and that the resulting kernel image includes only the necessary components, while also ensuring that all dependencies are accounted for. Time to dig in and confirm my assumptions.
10/2	2026/09/27 14:16	tool	read-file	0m Args: { "File": "net/nfc/Kconfig", "FirstLine": 1, "LineCount": 40 } Results: { "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" }
11/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 6730 output: 30 thoughts: 102 Thoughts: NFC Kernel Configuration and Socket Connectivity Okay, so I'm looking at this kernel configuration dependency: `menuconfig NFC` depends on `RFKILL \|\| !RFKILL`. That makes sense. Now, my immediate question is, can I actually reach NFC LLCP sockets from userspace? I seem to recall that you can use sockets... Yes, I can use the standard socket API. Specifically, `socket(AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP)` or even `SOCK_DGRAM`, or perhaps even raw sockets. That's good. Now, I need to get into the details to understand how `AF_NFC` sockets are created and how `llcp_sock_connect` is called. I'm going to dive right into `llcp_sock.c` to trace the connection. I need to get a clear picture of the whole process.
12/2	2026/09/27 14:16	tool	grepper	0m Args: { "Expression": "llcp_sock_connect", "PathPrefix": "net/nfc" } Results: { "Output": "net/nfc/llcp_sock.c=602=static int llcp_sock_release(struct socket sock)\n--\nnet/nfc/llcp_sock.c-660-\nnet/nfc/llcp_sock.c:661:static int llcp_sock_connect(struct socket sock, struct sockaddr_unsized *_addr,\nnet/nfc/llcp_sock.c-662-\t\t\t int len, int flags)\n--\nnet/nfc/llcp_sock.c=944=static const struct proto_ops llcp_sock_ops = {\n--\nnet/nfc/llcp_sock.c-947-\t.bind = llcp_sock_bind,\nnet/nfc/llcp_sock.c:948:\t.connect = llcp_sock_connect,\nnet/nfc/llcp_sock.c-949-\t.release = llcp_sock_release,\n" }
13/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 7301 output: 39 thoughts: 66 Thoughts: Okay, let's see... LLCP Socket Operation Review Right, so `llcp_sock_ops` definitely has its `.connect` function pointing to `llcp_sock_connect`. Standard stuff. But I'm also curious about the raw socket operations, or possibly the stream/dgram socket operations. I seem to recall we handle things differently in that area. Let me quickly check the implementation details in `net/nfc/llcp_sock.c`, specifically around lines 940 to 1000. That should give me a refresher and help solidify what the overall pattern is in this section of the code. I need to make sure I am accounting for everything.
14/2	2026/09/27 14:16	tool	read-file	0m Args: { "File": "net/nfc/llcp_sock.c", "FirstLine": 940, "LineCount": 60 } Results: { "Contents": " 940:\t\n 941:\t\treturn copied;\n 942:\t}\n 943:\t\n 944:\tstatic const struct proto_ops llcp_sock_ops = {\n 945:\t\t.family = PF_NFC,\n 946:\t\t.owner = THIS_MODULE,\n 947:\t\t.bind = llcp_sock_bind,\n 948:\t\t.connect = llcp_sock_connect,\n 949:\t\t.release = llcp_sock_release,\n 950:\t\t.socketpair = sock_no_socketpair,\n 951:\t\t.accept = llcp_sock_accept,\n 952:\t\t.getname = llcp_sock_getname,\n 953:\t\t.poll = llcp_sock_poll,\n 954:\t\t.ioctl = sock_no_ioctl,\n 955:\t\t.listen = llcp_sock_listen,\n 956:\t\t.shutdown = sock_no_shutdown,\n 957:\t\t.setsockopt = nfc_llcp_setsockopt,\n 958:\t\t.getsockopt = nfc_llcp_getsockopt,\n 959:\t\t.sendmsg = llcp_sock_sendmsg,\n 960:\t\t.recvmsg = llcp_sock_recvmsg,\n 961:\t\t.mmap = sock_no_mmap,\n 962:\t};\n 963:\t\n 964:\tstatic const struct proto_ops llcp_rawsock_ops = {\n 965:\t\t.family = PF_NFC,\n 966:\t\t.owner = THIS_MODULE,\n 967:\t\t.bind = llcp_raw_sock_bind,\n 968:\t\t.connect = sock_no_connect,\n 969:\t\t.release = llcp_sock_release,\n 970:\t\t.socketpair = sock_no_socketpair,\n 971:\t\t.accept = sock_no_accept,\n 972:\t\t.getname = llcp_sock_getname,\n 973:\t\t.poll = llcp_sock_poll,\n 974:\t\t.ioctl = sock_no_ioctl,\n 975:\t\t.listen = sock_no_listen,\n 976:\t\t.shutdown = sock_no_shutdown,\n 977:\t\t.sendmsg = sock_no_sendmsg,\n 978:\t\t.recvmsg = llcp_sock_recvmsg,\n 979:\t\t.mmap = sock_no_mmap,\n 980:\t};\n 981:\t\n 982:\tstatic void llcp_sock_destruct(struct sock sk)\n 983:\t{\n 984:\t\tstruct nfc_llcp_sock llcp_sock = nfc_llcp_sock(sk);\n 985:\t\n 986:\t\tpr_debug(\"%p\\n\", sk);\n 987:\t\n 988:\t\tif (sk-\u003esk_state == LLCP_CONNECTED)\n 989:\t\t\tnfc_put_device(llcp_sock-\u003edev);\n 990:\t\n 991:\t\tskb_queue_purge(\u0026sk-\u003esk_receive_queue);\n 992:\t\n 993:\t\tnfc_llcp_sock_free(llcp_sock);\n 994:\t\n 995:\t\tif (!sock_flag(sk, SOCK_DEAD)) {\n 996:\t\t\tpr_err(\"Freeing alive NFC LLCP socket %p\\n\", sk);\n 997:\t\t\treturn;\n 998:\t\t}\n 999:\t}\n" }
15/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 8527 output: 39 thoughts: 290 Thoughts: Analyzing the LLCP Socket Connection Process Okay, so `llcp_sock_ops` is definitely the handler for connect operations on AF_NFC LLCP sockets. Time to dig into this patch and see what's going on. Focusing on `llcp_sock_connect` specifically, it looks like there's a critical check at the beginning. It's handling a connection attempt, and the first thing it does is verify the socket's state is `LLCP_CLOSED`. Makes sense - it’s probably cleaning up from a previous, possibly failed connection. I see it's releasing resources if the socket was previously in a failed connection. Specifically, it seems to be releasing the local LLCP entity (`llcp_sock->local`), which might have held an assigned SAP. If a SAP was reserved in the past, it's released back to the local device using `nfc_llcp_put_ssap`. It also calls `nfc_llcp_local_put` to release the local entity entirely. It also decrements the device reference, frees any previously allocated service name, and resets all associated variables to NULL or default values. A really comprehensive cleanup. Alright, I'll go through the rest of `llcp_sock_connect` and the associated error handling to get the full picture.
16/2	2026/09/27 14:16	tool	read-file	0m Args: { "File": "net/nfc/llcp_sock.c", "FirstLine": 730, "LineCount": 70 } Results: { "Contents": " 730:\t\tif (local-\u003erf_mode == NFC_RF_INITIATOR \u0026\u0026\n 731:\t\t addr-\u003etarget_idx != local-\u003etarget_idx) {\n 732:\t\t\tret = -ENOLINK;\n 733:\t\t\tgoto sock_llcp_put_local;\n 734:\t\t}\n 735:\t\n 736:\t\tllcp_sock-\u003edev = dev;\n 737:\t\tllcp_sock-\u003elocal = local;\n 738:\t\tllcp_sock-\u003essap = nfc_llcp_get_local_ssap(local);\n 739:\t\tif (llcp_sock-\u003essap == LLCP_SAP_MAX) {\n 740:\t\t\tret = -ENOMEM;\n 741:\t\t\tgoto sock_llcp_nullify;\n 742:\t\t}\n 743:\t\n 744:\t\tllcp_sock-\u003ereserved_ssap = llcp_sock-\u003essap;\n 745:\t\n 746:\t\tif (addr-\u003eservice_name_len == 0)\n 747:\t\t\tllcp_sock-\u003edsap = addr-\u003edsap;\n 748:\t\telse\n 749:\t\t\tllcp_sock-\u003edsap = LLCP_SAP_SDP;\n 750:\t\tllcp_sock-\u003enfc_protocol = addr-\u003enfc_protocol;\n 751:\t\tllcp_sock-\u003eservice_name_len = min_t(unsigned int,\n 752:\t\t\t\t\t\t addr-\u003eservice_name_len,\n 753:\t\t\t\t\t\t NFC_LLCP_MAX_SERVICE_NAME);\n 754:\t\tllcp_sock-\u003eservice_name = kmemdup(addr-\u003eservice_name,\n 755:\t\t\t\t\t\t llcp_sock-\u003eservice_name_len,\n 756:\t\t\t\t\t\t GFP_KERNEL);\n 757:\t\tif (!llcp_sock-\u003eservice_name) {\n 758:\t\t\tret = -ENOMEM;\n 759:\t\t\tgoto sock_llcp_release;\n 760:\t\t}\n 761:\t\n 762:\t\tnfc_llcp_sock_link(\u0026local-\u003econnecting_sockets, sk);\n 763:\t\n 764:\t\tret = nfc_llcp_send_connect(llcp_sock);\n 765:\t\tif (ret)\n 766:\t\t\tgoto sock_unlink;\n 767:\t\n 768:\t\tsk-\u003esk_state = LLCP_CONNECTING;\n 769:\t\n 770:\t\tret = sock_wait_state(sk, LLCP_CONNECTED,\n 771:\t\t\t\t sock_sndtimeo(sk, flags \u0026 O_NONBLOCK));\n 772:\t\tif (ret \u0026\u0026 ret != -EINPROGRESS)\n 773:\t\t\tgoto sock_unlink;\n 774:\t\n 775:\t\trelease_sock(sk);\n 776:\t\n 777:\t\treturn ret;\n 778:\t\n 779:\tsock_unlink:\n 780:\t\tnfc_llcp_sock_unlink(\u0026local-\u003econnecting_sockets, sk);\n 781:\t\tkfree(llcp_sock-\u003eservice_name);\n 782:\t\tllcp_sock-\u003eservice_name = NULL;\n 783:\t\n 784:\tsock_llcp_release:\n 785:\t\tnfc_llcp_put_ssap(local, llcp_sock-\u003essap);\n 786:\t\n 787:\tsock_llcp_nullify:\n 788:\t\tllcp_sock-\u003elocal = NULL;\n 789:\t\tllcp_sock-\u003edev = NULL;\n 790:\t\n 791:\tsock_llcp_put_local:\n 792:\t\tnfc_llcp_local_put(local);\n 793:\t\n 794:\tput_dev:\n 795:\t\tnfc_put_device(dev);\n 796:\t\n 797:\terror:\n 798:\t\trelease_sock(sk);\n 799:\t\treturn ret;\n" }
17/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 10202 output: 32 thoughts: 201 Thoughts: Okay, here's my assessment of this code snippet, keeping in mind my expertise: Potential Asynchronous Connection Issue in LLCP Alright, let's dissect this. My immediate concern is how the code handles connection failures, especially asynchronously. This `sock_wait_state` function is the key – specifically, the logic at line 772: ```c ret = sock_wait_state(sk, LLCP_CONNECTED, sock_sndtimeo(sk, flags & O_NONBLOCK)); if (ret && ret != -EINPROGRESS) goto sock_unlink; ``` If `ret` is `-EINPROGRESS`, we're dealing with a non-blocking connect call. The code returns without cleaning up or taking any failure actions! This is a red flag. Later, the connection might ultimately fail and the socket state transition to `LLCP_CLOSED`, or possibly, `connect` could be called again. The bigger worry is what happens then. If the socket state is `LLCP_CLOSED` when `connect` is called again, there's a good chance that critical data like `llcp_sock->local`, `dev`, `service_name`, etc., has been retained from the previous connection attempt. This screams potential memory leaks, use-after-free scenarios, double-puts, or other nasty race conditions. The code needs to handle the cleanup and state reset correctly on failure. I need to understand what state variables the code is relying on. I need to understand the intent of the author, and any related bug reports that may have been reported for this. Therefore, I'm going to pull up the git log for this commit to get the full context around this code, and verify what the intent was.
18/2	2026/09/27 14:16	tool	grepper	0m Args: { "Expression": "Release resources retained by a previous failed connection", "PathPrefix": "net/nfc" } Results: { "Output": "net/nfc/llcp_sock.c=661=static int llcp_sock_connect(struct socket sock, struct sockaddr_unsized _addr,\n--\nnet/nfc/llcp_sock.c-693-\tif (sk-\u003esk_state == LLCP_CLOSED) {\nnet/nfc/llcp_sock.c:694:\t\t/* Release resources retained by a previous failed connection. */\nnet/nfc/llcp_sock.c-695-\t\tif (llcp_sock-\u003elocal) {\n" }
19/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 10956 output: 37 thoughts: 222 Thoughts: Analyzing the NFC Context Okay, so I need to figure out the implications of this commit, `cc5b0edd1f67a160a2ff81be680294718ecd25df`, specifically regarding NFC support. I don't need to dive into `git log` or `git show` directly; the prompt already gives me the critical commit message: "syz-cluster: applied patch under review". My immediate thought is to determine if `net/nfc/llcp_sock.c` is even reachable in a typical syzkaller environment, whether that be QEMU or GCE. The key question is, does syzkaller even support NFC? Can it create virtual NFC devices for testing? I need to check the syzkaller definitions, or kernel drivers, to understand how NFC is emulated or supported within that framework. The presence of `syz_nfc_digital_make_dep` is a strong hint, but it might still require further investigation into virtual NFC/nfcsim or netlink nfc methods. And a fundamental question: Can userspace even open an AF_NFC socket? That's the real test, and if so, I will need to inspect the `af_nfc.c` code to ascertain the level of support in this environment.
20/2	2026/09/27 14:16	tool	read-file	0m Args: { "File": "net/nfc/af_nfc.c", "FirstLine": 1, "LineCount": 80 } Results: { "Contents": " 1:\t// SPDX-License-Identifier: GPL-2.0-or-later\n 2:\t/\n 3:\t Copyright (C) 2011 Instituto Nokia de Tecnologia\n 4:\t \n 5:\t Authors:\n 6:\t * Aloisio Almeida Jr \u003caloisio.almeida@openbossa.org\u003e\n 7:\t * Lauro Ramos Venancio \u003clauro.venancio@openbossa.org\u003e\n 8:\t /\n 9:\t\n 10:\t#include \u003clinux/nfc.h\u003e\n 11:\t#include \u003clinux/module.h\u003e\n 12:\t\n 13:\t#include \"nfc.h\"\n 14:\t\n 15:\tstatic DEFINE_RWLOCK(proto_tab_lock);\n 16:\tstatic const struct nfc_protocol proto_tab[NFC_SOCKPROTO_MAX];\n 17:\t\n 18:\tstatic int nfc_sock_create(struct net net, struct socket sock, int proto,\n 19:\t\t\t\t int kern)\n 20:\t{\n 21:\t\tint rc = -EPROTONOSUPPORT;\n 22:\t\n 23:\t\tif (net != \u0026init_net)\n 24:\t\t\treturn -EAFNOSUPPORT;\n 25:\t\n 26:\t\tif (proto \u003c 0 \|\| proto \u003e= NFC_SOCKPROTO_MAX)\n 27:\t\t\treturn -EINVAL;\n 28:\t\n 29:\t\tread_lock(\u0026proto_tab_lock);\n 30:\t\tif (proto_tab[proto] \u0026\u0026\ttry_module_get(proto_tab[proto]-\u003eowner)) {\n 31:\t\t\trc = proto_tab[proto]-\u003ecreate(net, sock, proto_tab[proto], kern);\n 32:\t\t\tmodule_put(proto_tab[proto]-\u003eowner);\n 33:\t\t}\n 34:\t\tread_unlock(\u0026proto_tab_lock);\n 35:\t\n 36:\t\treturn rc;\n 37:\t}\n 38:\t\n 39:\tstatic const struct net_proto_family nfc_sock_family_ops = {\n 40:\t\t.owner = THIS_MODULE,\n 41:\t\t.family = PF_NFC,\n 42:\t\t.create = nfc_sock_create,\n 43:\t};\n 44:\t\n 45:\tint nfc_proto_register(const struct nfc_protocol nfc_proto)\n 46:\t{\n 47:\t\tint rc;\n 48:\t\n 49:\t\tif (nfc_proto-\u003eid \u003c 0 \|\| nfc_proto-\u003eid \u003e= NFC_SOCKPROTO_MAX)\n 50:\t\t\treturn -EINVAL;\n 51:\t\n 52:\t\trc = proto_register(nfc_proto-\u003eproto, 0);\n 53:\t\tif (rc)\n 54:\t\t\treturn rc;\n 55:\t\n 56:\t\twrite_lock(\u0026proto_tab_lock);\n 57:\t\tif (proto_tab[nfc_proto-\u003eid])\n 58:\t\t\trc = -EBUSY;\n 59:\t\telse\n 60:\t\t\tproto_tab[nfc_proto-\u003eid] = nfc_proto;\n 61:\t\twrite_unlock(\u0026proto_tab_lock);\n 62:\t\n 63:\t\tif (rc)\n 64:\t\t\tproto_unregister(nfc_proto-\u003eproto);\n 65:\t\n 66:\t\treturn rc;\n 67:\t}\n 68:\tEXPORT_SYMBOL(nfc_proto_register);\n 69:\t\n 70:\tvoid nfc_proto_unregister(const struct nfc_protocol nfc_proto)\n 71:\t{\n 72:\t\twrite_lock(\u0026proto_tab_lock);\n 73:\t\tproto_tab[nfc_proto-\u003eid] = NULL;\n 74:\t\twrite_unlock(\u0026proto_tab_lock);\n 75:\t\n 76:\t\tproto_unregister(nfc_proto-\u003eproto);\n 77:\t}\n 78:\tEXPORT_SYMBOL(nfc_proto_unregister);\n 79:\t\n 80:\tint __init af_nfc_init(void)\n" }
21/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 12585 output: 40 thoughts: 48 Thoughts: Here's my analysis of the code registration process: AF_NFC and llcp_sock Registration: A Quick Look Okay, so `AF_NFC` is officially registered with the kernel using `sock_register(&nfc_sock_family_ops)`. That's the starting point. Now, I need to understand how the `llcp_sock` structure fits into this. Specifically, I'm diving into `llcp_sock.c` to see precisely how the `llcp_sock` is registered within this framework. Is it a specific implementation within the NFC family, or does it utilize the general socket registration somehow? I'm anticipating it's an important piece of the puzzle, and seeing how it gets plugged in will clarify the overall architecture of the NFC stack from a socket perspective. Let's see how that connection is established.
22/2	2026/09/27 14:16	tool	read-file	0m Args: { "File": "net/nfc/llcp_sock.c", "FirstLine": 1040, "LineCount": 60 } Results: { "Contents": "1040:\t\n1041:\t\tskb_queue_purge(\u0026sock-\u003etx_queue);\n1042:\t\tskb_queue_purge(\u0026sock-\u003etx_pending_queue);\n1043:\t\n1044:\t\tlist_del_init(\u0026sock-\u003eaccept_queue);\n1045:\t\n1046:\t\tsock-\u003eparent = NULL;\n1047:\t\n1048:\t\tnfc_llcp_local_put(sock-\u003elocal);\n1049:\t}\n1050:\t\n1051:\tstatic int llcp_sock_create(struct net net, struct socket sock,\n1052:\t\t\t\t const struct nfc_protocol nfc_proto, int kern)\n1053:\t{\n1054:\t\tstruct sock sk;\n1055:\t\n1056:\t\tpr_debug(\"%p\\n\", sock);\n1057:\t\n1058:\t\tif (sock-\u003etype != SOCK_STREAM \u0026\u0026\n1059:\t\t sock-\u003etype != SOCK_DGRAM \u0026\u0026\n1060:\t\t sock-\u003etype != SOCK_RAW)\n1061:\t\t\treturn -ESOCKTNOSUPPORT;\n1062:\t\n1063:\t\tif (sock-\u003etype == SOCK_RAW) {\n1064:\t\t\tif (!capable(CAP_NET_RAW))\n1065:\t\t\t\treturn -EPERM;\n1066:\t\t\tsock-\u003eops = \u0026llcp_rawsock_ops;\n1067:\t\t} else {\n1068:\t\t\tsock-\u003eops = \u0026llcp_sock_ops;\n1069:\t\t}\n1070:\t\n1071:\t\tsk = nfc_llcp_sock_alloc(sock, sock-\u003etype, GFP_ATOMIC, kern);\n1072:\t\tif (sk == NULL)\n1073:\t\t\treturn -ENOMEM;\n1074:\t\n1075:\t\treturn 0;\n1076:\t}\n1077:\t\n1078:\tstatic const struct nfc_protocol llcp_nfc_proto = {\n1079:\t\t.id\t = NFC_SOCKPROTO_LLCP,\n1080:\t\t.proto = \u0026llcp_sock_proto,\n1081:\t\t.owner = THIS_MODULE,\n1082:\t\t.create = llcp_sock_create\n1083:\t};\n1084:\t\n1085:\tint __init nfc_llcp_sock_init(void)\n1086:\t{\n1087:\t\treturn nfc_proto_register(\u0026llcp_nfc_proto);\n1088:\t}\n1089:\t\n1090:\tvoid nfc_llcp_sock_exit(void)\n1091:\t{\n1092:\t\tnfc_proto_unregister(\u0026llcp_nfc_proto);\n1093:\t}\n" }
23/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 13621 output: 33 thoughts: 398 Thoughts: LLCP Socket Connection: A Deep Dive Okay, so I see that `llcp_nfc_proto.id` is set to `NFC_SOCKPROTO_LLCP`. This immediately tells me that creating an LLCP socket involves calling `socket()` with `PF_NFC`, and either `SOCK_STREAM` or `SOCK_DGRAM`, crucially combined with `NFC_SOCKPROTO_LLCP`. Got it. That's the foundation. Now, a user in userspace is going to call `connect()` on this socket, and I'm guessing the provided `sockaddr_nfc_llcp` structure contains the connection details, as expected. This `connect()` call is the key to setting up the connection. Ah, and I see the `llcp_sock_ops.connect` is pointing to `llcp_sock_connect`. Perfect! Inside `llcp_sock_connect`, I'm carefully examining the code and I immediately notice a state check, specifically `sk->sk_state == LLCP_CLOSED`. This is an essential check. It looks like if the socket state is `LLCP_CLOSED`, which implies a previous failed connection, there's a significant cleanup operation performed to release resources. I see checks and releases related to the `llcp_sock->local`, `llcp_sock->dev`, and `llcp_sock->service_name`. This means the system properly manages and cleans up resources from a previous failed attempt. I like this. It avoids resource leaks. But, hang on a moment! I need to know something more fundamental to the context. What is the initial state of `sk->sk_state` when the socket is allocated? This is crucial to understanding the first connection attempt. I'll need to check the `nfc_llcp_sock_alloc` function to get a good handle on that.
24/2	2026/09/27 14:16	tool	grepper	0m Args: { "Expression": "nfc_llcp_sock_alloc", "PathPrefix": "net/nfc" } Results: { "Output": "net/nfc/llcp.h=210=void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local local,\n--\nnet/nfc/llcp.h-213-/ Sock API /\nnet/nfc/llcp.h:214:struct sock nfc_llcp_sock_alloc(struct socket sock, int type, gfp_t gfp, int kern);\nnet/nfc/llcp.h-215-void nfc_llcp_sock_free(struct nfc_llcp_sock sock);\n--\nnet/nfc/llcp_core.c=911=static void nfc_llcp_recv_connect(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-973-\nnet/nfc/llcp_core.c:974:\tnew_sk = nfc_llcp_sock_alloc(NULL, parent-\u003esk_type, GFP_ATOMIC, 0);\nnet/nfc/llcp_core.c-975-\tif (new_sk == NULL) {\n--\nnet/nfc/llcp_sock.c=982=static void llcp_sock_destruct(struct sock sk)\n--\nnet/nfc/llcp_sock.c-1000-\nnet/nfc/llcp_sock.c:1001:struct sock nfc_llcp_sock_alloc(struct socket sock, int type, gfp_t gfp, int kern)\nnet/nfc/llcp_sock.c-1002-{\n--\nnet/nfc/llcp_sock.c=1051=static int llcp_sock_create(struct net net, struct socket sock,\n--\nnet/nfc/llcp_sock.c-1070-\nnet/nfc/llcp_sock.c:1071:\tsk = nfc_llcp_sock_alloc(sock, sock-\u003etype, GFP_ATOMIC, kern);\nnet/nfc/llcp_sock.c-1072-\tif (sk == NULL)\n" }
25/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 14996 output: 40 thoughts: 37 Thoughts: Okay, let's dive into this. Here's how I'd approach that snippet of code, assuming my expertise in networking protocols: Analyzing the Allocation of an LLCP Socket Right, let's take a look at the `nfc_llcp_sock_alloc` implementation. The core of this function, the actual allocation logic, should be around line 1001 of `net/nfc/llcp_sock.c`. I need to understand how the system creates and initializes a new LLCP socket. I'll expect to see memory being allocated for a new socket structure, likely with `kmalloc` or similar, perhaps within a `slab` cache for efficiency. I'll be looking to see what data structures it's interacting with to manage the active sockets; probably a linked list or hash table, keeping track of them. The function should be setting up the basic socket state: initializing some default values for things like the protocol family (likely NFC, of course), the socket type (maybe SOCK_DGRAM or SOCK_SEQPACKET), and the protocol itself (LLCP). I'll want to see how it handles potential allocation failures – error handling is crucial for any low-level network code. A good implementation would also include initializing mutexes or spinlocks to ensure thread-safety, since this is in the kernel. Finally, I'll pay attention to any initialization or population of the socket's internal data structures, and how this new socket is then linked into the overall system. I'll be interested to see how it's integrated with the NFC stack. Is there a call to an NFC device driver or another important piece of the stack? This is where I'll get an understanding of the overall LLCP socket architecture. The specifics of the `nfc_llcp_sock` structure and how it's integrated with other LLCP parts are what I'm interested in here.
26/2	2026/09/27 14:16	tool	read-file	0m Args: { "File": "net/nfc/llcp_sock.c", "FirstLine": 1000, "LineCount": 40 } Results: { "Contents": "1000:\t\n1001:\tstruct sock nfc_llcp_sock_alloc(struct socket sock, int type, gfp_t gfp, int kern)\n1002:\t{\n1003:\t\tstruct sock sk;\n1004:\t\tstruct nfc_llcp_sock llcp_sock;\n1005:\t\n1006:\t\tsk = sk_alloc(\u0026init_net, PF_NFC, gfp, \u0026llcp_sock_proto, kern);\n1007:\t\tif (!sk)\n1008:\t\t\treturn NULL;\n1009:\t\n1010:\t\tllcp_sock = nfc_llcp_sock(sk);\n1011:\t\n1012:\t\tsock_init_data(sock, sk);\n1013:\t\tsk-\u003esk_state = LLCP_CLOSED;\n1014:\t\tsk-\u003esk_protocol = NFC_SOCKPROTO_LLCP;\n1015:\t\tsk-\u003esk_type = type;\n1016:\t\tsk-\u003esk_destruct = llcp_sock_destruct;\n1017:\t\n1018:\t\tllcp_sock-\u003essap = 0;\n1019:\t\tllcp_sock-\u003edsap = LLCP_SAP_SDP;\n1020:\t\tllcp_sock-\u003erw = LLCP_MAX_RW + 1;\n1021:\t\tllcp_sock-\u003emiux = cpu_to_be16(LLCP_MAX_MIUX + 1);\n1022:\t\tllcp_sock-\u003esend_n = llcp_sock-\u003esend_ack_n = 0;\n1023:\t\tllcp_sock-\u003erecv_n = llcp_sock-\u003erecv_ack_n = 0;\n1024:\t\tllcp_sock-\u003eremote_ready = 1;\n1025:\t\tllcp_sock-\u003ereserved_ssap = LLCP_SAP_MAX;\n1026:\t\tnfc_llcp_socket_remote_param_init(llcp_sock);\n1027:\t\tskb_queue_head_init(\u0026llcp_sock-\u003etx_queue);\n1028:\t\tskb_queue_head_init(\u0026llcp_sock-\u003etx_pending_queue);\n1029:\t\tINIT_LIST_HEAD(\u0026llcp_sock-\u003eaccept_queue);\n1030:\t\n1031:\t\tif (sock != NULL)\n1032:\t\t\tsock-\u003estate = SS_UNCONNECTED;\n1033:\t\n1034:\t\treturn sk;\n1035:\t}\n1036:\t\n1037:\tvoid nfc_llcp_sock_free(struct nfc_llcp_sock *sock)\n1038:\t{\n1039:\t\tkfree(sock-\u003eservice_name);\n" }
27/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 16201 output: 28 thoughts: 1243 Thoughts: Analyzing the LLCP Connection Logic Okay, so I'm diving into this LLCP connection process. It's immediately clear that `sk->sk_state` is initialized to `LLCP_CLOSED` right from the allocation, which makes sense. Then, looking at the `llcp_sock_connect` function, I see that the code checks `sk->sk_state` against `LLCP_CLOSED` on every single `connect()` call, even the very first one! On that initial call, a bunch of `llcp_sock` members are, of course, NULL or zero. So the code's going to run: ```c if (sk->sk_state == LLCP_CLOSED) { /* Release resources retained by a previous failed connection. / if (llcp_sock->local) { if (llcp_sock->reserved_ssap < LLCP_SAP_MAX) nfc_llcp_put_ssap(llcp_sock->local, llcp_sock->ssap); nfc_llcp_local_put(llcp_sock->local); } if (llcp_sock->dev) nfc_put_device(llcp_sock->dev); kfree(llcp_sock->service_name); llcp_sock->local = NULL; llcp_sock->dev = NULL; llcp_sock->service_name = NULL; llcp_sock->service_name_len = 0; llcp_sock->reserved_ssap = LLCP_SAP_MAX; } ``` This block, then, always* gets executed, even before any NFC device is involved in the setup! And on subsequent calls, it frees any lingering resources from failed connections (including ones that might have gone through a non-blocking `connect()` and then gotten disconnected). Wait a minute, is this even reachable? Yep, definitely. `socket(PF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP)` followed by `connect()` directly hits this code path. And here's the kicker: this doesn't require any special privileges for stream or datagram sockets. Let me verify: In `llcp_sock_create`, stream/dgram sockets are created without any capability requirements, just `socket(PF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP)`. So, the `connect()` call, specifically when the address family is `AF_NFC` and either `service_name_len` or `dsap` is non-zero, is going to call that cleanup block. This code is reached before any device is obtained. This happens even if no NFC hardware is present! The block runs before `nfc_get_device()`. So, whether or not an NFC device exists, the code I pointed out always runs, and with a device present repeated `connect()` calls can trigger the resource cleanup. Hold on, I need to investigate the implications of `llcp_sock->reserved_ssap` a bit more. I see that `nfc_llcp_put_ssap` is called if it's less than `LLCP_SAP_MAX`, but it passes `llcp_sock->ssap` not `llcp_sock->reserved_ssap`. Let me go check `llcp_sock_bind` and other functions to understand how this is used.
28/2	2026/09/27 14:16	tool	grepper	0m Args: { "Expression": "reserved_ssap", "PathPrefix": "net/nfc" } Results: { "Output": "net/nfc/llcp.h=102=struct nfc_llcp_sock {\n--\nnet/nfc/llcp.h-131-\t/* Reserved source SAP /\nnet/nfc/llcp.h:132:\tu8 reserved_ssap;\nnet/nfc/llcp.h-133-\n--\nnet/nfc/llcp_core.c=911=static void nfc_llcp_recv_connect(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-1003-\nnet/nfc/llcp_core.c:1004:\t\tpr_debug(\"reserved_ssap %d for %p\\n\", sock-\u003essap, new_sock);\nnet/nfc/llcp_core.c-1005-\n--\nnet/nfc/llcp_core.c-1009-\t\tatomic_inc(client_count);\nnet/nfc/llcp_core.c:1010:\t\tnew_sock-\u003ereserved_ssap = sock-\u003essap;\nnet/nfc/llcp_core.c-1011-\t}\n--\nnet/nfc/llcp_core.c=1286=static void nfc_llcp_recv_snl(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-1377-\t\t\t\tllcp_sock-\u003essap = sap;\nnet/nfc/llcp_core.c:1378:\t\t\t\tllcp_sock-\u003ereserved_ssap = sap;\nnet/nfc/llcp_core.c-1379-\t\t\t} else {\n--\nnet/nfc/llcp_sock.c=59=static int llcp_sock_bind(struct socket sock, struct sockaddr_unsized addr, int alen)\n--\nnet/nfc/llcp_sock.c-119-\nnet/nfc/llcp_sock.c:120:\tllcp_sock-\u003ereserved_ssap = llcp_sock-\u003essap;\nnet/nfc/llcp_sock.c-121-\n--\nnet/nfc/llcp_sock.c=602=static int llcp_sock_release(struct socket sock)\n--\nnet/nfc/llcp_sock.c-648-\nnet/nfc/llcp_sock.c:649:\tif (llcp_sock-\u003ereserved_ssap \u003c LLCP_SAP_MAX)\nnet/nfc/llcp_sock.c-650-\t\tnfc_llcp_put_ssap(llcp_sock-\u003elocal, llcp_sock-\u003essap);\n--\nnet/nfc/llcp_sock.c=661=static int llcp_sock_connect(struct socket sock, struct sockaddr_unsized _addr,\n--\nnet/nfc/llcp_sock.c-695-\t\tif (llcp_sock-\u003elocal) {\nnet/nfc/llcp_sock.c:696:\t\t\tif (llcp_sock-\u003ereserved_ssap \u003c LLCP_SAP_MAX)\nnet/nfc/llcp_sock.c-697-\t\t\t\tnfc_llcp_put_ssap(llcp_sock-\u003elocal, llcp_sock-\u003essap);\n--\nnet/nfc/llcp_sock.c-706-\t\tllcp_sock-\u003eservice_name_len = 0;\nnet/nfc/llcp_sock.c:707:\t\tllcp_sock-\u003ereserved_ssap = LLCP_SAP_MAX;\nnet/nfc/llcp_sock.c-708-\t}\n--\nnet/nfc/llcp_sock.c-743-\nnet/nfc/llcp_sock.c:744:\tllcp_sock-\u003ereserved_ssap = llcp_sock-\u003essap;\nnet/nfc/llcp_sock.c-745-\n--\nnet/nfc/llcp_sock.c=1001=struct sock nfc_llcp_sock_alloc(struct socket sock, int type, gfp_t gfp, int kern)\n--\nnet/nfc/llcp_sock.c-1024-\tllcp_sock-\u003eremote_ready = 1;\nnet/nfc/llcp_sock.c:1025:\tllcp_sock-\u003ereserved_ssap = LLCP_SAP_MAX;\nnet/nfc/llcp_sock.c-1026-\tnfc_llcp_socket_remote_param_init(llcp_sock);\n" }
29/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 19380 output: 38 thoughts: 391 Thoughts: LLCP Socket Resource Management - Potential Issue Okay, so I'm looking at how resources are managed within the LLCP socket layer. My initial focus was on `llcp_sock_release`. Yep, as expected, it releases the Service Access Point (SAP) if it was reserved. Specifically, it calls `nfc_llcp_put_ssap` if `llcp_sock->reserved_ssap` is within the valid range. Good. Makes sense. Now I'm diving into `llcp_sock_connect` and I'm seeing something slightly different. It also releases the SAP in the `LLCP_CLOSED` state, calling `nfc_llcp_put_ssap` in similar way. It appears to be doing some cleanup after a failed connection attempt. That's fine. It looks correct, so far. But wait a minute... What happens if the socket was bound first? The `bind()` operation would set `llcp_sock->local`, `reserved_ssap`, and all those relevant fields, correct? My concern is that `connect()` might try to release these resources even if they're still needed, potentially leading to double-freeing or data corruption. Okay, this requires deeper investigation! I'm going to check `llcp_sock_bind` to see how SAPs and local resources are managed during the binding process. I need to understand the interaction between `bind()` and `connect()` with respect to resource allocation and deallocation to be sure nothing gets improperly handled. I'll need to review the logic and ensure it's thread safe.
30/2	2026/09/27 14:16	tool	read-file	0m Args: { "File": "net/nfc/llcp_sock.c", "FirstLine": 55, "LineCount": 80 } Results: { "Contents": " 55:\t\t.owner = THIS_MODULE,\n 56:\t\t.obj_size = sizeof(struct nfc_llcp_sock),\n 57:\t};\n 58:\t\n 59:\tstatic int llcp_sock_bind(struct socket sock, struct sockaddr_unsized addr, int alen)\n 60:\t{\n 61:\t\tstruct sock sk = sock-\u003esk;\n 62:\t\tstruct nfc_llcp_sock llcp_sock = nfc_llcp_sock(sk);\n 63:\t\tstruct nfc_llcp_local local;\n 64:\t\tstruct nfc_dev dev;\n 65:\t\tstruct sockaddr_nfc_llcp llcp_addr;\n 66:\t\tint len, ret = 0;\n 67:\t\n 68:\t\tif (!addr \|\| alen \u003c offsetofend(struct sockaddr, sa_family) \|\|\n 69:\t\t addr-\u003esa_family != AF_NFC)\n 70:\t\t\treturn -EINVAL;\n 71:\t\n 72:\t\tpr_debug(\"sk %p addr %p family %d\\n\", sk, addr, addr-\u003esa_family);\n 73:\t\n 74:\t\tmemset(\u0026llcp_addr, 0, sizeof(llcp_addr));\n 75:\t\tlen = min_t(unsigned int, sizeof(llcp_addr), alen);\n 76:\t\tmemcpy(\u0026llcp_addr, addr, len);\n 77:\t\n 78:\t\t/* This is going to be a listening socket, dsap must be 0 */\n 79:\t\tif (llcp_addr.dsap != 0)\n 80:\t\t\treturn -EINVAL;\n 81:\t\n 82:\t\tlock_sock(sk);\n 83:\t\n 84:\t\tif (sk-\u003esk_state != LLCP_CLOSED) {\n 85:\t\t\tret = -EBADFD;\n 86:\t\t\tgoto error;\n 87:\t\t}\n 88:\t\n 89:\t\tdev = nfc_get_device(llcp_addr.dev_idx);\n 90:\t\tif (dev == NULL) {\n 91:\t\t\tret = -ENODEV;\n 92:\t\t\tgoto error;\n 93:\t\t}\n 94:\t\n 95:\t\tlocal = nfc_llcp_find_local(dev);\n 96:\t\tif (local == NULL) {\n 97:\t\t\tret = -ENODEV;\n 98:\t\t\tgoto put_dev;\n 99:\t\t}\n 100:\t\n 101:\t\tllcp_sock-\u003edev = dev;\n 102:\t\tllcp_sock-\u003elocal = local;\n 103:\t\tllcp_sock-\u003enfc_protocol = llcp_addr.nfc_protocol;\n 104:\t\tllcp_sock-\u003eservice_name_len = min_t(unsigned int,\n 105:\t\t\t\t\t\t llcp_addr.service_name_len,\n 106:\t\t\t\t\t\t NFC_LLCP_MAX_SERVICE_NAME);\n 107:\t\tllcp_sock-\u003eservice_name = kmemdup(llcp_addr.service_name,\n 108:\t\t\t\t\t\t llcp_sock-\u003eservice_name_len,\n 109:\t\t\t\t\t\t GFP_KERNEL);\n 110:\t\tif (!llcp_sock-\u003eservice_name) {\n 111:\t\t\tret = -ENOMEM;\n 112:\t\t\tgoto sock_llcp_put_local;\n 113:\t\t}\n 114:\t\tllcp_sock-\u003essap = nfc_llcp_get_sdp_ssap(local, llcp_sock);\n 115:\t\tif (llcp_sock-\u003essap == LLCP_SAP_MAX) {\n 116:\t\t\tret = -EADDRINUSE;\n 117:\t\t\tgoto free_service_name;\n 118:\t\t}\n 119:\t\n 120:\t\tllcp_sock-\u003ereserved_ssap = llcp_sock-\u003essap;\n 121:\t\n 122:\t\tnfc_llcp_sock_link(\u0026local-\u003esockets, sk);\n 123:\t\n 124:\t\tpr_debug(\"Socket bound to SAP %d\\n\", llcp_sock-\u003essap);\n 125:\t\n 126:\t\tsk-\u003esk_state = LLCP_BOUND;\n 127:\t\tnfc_put_device(dev);\n 128:\t\trelease_sock(sk);\n 129:\t\n 130:\t\treturn 0;\n 131:\t\n 132:\tfree_service_name:\n 133:\t\tkfree(llcp_sock-\u003eservice_name);\n 134:\t\tllcp_sock-\u003eservice_name = NULL;\n" }
31/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 21375 output: 28 thoughts: 175 Thoughts: Okay, let me break this down. Analyzing the LLCP Socket Connection Logic Alright, so the code says that if a socket is already bound, its `sk->sk_state` is set to `LLCP_BOUND`. That makes sense. Therefore, if `sk->sk_state` is not `LLCP_CLOSED`, which it wouldn't be if it's bound, the specific block of code inside `llcp_sock_connect` shouldn't execute. But hang on a second... what happens if we do attempt a connect on a socket that's already bound? I need to trace this more carefully. Specifically, within `llcp_sock_connect`, I see that `llcp_sock->dev = dev;` and `llcp_sock->local = local;` are being set. So even if it doesn't execute that block it may need to be handled further down the line. That's a potential area for a race condition or some unexpected behavior I need to consider. And more importantly, if a connection fails after it was attempted, where does the state go? What happens? I need to understand that transition. The crucial question is where `sk->sk_state` is ultimately set to `LLCP_CLOSED`, or what the failure path looks like. I'll need to search the `net/nfc` directory to find all the places where `LLCP_CLOSED` is used, and examine the surrounding code to determine how that state is reached. That will give me a clear picture of how failures are handled.
32/2	2026/09/27 14:16	tool	grepper	0m Args: { "Expression": "LLCP_CLOSED", "PathPrefix": "net/nfc" } Results: { "Output": "net/nfc/llcp.h=6=enum llcp_state {\n--\nnet/nfc/llcp.h-8-\tLLCP_CONNECTING,\nnet/nfc/llcp.h:9:\tLLCP_CLOSED,\nnet/nfc/llcp.h-10-\tLLCP_BOUND,\n--\nnet/nfc/llcp_core.c=66=static void nfc_llcp_socket_release(struct nfc_llcp_local local, bool device,\n--\nnet/nfc/llcp_core.c-100-\t\t\t\t\taccept_sk-\u003esk_err = err;\nnet/nfc/llcp_core.c:101:\t\t\t\taccept_sk-\u003esk_state = LLCP_CLOSED;\nnet/nfc/llcp_core.c-102-\t\t\t\taccept_sk-\u003esk_state_change(sk);\n--\nnet/nfc/llcp_core.c-109-\t\t\tsk-\u003esk_err = err;\nnet/nfc/llcp_core.c:110:\t\tsk-\u003esk_state = LLCP_CLOSED;\nnet/nfc/llcp_core.c-111-\t\tsk-\u003esk_state_change(sk);\n--\nnet/nfc/llcp_core.c-134-\t\t\tsk-\u003esk_err = err;\nnet/nfc/llcp_core.c:135:\t\tsk-\u003esk_state = LLCP_CLOSED;\nnet/nfc/llcp_core.c-136-\t\tsk-\u003esk_state_change(sk);\n--\nnet/nfc/llcp_core.c=1070=static void nfc_llcp_recv_hdlc(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-1092-\tlock_sock(sk);\nnet/nfc/llcp_core.c:1093:\tif (sk-\u003esk_state == LLCP_CLOSED) {\nnet/nfc/llcp_core.c-1094-\t\trelease_sock(sk);\n--\nnet/nfc/llcp_core.c=1158=static void nfc_llcp_recv_disc(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-1184-\nnet/nfc/llcp_core.c:1185:\tif (sk-\u003esk_state == LLCP_CLOSED) {\nnet/nfc/llcp_core.c-1186-\t\trelease_sock(sk);\n--\nnet/nfc/llcp_core.c-1192-\t\tnfc_put_device(local-\u003edev);\nnet/nfc/llcp_core.c:1193:\t\tsk-\u003esk_state = LLCP_CLOSED;\nnet/nfc/llcp_core.c-1194-\t\tsk-\u003esk_state_change(sk);\n--\nnet/nfc/llcp_core.c=1248=static void nfc_llcp_recv_dm(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-1279-\tsk-\u003esk_err = ENXIO;\nnet/nfc/llcp_core.c:1280:\tsk-\u003esk_state = LLCP_CLOSED;\nnet/nfc/llcp_core.c-1281-\tsk-\u003esk_state_change(sk);\n--\nnet/nfc/llcp_sock.c=59=static int llcp_sock_bind(struct socket sock, struct sockaddr_unsized addr, int alen)\n--\nnet/nfc/llcp_sock.c-83-\nnet/nfc/llcp_sock.c:84:\tif (sk-\u003esk_state != LLCP_CLOSED) {\nnet/nfc/llcp_sock.c-85-\t\tret = -EBADFD;\n--\nnet/nfc/llcp_sock.c=149=static int llcp_raw_sock_bind(struct socket sock, struct sockaddr_unsized addr,\n--\nnet/nfc/llcp_sock.c-170-\nnet/nfc/llcp_sock.c:171:\tif (sk-\u003esk_state != LLCP_CLOSED) {\nnet/nfc/llcp_sock.c-172-\t\tret = -EBADFD;\n--\nnet/nfc/llcp_sock.c=416=struct sock nfc_llcp_accept_dequeue(struct sock parent,\n--\nnet/nfc/llcp_sock.c-428-\nnet/nfc/llcp_sock.c:429:\t\tif (sk-\u003esk_state == LLCP_CLOSED) {\nnet/nfc/llcp_sock.c-430-\t\t\trelease_sock(sk);\n--\nnet/nfc/llcp_sock.c=563=static __poll_t llcp_sock_poll(struct file file, struct socket sock,\n--\nnet/nfc/llcp_sock.c-582-\nnet/nfc/llcp_sock.c:583:\tif (sk-\u003esk_state == LLCP_CLOSED)\nnet/nfc/llcp_sock.c-584-\t\tmask \|= EPOLLHUP;\n--\nnet/nfc/llcp_sock.c=661=static int llcp_sock_connect(struct socket sock, struct sockaddr_unsized _addr,\n--\nnet/nfc/llcp_sock.c-692-\nnet/nfc/llcp_sock.c:693:\tif (sk-\u003esk_state == LLCP_CLOSED) {\nnet/nfc/llcp_sock.c-694-\t\t/* Release resources retained by a previous failed connection. /\n--\nnet/nfc/llcp_sock.c=855=static int llcp_sock_recvmsg(struct socket sock, struct msghdr msg,\n--\nnet/nfc/llcp_sock.c-866-\nnet/nfc/llcp_sock.c:867:\tif (sk-\u003esk_state == LLCP_CLOSED \u0026\u0026\nnet/nfc/llcp_sock.c-868-\t skb_queue_empty(\u0026sk-\u003esk_receive_queue)) {\n--\nnet/nfc/llcp_sock.c=1001=struct sock nfc_llcp_sock_alloc(struct socket *sock, int type, gfp_t gfp, int kern)\n--\nnet/nfc/llcp_sock.c-1012-\tsock_init_data(sock, sk);\nnet/nfc/llcp_sock.c:1013:\tsk-\u003esk_state = LLCP_CLOSED;\nnet/nfc/llcp_sock.c-1014-\tsk-\u003esk_protocol = NFC_SOCKPROTO_LLCP;\n" }
33/2	2026/09/27 14:16	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 23646 output: 27 thoughts: 970 Thoughts: Analyzing the Reachability of an NFC LLCP Patch for Fuzzing Okay, here's the deal. This patch is targeting a memory management issue in the LLCP code, specifically within the NFC subsystem. My initial thought is that it's focusing on `sk->sk_state` being set to `LLCP_CLOSED` in multiple places – upon receiving certain messages (`nfc_llcp_recv_dm`, `nfc_llcp_recv_disc`), during socket release (`nfc_llcp_socket_release`), and, crucially, during initial allocation. The core issue is that when a connection fails or is intentionally disconnected, the code wasn't properly cleaning up the resources associated with the previous connection attempts. This included things like local devices, service names, and reserved SSAPs. The patch aims to free these resources when `sk->sk_state` is `LLCP_CLOSED`, preventing leaks. Now, the important question for me is: Is this code reachable and therefore fuzzable? I have to go through the checklist. The first section emphasizes that reachability is paramount. If it's not reachable in a standard environment, it's a no-go for fuzzing. Claims of "no functional change" or refactoring need extra scrutiny. And, critically, new or modified assertions must be fuzzed. The second section provides negative criteria: This isn't non-kernel, nor non-executable. It's not vendor-specific hardware, PCIe switches, smartNICs, or GPU drivers. But the question is, does NFC require physical hardware, or can it be reached in QEMU? So, I dig in. Can a user-space process simply call `socket(AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP)` and then `connect()`? Bingo! YES! The creation of `AF_NFC` sockets and the subsequent `connect()` call do NOT require any physical NFC hardware. This is a crucial finding. This means it's worth following the path. I trace the path: `socket()` calls `nfc_sock_create()` which in turn calls `llcp_sock_create()`. Here, the socket is created, its operations are set, and, the crucial part, `sk->sk_state` is initialized to `LLCP_CLOSED`. Then, `connect()` eventually leads to `llcp_sock_connect()`, which checks the address and, critically, checks `sk->sk_state`. If it's `LLCP_CLOSED`, the patch's cleanup code, which I showed above, is executed. This makes this patch worth fuzzing. Furthermore, I have to determine if NFC devices can exist in QEMU. Virtual NFC devices via nfcsim (`CONFIG_NFC_SIM`) or USB NFC dongles (emulated via syzkaller USB raw / vhci / usb-fuzzer) or virtual netlink NFC devices (`nfcsim`) do exist! This means there are ways to emulate NFC in the testing environment, increasing the likelihood that this code path can be hit during fuzzing. My conclusion? This code is reachable, and it's definitely worth fuzzing to discover potential issues that this patch might introduce, or regressions that the patch itself could expose.
34/2	2026/09/27 14:17	tool	grepper	0m Args: { "Expression": "nfcsim", "PathPrefix": "drivers/nfc" } Results: { "Output": "drivers/nfc/Makefile=10=obj-$(CONFIG_NFC_MEI_PHY)\t+= mei_phy.o\ndrivers/nfc/Makefile:11:obj-$(CONFIG_NFC_SIM)\t\t+= nfcsim.o\ndrivers/nfc/Makefile-12-obj-$(CONFIG_NFC_PORT100)\t+= port100.o\n--\ndrivers/nfc/nfcsim.c-30-\ndrivers/nfc/nfcsim.c:31:struct nfcsim {\ndrivers/nfc/nfcsim.c-32-\tstruct nfc_digital_dev nfc_digital_dev;\n--\ndrivers/nfc/nfcsim.c-36-\ndrivers/nfc/nfcsim.c:37:\tstruct nfcsim_link link_in;\ndrivers/nfc/nfcsim.c:38:\tstruct nfcsim_link link_out;\ndrivers/nfc/nfcsim.c-39-\n--\ndrivers/nfc/nfcsim.c-51-\ndrivers/nfc/nfcsim.c:52:struct nfcsim_link {\ndrivers/nfc/nfcsim.c-53-\tstruct mutex lock;\n--\ndrivers/nfc/nfcsim.c-64-\ndrivers/nfc/nfcsim.c:65:static struct nfcsim_link nfcsim_link_new(void)\ndrivers/nfc/nfcsim.c-66-{\ndrivers/nfc/nfcsim.c:67:\tstruct nfcsim_link link;\ndrivers/nfc/nfcsim.c-68-\ndrivers/nfc/nfcsim.c:69:\tlink = kzalloc_obj(struct nfcsim_link);\ndrivers/nfc/nfcsim.c-70-\tif (!link)\n--\ndrivers/nfc/nfcsim.c-78-\ndrivers/nfc/nfcsim.c:79:static void nfcsim_link_free(struct nfcsim_link link)\ndrivers/nfc/nfcsim.c-80-{\n--\ndrivers/nfc/nfcsim.c-84-\ndrivers/nfc/nfcsim.c:85:static void nfcsim_link_recv_wake(struct nfcsim_link link)\ndrivers/nfc/nfcsim.c-86-{\n--\ndrivers/nfc/nfcsim.c-90-\ndrivers/nfc/nfcsim.c:91:static void nfcsim_link_set_skb(struct nfcsim_link link, struct sk_buff skb,\ndrivers/nfc/nfcsim.c-92-\t\t\t\tu8 rf_tech, u8 mode)\n--\ndrivers/nfc/nfcsim.c-103-\ndrivers/nfc/nfcsim.c:104:static void nfcsim_link_recv_cancel(struct nfcsim_link link)\ndrivers/nfc/nfcsim.c-105-{\n--\ndrivers/nfc/nfcsim.c-111-\ndrivers/nfc/nfcsim.c:112:\tnfcsim_link_recv_wake(link);\ndrivers/nfc/nfcsim.c-113-}\ndrivers/nfc/nfcsim.c-114-\ndrivers/nfc/nfcsim.c:115:static void nfcsim_link_shutdown(struct nfcsim_link link)\ndrivers/nfc/nfcsim.c-116-{\n--\ndrivers/nfc/nfcsim.c-123-\ndrivers/nfc/nfcsim.c:124:\tnfcsim_link_recv_wake(link);\ndrivers/nfc/nfcsim.c-125-}\ndrivers/nfc/nfcsim.c-126-\ndrivers/nfc/nfcsim.c:127:static struct sk_buff nfcsim_link_recv_skb(struct nfcsim_link link,\ndrivers/nfc/nfcsim.c-128-\t\t\t\t\t int timeout, u8 rf_tech, u8 mode)\n--\ndrivers/nfc/nfcsim.c-169-\ndrivers/nfc/nfcsim.c:170:static void nfcsim_send_wq(struct work_struct work)\ndrivers/nfc/nfcsim.c-171-{\ndrivers/nfc/nfcsim.c:172:\tstruct nfcsim dev = container_of(work, struct nfcsim, send_work.work);\ndrivers/nfc/nfcsim.c-173-\n--\ndrivers/nfc/nfcsim.c-176-\t is the link_in of the peer device. The exchanged skb has already been\ndrivers/nfc/nfcsim.c:177:\t * stored in the dev-\u003elink_out through nfcsim_link_set_skb().\ndrivers/nfc/nfcsim.c-178-\t /\ndrivers/nfc/nfcsim.c:179:\tnfcsim_link_recv_wake(dev-\u003elink_out);\ndrivers/nfc/nfcsim.c-180-}\ndrivers/nfc/nfcsim.c-181-\ndrivers/nfc/nfcsim.c:182:static void nfcsim_recv_wq(struct work_struct work)\ndrivers/nfc/nfcsim.c-183-{\ndrivers/nfc/nfcsim.c:184:\tstruct nfcsim dev = container_of(work, struct nfcsim, recv_work);\ndrivers/nfc/nfcsim.c-185-\tstruct sk_buff skb;\ndrivers/nfc/nfcsim.c-186-\ndrivers/nfc/nfcsim.c:187:\tskb = nfcsim_link_recv_skb(dev-\u003elink_in, dev-\u003erecv_timeout,\ndrivers/nfc/nfcsim.c-188-\t\t\t\t dev-\u003erf_tech, dev-\u003emode);\n--\ndrivers/nfc/nfcsim.c-200-\ndrivers/nfc/nfcsim.c:201:static int nfcsim_send(struct nfc_digital_dev ddev, struct sk_buff skb,\ndrivers/nfc/nfcsim.c-202-\t\t u16 timeout, nfc_digital_cmd_complete_t cb, void arg)\ndrivers/nfc/nfcsim.c-203-{\ndrivers/nfc/nfcsim.c:204:\tstruct nfcsim dev = nfc_digital_get_drvdata(ddev);\ndrivers/nfc/nfcsim.c-205-\tu8 delay;\n--\ndrivers/nfc/nfcsim.c-226-\tif (skb) {\ndrivers/nfc/nfcsim.c:227:\t\tnfcsim_link_set_skb(dev-\u003elink_out, skb, dev-\u003erf_tech,\ndrivers/nfc/nfcsim.c-228-\t\t\t\t dev-\u003emode);\n--\ndrivers/nfc/nfcsim.c-239-\ndrivers/nfc/nfcsim.c:240:static void nfcsim_abort_cmd(struct nfc_digital_dev ddev)\ndrivers/nfc/nfcsim.c-241-{\ndrivers/nfc/nfcsim.c:242:\tconst struct nfcsim dev = nfc_digital_get_drvdata(ddev);\ndrivers/nfc/nfcsim.c-243-\ndrivers/nfc/nfcsim.c:244:\tnfcsim_link_recv_cancel(dev-\u003elink_in);\ndrivers/nfc/nfcsim.c-245-}\ndrivers/nfc/nfcsim.c-246-\ndrivers/nfc/nfcsim.c:247:static int nfcsim_switch_rf(struct nfc_digital_dev ddev, bool on)\ndrivers/nfc/nfcsim.c-248-{\ndrivers/nfc/nfcsim.c:249:\tstruct nfcsim dev = nfc_digital_get_drvdata(ddev);\ndrivers/nfc/nfcsim.c-250-\n--\ndrivers/nfc/nfcsim.c-255-\ndrivers/nfc/nfcsim.c:256:static int nfcsim_in_configure_hw(struct nfc_digital_dev ddev,\ndrivers/nfc/nfcsim.c-257-\t\t\t\t\t int type, int param)\ndrivers/nfc/nfcsim.c-258-{\ndrivers/nfc/nfcsim.c:259:\tstruct nfcsim dev = nfc_digital_get_drvdata(ddev);\ndrivers/nfc/nfcsim.c-260-\n--\ndrivers/nfc/nfcsim.c-278-\ndrivers/nfc/nfcsim.c:279:static int nfcsim_in_send_cmd(struct nfc_digital_dev ddev,\ndrivers/nfc/nfcsim.c-280-\t\t\t struct sk_buff skb, u16 timeout,\n--\ndrivers/nfc/nfcsim.c-282-{\ndrivers/nfc/nfcsim.c:283:\treturn nfcsim_send(ddev, skb, timeout, cb, arg);\ndrivers/nfc/nfcsim.c-284-}\ndrivers/nfc/nfcsim.c-285-\ndrivers/nfc/nfcsim.c:286:static int nfcsim_tg_configure_hw(struct nfc_digital_dev ddev,\ndrivers/nfc/nfcsim.c-287-\t\t\t\t\t int type, int param)\ndrivers/nfc/nfcsim.c-288-{\ndrivers/nfc/nfcsim.c:289:\tstruct nfcsim dev = nfc_digital_get_drvdata(ddev);\ndrivers/nfc/nfcsim.c-290-\n--\ndrivers/nfc/nfcsim.c-308-\ndrivers/nfc/nfcsim.c:309:static int nfcsim_tg_send_cmd(struct nfc_digital_dev ddev,\ndrivers/nfc/nfcsim.c-310-\t\t\t struct sk_buff skb, u16 timeout,\n--\ndrivers/nfc/nfcsim.c-312-{\ndrivers/nfc/nfcsim.c:313:\treturn nfcsim_send(ddev, skb, timeout, cb, arg);\ndrivers/nfc/nfcsim.c-314-}\ndrivers/nfc/nfcsim.c-315-\ndrivers/nfc/nfcsim.c:316:static int nfcsim_tg_listen(struct nfc_digital_dev ddev, u16 timeout,\ndrivers/nfc/nfcsim.c-317-\t\t\t nfc_digital_cmd_complete_t cb, void arg)\ndrivers/nfc/nfcsim.c-318-{\ndrivers/nfc/nfcsim.c:319:\treturn nfcsim_send(ddev, NULL, timeout, cb, arg);\ndrivers/nfc/nfcsim.c-320-}\ndrivers/nfc/nfcsim.c-321-\ndrivers/nfc/nfcsim.c:322:static const struct nfc_digital_ops nfcsim_digital_ops = {\ndrivers/nfc/nfcsim.c:323:\t.in_configure_hw = nfcsim_in_configure_hw,\ndrivers/nfc/nfcsim.c:324:\t.in_send_cmd = nfcsim_in_send_cmd,\ndrivers/nfc/nfcsim.c-325-\ndrivers/nfc/nfcsim.c:326:\t.tg_listen = nfcsim_tg_listen,\ndrivers/nfc/nfcsim.c:327:\t.tg_configure_hw = nfcsim_tg_configure_hw,\ndrivers/nfc/nfcsim.c:328:\t.tg_send_cmd = nfcsim_tg_send_cmd,\ndrivers/nfc/nfcsim.c-329-\ndrivers/nfc/nfcsim.c:330:\t.abort_cmd = nfcsim_abort_cmd,\ndrivers/nfc/nfcsim.c:331:\t.switch_rf = nfcsim_switch_rf,\ndrivers/nfc/nfcsim.c-332-};\ndrivers/nfc/nfcsim.c-333-\ndrivers/nfc/nfcsim.c:334:static struct dentry nfcsim_debugfs_root;\ndrivers/nfc/nfcsim.c-335-\ndrivers/nfc/nfcsim.c:336:static void nfcsim_debugfs_init(void)\ndrivers/nfc/nfcsim.c-337-{\ndrivers/nfc/nfcsim.c:338:\tnfcsim_debugfs_root = debugfs_create_dir(\"nfcsim\", NULL);\ndrivers/nfc/nfcsim.c-339-}\ndrivers/nfc/nfcsim.c-340-\ndrivers/nfc/nfcsim.c:341:static void nfcsim_debugfs_remove(void)\ndrivers/nfc/nfcsim.c-342-{\ndrivers/nfc/nfcsim.c:343:\tdebugfs_remove_recursive(nfcsim_debugfs_root);\ndrivers/nfc/nfcsim.c-344-}\ndrivers/nfc/nfcsim.c-345-\ndrivers/nfc/nfcsim.c:346:static void nfcsim_debugfs_init_dev(struct nfcsim dev)\ndrivers/nfc/nfcsim.c-347-{\n--\ndrivers/nfc/nfcsim.c-352-\ndrivers/nfc/nfcsim.c:353:\tif (!nfcsim_debugfs_root) {\ndrivers/nfc/nfcsim.c:354:\t\tNFCSIM_ERR(dev, \"nfcsim debugfs not initialized\\n\");\ndrivers/nfc/nfcsim.c-355-\t\treturn;\n--\ndrivers/nfc/nfcsim.c-364-\ndrivers/nfc/nfcsim.c:365:\tdev_dir = debugfs_create_dir(devname, nfcsim_debugfs_root);\ndrivers/nfc/nfcsim.c-366-\n--\ndrivers/nfc/nfcsim.c-369-\ndrivers/nfc/nfcsim.c:370:static struct nfcsim nfcsim_device_new(struct nfcsim_link link_in,\ndrivers/nfc/nfcsim.c:371:\t\t\t\t\tstruct nfcsim_link link_out)\ndrivers/nfc/nfcsim.c-372-{\ndrivers/nfc/nfcsim.c:373:\tstruct nfcsim dev;\ndrivers/nfc/nfcsim.c-374-\tint rc;\ndrivers/nfc/nfcsim.c-375-\ndrivers/nfc/nfcsim.c:376:\tdev = kzalloc_obj(struct nfcsim);\ndrivers/nfc/nfcsim.c-377-\tif (!dev)\n--\ndrivers/nfc/nfcsim.c-379-\ndrivers/nfc/nfcsim.c:380:\tINIT_DELAYED_WORK(\u0026dev-\u003esend_work, nfcsim_send_wq);\ndrivers/nfc/nfcsim.c:381:\tINIT_WORK(\u0026dev-\u003erecv_work, nfcsim_recv_wq);\ndrivers/nfc/nfcsim.c-382-\ndrivers/nfc/nfcsim.c-383-\tdev-\u003enfc_digital_dev =\ndrivers/nfc/nfcsim.c:384:\t\t\tnfc_digital_allocate_device(\u0026nfcsim_digital_ops,\ndrivers/nfc/nfcsim.c-385-\t\t\t\t\t\t NFC_PROTO_NFC_DEP_MASK,\n--\ndrivers/nfc/nfcsim.c-406-\ndrivers/nfc/nfcsim.c:407:\tnfcsim_debugfs_init_dev(dev);\ndrivers/nfc/nfcsim.c-408-\n--\ndrivers/nfc/nfcsim.c-411-\ndrivers/nfc/nfcsim.c:412:static void nfcsim_device_free(struct nfcsim dev)\ndrivers/nfc/nfcsim.c-413-{\n--\ndrivers/nfc/nfcsim.c-417-\ndrivers/nfc/nfcsim.c:418:\tnfcsim_link_shutdown(dev-\u003elink_in);\ndrivers/nfc/nfcsim.c-419-\n--\ndrivers/nfc/nfcsim.c-427-\ndrivers/nfc/nfcsim.c:428:static struct nfcsim dev0;\ndrivers/nfc/nfcsim.c:429:static struct nfcsim dev1;\ndrivers/nfc/nfcsim.c-430-\ndrivers/nfc/nfcsim.c:431:static int __init nfcsim_init(void)\ndrivers/nfc/nfcsim.c-432-{\ndrivers/nfc/nfcsim.c:433:\tstruct nfcsim_link link0, link1;\ndrivers/nfc/nfcsim.c-434-\tint rc;\ndrivers/nfc/nfcsim.c-435-\ndrivers/nfc/nfcsim.c:436:\tlink0 = nfcsim_link_new();\ndrivers/nfc/nfcsim.c:437:\tlink1 = nfcsim_link_new();\ndrivers/nfc/nfcsim.c-438-\tif (!link0 \|\| !link1) {\n--\ndrivers/nfc/nfcsim.c-442-\ndrivers/nfc/nfcsim.c:443:\tnfcsim_debugfs_init();\ndrivers/nfc/nfcsim.c-444-\ndrivers/nfc/nfcsim.c:445:\tdev0 = nfcsim_device_new(link0, link1);\ndrivers/nfc/nfcsim.c-446-\tif (IS_ERR(dev0)) {\n--\ndrivers/nfc/nfcsim.c-450-\ndrivers/nfc/nfcsim.c:451:\tdev1 = nfcsim_device_new(link1, link0);\ndrivers/nfc/nfcsim.c-452-\tif (IS_ERR(dev1)) {\ndrivers/nfc/nfcsim.c:453:\t\tnfcsim_device_free(dev0);\ndrivers/nfc/nfcsim.c-454-\n--\ndrivers/nfc/nfcsim.c-458-\ndrivers/nfc/nfcsim.c:459:\tpr_info(\"nfcsim \" NFCSIM_VERSION \" initialized\\n\");\ndrivers/nfc/nfcsim.c-460-\n--\ndrivers/nfc/nfcsim.c-463-exit_err:\ndrivers/nfc/nfcsim.c:464:\tpr_err(\"Failed to initialize nfcsim driver (%d)\\n\", rc);\ndrivers/nfc/nfcsim.c-465-\ndrivers/nfc/nfcsim.c-466-\tif (link0)\ndrivers/nfc/nfcsim.c:467:\t\tnfcsim_link_free(link0);\ndrivers/nfc/nfcsim.c-468-\tif (link1)\ndrivers/nfc/nfcsim.c:469:\t\tnfcsim_link_free(link1);\ndrivers/nfc/nfcsim.c-470-\n--\ndrivers/nfc/nfcsim.c-473-\ndrivers/nfc/nfcsim.c:474:static void __exit nfcsim_exit(void)\ndrivers/nfc/nfcsim.c-475-{\ndrivers/nfc/nfcsim.c:476:\tstruct nfcsim_link link0, *link1;\ndrivers/nfc/nfcsim.c-477-\n--\ndrivers/nfc/nfcsim.c-480-\ndrivers/nfc/nfcsim.c:481:\tnfcsim_device_free(dev0);\ndrivers/nfc/nfcsim.c:482:\tnfcsim_device_free(dev1);\ndrivers/nfc/nfcsim.c-483-\ndrivers/nfc/nfcsim.c:484:\tnfcsim_link_free(link0);\ndrivers/nfc/nfcsim.c:485:\tnfcsim_link_free(link1);\ndrivers/nfc/nfcsim.c-486-\ndrivers/nfc/nfcsim.c:487:\tnfcsim_debugfs_remove();\ndrivers/nfc/nfcsim.c-488-}\ndrivers/nfc/nfcsim.c-489-\ndrivers/nfc/nfcsim.c:490:module_init(nfcsim_init);\ndrivers/nfc/nfcsim.c:491:module_exit(nfcsim_exit);\ndrivers/nfc/nfcsim.c-492-\n" }
35/2	2026/09/27 14:17	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 30828 output: 26 thoughts: 555 Thoughts: My Analysis of the `llcp_sock_connect` Patch Okay, so here's what I've got. It seems like this `nfcsim` module, when `CONFIG_NFC_SIM` is enabled, automatically creates these loopback devices, `dev0` and `dev1`, on module load. That's good to know. And we can also emulate USB NFC devices using syzkaller's USB fuzzing, specifically targeting things like the PN533 USB driver via various `CONFIG_` options. That covers the hardware side of things. But what really caught my eye is that even without any physical or emulated NFC device, the `llcp_sock_connect` function gets executed immediately when a `connect` is invoked on an `AF_NFC` socket. Let's dig into that. First, I created a test scenario: `socket(AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP)`. No device required, and the socket creation works perfectly fine. Then, I invoked `connect()`. I checked the code, and here's the breakdown: Lines 673-677 validate the address format. Lines 684-691 check for an existing connection or connection attempt. Then, lines 693-708: Bingo! That's the new code we are interested in! Finally, at line 710+, the code attempts to lookup the device (`dev = nfc_get_device(...)`) and if the device is null, it just returns `-ENODEV`. So, this new code runs every time `connect()` is called on an `AF_NFC` LLCP socket, regardless of device presence. That's a huge potential attack surface! Now, the crucial question: Is this fuzzable? I consulted Section 3 regarding "WorthFuzzing" criteria. It explicitly states that "Reachable Drivers and Protocols" are worth fuzzing, and it names sockets as a relevant access method. Since AF_NFC socket operations are fully accessible through the sockets API, and this patch modifies `llcp_sock_connect`, which cleans up resources when `sk->sk_state == LLCP_CLOSED`, this code is definitely reachable and executable from user space via the standard `socket(AF_NFC, ...)` and `connect()` calls. Excellent! Finally, I checked `net/nfc/Makefile` and `net/nfc/Kconfig` to determine what configs are needed. `llcp_sock.c` is part of `nfc-objs`, which is included when `CONFIG_NFC` is enabled. I also searched for "LLCP" in `Kconfig` to see if there are any specific configs for LLCP, but I haven't found any other relevant configurations. So, it seems enabling `CONFIG_NFC` is all that's needed to trigger the code. This looks like a ripe target for fuzzing. The code is new, reachable, and accessible via a straightforward API.
36/2	2026/09/27 14:17	tool	grepper	0m Args: { "Expression": "LLCP", "PathPrefix": "net/nfc" } Results: { "Output": "\nFull output is too long, showing 500 out of 985 lines.\nUse more precise expression if possible.\n\nnet/nfc/core.c=655=int nfc_tm_data_received(struct nfc_dev dev, struct sk_buff skb)\nnet/nfc/core.c-656-{\nnet/nfc/core.c:657:\t/* Only LLCP target mode for now /\nnet/nfc/core.c-658-\tif (dev-\u003edep_link_up == false) {\n--\nnet/nfc/llcp.h=6=enum llcp_state {\nnet/nfc/llcp.h:7:\tLLCP_CONNECTED = 1, / wait_for_packet() wants that /\nnet/nfc/llcp.h:8:\tLLCP_CONNECTING,\nnet/nfc/llcp.h:9:\tLLCP_CLOSED,\nnet/nfc/llcp.h:10:\tLLCP_BOUND,\nnet/nfc/llcp.h:11:\tLLCP_LISTEN,\nnet/nfc/llcp.h-12-};\nnet/nfc/llcp.h-13-\nnet/nfc/llcp.h:14:#define LLCP_DEFAULT_LTO 100\nnet/nfc/llcp.h:15:#define LLCP_DEFAULT_RW 1\nnet/nfc/llcp.h:16:#define LLCP_DEFAULT_MIU 128\nnet/nfc/llcp.h-17-\nnet/nfc/llcp.h:18:#define LLCP_MAX_LTO 0xff\nnet/nfc/llcp.h:19:#define LLCP_MAX_RW 15\nnet/nfc/llcp.h:20:#define LLCP_MAX_MIUX 0x7ff\nnet/nfc/llcp.h:21:#define LLCP_MAX_MIU (LLCP_MAX_MIUX + 128)\nnet/nfc/llcp.h-22-\nnet/nfc/llcp.h:23:#define LLCP_WKS_NUM_SAP 16\nnet/nfc/llcp.h:24:#define LLCP_SDP_NUM_SAP 16\nnet/nfc/llcp.h:25:#define LLCP_LOCAL_NUM_SAP 32\nnet/nfc/llcp.h:26:#define LLCP_LOCAL_SAP_OFFSET (LLCP_WKS_NUM_SAP + LLCP_SDP_NUM_SAP)\nnet/nfc/llcp.h:27:#define LLCP_MAX_SAP (LLCP_WKS_NUM_SAP + LLCP_SDP_NUM_SAP + LLCP_LOCAL_NUM_SAP)\nnet/nfc/llcp.h:28:#define LLCP_SDP_UNBOUND (LLCP_MAX_SAP + 1)\nnet/nfc/llcp.h-29-\n--\nnet/nfc/llcp.h=50=struct nfc_llcp_local {\n--\nnet/nfc/llcp.h-73-\tunsigned long local_sap; / Local SAPs, not available for discovery /\nnet/nfc/llcp.h:74:\tatomic_t local_sdp_cnt[LLCP_SDP_NUM_SAP];\nnet/nfc/llcp.h-75-\n--\nnet/nfc/llcp.h=141=struct nfc_llcp_ui_cb {\n--\nnet/nfc/llcp.h-150-\nnet/nfc/llcp.h:151:#define LLCP_HEADER_SIZE 2\nnet/nfc/llcp.h:152:#define LLCP_SEQUENCE_SIZE 1\nnet/nfc/llcp.h:153:#define LLCP_AGF_PDU_HEADER_SIZE 2\nnet/nfc/llcp.h-154-\nnet/nfc/llcp.h:155:/ LLCP versions: 1.1 is 1.0 plus SDP /\nnet/nfc/llcp.h:156:#define LLCP_VERSION_10 0x10\nnet/nfc/llcp.h:157:#define LLCP_VERSION_11 0x11\nnet/nfc/llcp.h-158-\nnet/nfc/llcp.h:159:/ LLCP PDU types /\nnet/nfc/llcp.h:160:#define LLCP_PDU_SYMM 0x0\nnet/nfc/llcp.h:161:#define LLCP_PDU_PAX 0x1\nnet/nfc/llcp.h:162:#define LLCP_PDU_AGF 0x2\nnet/nfc/llcp.h:163:#define LLCP_PDU_UI 0x3\nnet/nfc/llcp.h:164:#define LLCP_PDU_CONNECT 0x4\nnet/nfc/llcp.h:165:#define LLCP_PDU_DISC 0x5\nnet/nfc/llcp.h:166:#define LLCP_PDU_CC 0x6\nnet/nfc/llcp.h:167:#define LLCP_PDU_DM 0x7\nnet/nfc/llcp.h:168:#define LLCP_PDU_FRMR 0x8\nnet/nfc/llcp.h:169:#define LLCP_PDU_SNL 0x9\nnet/nfc/llcp.h:170:#define LLCP_PDU_I 0xc\nnet/nfc/llcp.h:171:#define LLCP_PDU_RR 0xd\nnet/nfc/llcp.h:172:#define LLCP_PDU_RNR 0xe\nnet/nfc/llcp.h-173-\nnet/nfc/llcp.h-174-/ Parameters TLV types /\nnet/nfc/llcp.h:175:#define LLCP_TLV_VERSION 0x1\nnet/nfc/llcp.h:176:#define LLCP_TLV_MIUX 0x2\nnet/nfc/llcp.h:177:#define LLCP_TLV_WKS 0x3\nnet/nfc/llcp.h:178:#define LLCP_TLV_LTO 0x4\nnet/nfc/llcp.h:179:#define LLCP_TLV_RW 0x5\nnet/nfc/llcp.h:180:#define LLCP_TLV_SN 0x6\nnet/nfc/llcp.h:181:#define LLCP_TLV_OPT 0x7\nnet/nfc/llcp.h:182:#define LLCP_TLV_SDREQ 0x8\nnet/nfc/llcp.h:183:#define LLCP_TLV_SDRES 0x9\nnet/nfc/llcp.h:184:#define LLCP_TLV_MAX 0xa\nnet/nfc/llcp.h-185-\nnet/nfc/llcp.h:186:/ Well known LLCP SAP /\nnet/nfc/llcp.h:187:#define LLCP_SAP_SDP 0x1\nnet/nfc/llcp.h:188:#define LLCP_SAP_IP 0x2\nnet/nfc/llcp.h:189:#define LLCP_SAP_OBEX 0x3\nnet/nfc/llcp.h:190:#define LLCP_SAP_SNEP 0x4\nnet/nfc/llcp.h:191:#define LLCP_SAP_MAX 0xff\nnet/nfc/llcp.h-192-\nnet/nfc/llcp.h-193-/ Disconnection reason code /\nnet/nfc/llcp.h:194:#define LLCP_DM_DISC 0x00\nnet/nfc/llcp.h:195:#define LLCP_DM_NOCONN 0x01\nnet/nfc/llcp.h:196:#define LLCP_DM_NOBOUND 0x02\nnet/nfc/llcp.h:197:#define LLCP_DM_REJ 0x03\nnet/nfc/llcp.h-198-\n--\nnet/nfc/llcp_commands.c-17-\nnet/nfc/llcp_commands.c:18:static const u8 llcp_tlv_length[LLCP_TLV_MAX] = {\nnet/nfc/llcp_commands.c-19-\t0,\n--\nnet/nfc/llcp_commands.c=49=static u8 llcp_tlv_version(const u8 tlv)\nnet/nfc/llcp_commands.c-50-{\nnet/nfc/llcp_commands.c:51:\treturn llcp_tlv8(tlv, LLCP_TLV_VERSION);\nnet/nfc/llcp_commands.c-52-}\n--\nnet/nfc/llcp_commands.c=54=static u16 llcp_tlv_miux(const u8 tlv)\nnet/nfc/llcp_commands.c-55-{\nnet/nfc/llcp_commands.c:56:\treturn llcp_tlv16(tlv, LLCP_TLV_MIUX) \u0026 0x7ff;\nnet/nfc/llcp_commands.c-57-}\n--\nnet/nfc/llcp_commands.c=59=static u16 llcp_tlv_wks(const u8 tlv)\nnet/nfc/llcp_commands.c-60-{\nnet/nfc/llcp_commands.c:61:\treturn llcp_tlv16(tlv, LLCP_TLV_WKS);\nnet/nfc/llcp_commands.c-62-}\n--\nnet/nfc/llcp_commands.c=64=static u16 llcp_tlv_lto(const u8 tlv)\nnet/nfc/llcp_commands.c-65-{\nnet/nfc/llcp_commands.c:66:\treturn llcp_tlv8(tlv, LLCP_TLV_LTO);\nnet/nfc/llcp_commands.c-67-}\n--\nnet/nfc/llcp_commands.c=69=static u8 llcp_tlv_opt(const u8 tlv)\nnet/nfc/llcp_commands.c-70-{\nnet/nfc/llcp_commands.c:71:\treturn llcp_tlv8(tlv, LLCP_TLV_OPT);\nnet/nfc/llcp_commands.c-72-}\n--\nnet/nfc/llcp_commands.c=74=static u8 llcp_tlv_rw(const u8 tlv)\nnet/nfc/llcp_commands.c-75-{\nnet/nfc/llcp_commands.c:76:\treturn llcp_tlv8(tlv, LLCP_TLV_RW) \u0026 0xf;\nnet/nfc/llcp_commands.c-77-}\n--\nnet/nfc/llcp_commands.c=79=u8 nfc_llcp_build_tlv(u8 type, const u8 value, u8 value_length, u8 tlv_length)\n--\nnet/nfc/llcp_commands.c-84-\nnet/nfc/llcp_commands.c:85:\tif (type \u003e= LLCP_TLV_MAX)\nnet/nfc/llcp_commands.c-86-\t\treturn NULL;\n--\nnet/nfc/llcp_commands.c=106=struct nfc_llcp_sdp_tlv nfc_llcp_build_sdres_tlv(u8 tid, u8 sap)\n--\nnet/nfc/llcp_commands.c-117-\nnet/nfc/llcp_commands.c:118:\tsdres-\u003etlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2,\nnet/nfc/llcp_commands.c-119-\t\t\t\t\t\u0026sdres-\u003etlv_len);\n--\nnet/nfc/llcp_commands.c=133=struct nfc_llcp_sdp_tlv nfc_llcp_build_sdreq_tlv(u8 tid, const char uri,\n--\nnet/nfc/llcp_commands.c-158-\nnet/nfc/llcp_commands.c:159:\tsdreq-\u003etlv[0] = LLCP_TLV_SDREQ;\nnet/nfc/llcp_commands.c-160-\tsdreq-\u003etlv[1] = sdreq-\u003etlv_len - 2;\n--\nnet/nfc/llcp_commands.c=192=int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_commands.c-216-\t\tswitch (type) {\nnet/nfc/llcp_commands.c:217:\t\tcase LLCP_TLV_VERSION:\nnet/nfc/llcp_commands.c-218-\t\t\tlocal-\u003eremote_version = llcp_tlv_version(tlv);\nnet/nfc/llcp_commands.c-219-\t\t\tbreak;\nnet/nfc/llcp_commands.c:220:\t\tcase LLCP_TLV_MIUX:\nnet/nfc/llcp_commands.c-221-\t\t\tlocal-\u003eremote_miu = llcp_tlv_miux(tlv) + 128;\nnet/nfc/llcp_commands.c-222-\t\t\tbreak;\nnet/nfc/llcp_commands.c:223:\t\tcase LLCP_TLV_WKS:\nnet/nfc/llcp_commands.c-224-\t\t\tlocal-\u003eremote_wks = llcp_tlv_wks(tlv);\nnet/nfc/llcp_commands.c-225-\t\t\tbreak;\nnet/nfc/llcp_commands.c:226:\t\tcase LLCP_TLV_LTO:\nnet/nfc/llcp_commands.c-227-\t\t\tlocal-\u003eremote_lto = llcp_tlv_lto(tlv) * 10;\nnet/nfc/llcp_commands.c-228-\t\t\tbreak;\nnet/nfc/llcp_commands.c:229:\t\tcase LLCP_TLV_OPT:\nnet/nfc/llcp_commands.c-230-\t\t\tlocal-\u003eremote_opt = llcp_tlv_opt(tlv);\n--\nnet/nfc/llcp_commands.c=249=int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock sock,\n--\nnet/nfc/llcp_commands.c-273-\t\tswitch (type) {\nnet/nfc/llcp_commands.c:274:\t\tcase LLCP_TLV_MIUX:\nnet/nfc/llcp_commands.c-275-\t\t\tsock-\u003eremote_miu = llcp_tlv_miux(tlv) + 128;\nnet/nfc/llcp_commands.c-276-\t\t\tbreak;\nnet/nfc/llcp_commands.c:277:\t\tcase LLCP_TLV_RW:\nnet/nfc/llcp_commands.c-278-\t\t\tsock-\u003eremote_rw = llcp_tlv_rw(tlv);\nnet/nfc/llcp_commands.c-279-\t\t\tbreak;\nnet/nfc/llcp_commands.c:280:\t\tcase LLCP_TLV_SN:\nnet/nfc/llcp_commands.c-281-\t\t\tbreak;\n--\nnet/nfc/llcp_commands.c=297=static struct sk_buff llcp_add_header(struct sk_buff pdu,\n--\nnet/nfc/llcp_commands.c-308-\nnet/nfc/llcp_commands.c:309:\tskb_put_data(pdu, header, LLCP_HEADER_SIZE);\nnet/nfc/llcp_commands.c-310-\n--\nnet/nfc/llcp_commands.c=327=static struct sk_buff llcp_allocate_pdu(struct nfc_llcp_sock sock,\n--\nnet/nfc/llcp_commands.c-336-\tskb = nfc_alloc_send_skb(sock-\u003edev, \u0026sock-\u003esk, MSG_DONTWAIT,\nnet/nfc/llcp_commands.c:337:\t\t\t\t size + LLCP_HEADER_SIZE, \u0026err);\nnet/nfc/llcp_commands.c-338-\tif (skb == NULL) {\n--\nnet/nfc/llcp_commands.c=348=int nfc_llcp_send_disconnect(struct nfc_llcp_sock sock)\n--\nnet/nfc/llcp_commands.c-361-\nnet/nfc/llcp_commands.c:362:\tskb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);\nnet/nfc/llcp_commands.c-363-\tif (skb == NULL)\n--\nnet/nfc/llcp_commands.c=371=int nfc_llcp_send_symm(struct nfc_dev dev)\n--\nnet/nfc/llcp_commands.c-381-\nnet/nfc/llcp_commands.c:382:\tsize += LLCP_HEADER_SIZE;\nnet/nfc/llcp_commands.c-383-\tsize += dev-\u003etx_headroom + dev-\u003etx_tailroom + NFC_HEADER_SIZE;\n--\nnet/nfc/llcp_commands.c-392-\nnet/nfc/llcp_commands.c:393:\tskb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);\nnet/nfc/llcp_commands.c-394-\n--\nnet/nfc/llcp_commands.c=406=int nfc_llcp_send_connect(struct nfc_llcp_sock sock)\n--\nnet/nfc/llcp_commands.c-423-\tif (sock-\u003eservice_name != NULL) {\nnet/nfc/llcp_commands.c:424:\t\tservice_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,\nnet/nfc/llcp_commands.c-425-\t\t\t\t\t\t sock-\u003eservice_name,\n--\nnet/nfc/llcp_commands.c-435-\t/* If the socket parameters are not set, use the local ones /\nnet/nfc/llcp_commands.c:436:\tmiux = be16_to_cpu(sock-\u003emiux) \u003e LLCP_MAX_MIUX ?\nnet/nfc/llcp_commands.c-437-\t\tlocal-\u003emiux : sock-\u003emiux;\nnet/nfc/llcp_commands.c:438:\trw = sock-\u003erw \u003e LLCP_MAX_RW ? local-\u003erw : sock-\u003erw;\nnet/nfc/llcp_commands.c-439-\nnet/nfc/llcp_commands.c:440:\tmiux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 )\u0026miux, 0,\nnet/nfc/llcp_commands.c-441-\t\t\t\t \u0026miux_tlv_length);\n--\nnet/nfc/llcp_commands.c-447-\nnet/nfc/llcp_commands.c:448:\trw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, \u0026rw, 0, \u0026rw_tlv_length);\nnet/nfc/llcp_commands.c-449-\tif (!rw_tlv) {\n--\nnet/nfc/llcp_commands.c-456-\nnet/nfc/llcp_commands.c:457:\tskb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);\nnet/nfc/llcp_commands.c-458-\tif (skb == NULL) {\n--\nnet/nfc/llcp_commands.c=482=int nfc_llcp_send_cc(struct nfc_llcp_sock sock)\n--\nnet/nfc/llcp_commands.c-497-\t/ If the socket parameters are not set, use the local ones /\nnet/nfc/llcp_commands.c:498:\tmiux = be16_to_cpu(sock-\u003emiux) \u003e LLCP_MAX_MIUX ?\nnet/nfc/llcp_commands.c-499-\t\tlocal-\u003emiux : sock-\u003emiux;\nnet/nfc/llcp_commands.c:500:\trw = sock-\u003erw \u003e LLCP_MAX_RW ? local-\u003erw : sock-\u003erw;\nnet/nfc/llcp_commands.c-501-\nnet/nfc/llcp_commands.c:502:\tmiux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 )\u0026miux, 0,\nnet/nfc/llcp_commands.c-503-\t\t\t\t \u0026miux_tlv_length);\n--\nnet/nfc/llcp_commands.c-509-\nnet/nfc/llcp_commands.c:510:\trw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, \u0026rw, 0, \u0026rw_tlv_length);\nnet/nfc/llcp_commands.c-511-\tif (!rw_tlv) {\n--\nnet/nfc/llcp_commands.c-516-\nnet/nfc/llcp_commands.c:517:\tskb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);\nnet/nfc/llcp_commands.c-518-\tif (skb == NULL) {\n--\nnet/nfc/llcp_commands.c=540=static struct sk_buff nfc_llcp_allocate_snl(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_commands.c-553-\nnet/nfc/llcp_commands.c:554:\tsize += LLCP_HEADER_SIZE;\nnet/nfc/llcp_commands.c-555-\tsize += dev-\u003etx_headroom + dev-\u003etx_tailroom + NFC_HEADER_SIZE;\n--\nnet/nfc/llcp_commands.c-563-\nnet/nfc/llcp_commands.c:564:\tskb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);\nnet/nfc/llcp_commands.c-565-\n--\nnet/nfc/llcp_commands.c=627=int nfc_llcp_send_dm(struct nfc_llcp_local local, u8 ssap, u8 dsap, u8 reason)\n--\nnet/nfc/llcp_commands.c-641-\nnet/nfc/llcp_commands.c:642:\tsize += LLCP_HEADER_SIZE;\nnet/nfc/llcp_commands.c-643-\tsize += dev-\u003etx_headroom + dev-\u003etx_tailroom + NFC_HEADER_SIZE;\n--\nnet/nfc/llcp_commands.c-650-\nnet/nfc/llcp_commands.c:651:\tskb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);\nnet/nfc/llcp_commands.c-652-\n--\nnet/nfc/llcp_commands.c=660=int nfc_llcp_send_i_frame(struct nfc_llcp_sock sock,\n--\nnet/nfc/llcp_commands.c-705-\tdo {\nnet/nfc/llcp_commands.c:706:\t\tremote_miu = sock-\u003eremote_miu \u003e LLCP_MAX_MIU ?\nnet/nfc/llcp_commands.c:707:\t\t\t\tLLCP_DEFAULT_MIU : sock-\u003eremote_miu;\nnet/nfc/llcp_commands.c-708-\n--\nnet/nfc/llcp_commands.c-713-\nnet/nfc/llcp_commands.c:714:\t\tpdu = llcp_allocate_pdu(sock, LLCP_PDU_I,\nnet/nfc/llcp_commands.c:715:\t\t\t\t\tfrag_len + LLCP_SEQUENCE_SIZE);\nnet/nfc/llcp_commands.c-716-\t\tif (pdu == NULL) {\n--\nnet/nfc/llcp_commands.c-720-\nnet/nfc/llcp_commands.c:721:\t\tskb_put(pdu, LLCP_SEQUENCE_SIZE);\nnet/nfc/llcp_commands.c-722-\n--\nnet/nfc/llcp_commands.c=743=int nfc_llcp_send_ui_frame(struct nfc_llcp_sock sock, u8 ssap, u8 dsap,\n--\nnet/nfc/llcp_commands.c-771-\tdo {\nnet/nfc/llcp_commands.c:772:\t\tremote_miu = sock-\u003eremote_miu \u003e LLCP_MAX_MIU ?\nnet/nfc/llcp_commands.c-773-\t\t\t\tlocal-\u003eremote_miu : sock-\u003eremote_miu;\n--\nnet/nfc/llcp_commands.c-780-\t\tpdu = nfc_alloc_send_skb(sock-\u003edev, \u0026sock-\u003esk, 0,\nnet/nfc/llcp_commands.c:781:\t\t\t\t\t frag_len + LLCP_HEADER_SIZE, \u0026err);\nnet/nfc/llcp_commands.c-782-\t\tif (pdu == NULL) {\n--\nnet/nfc/llcp_commands.c-789-\nnet/nfc/llcp_commands.c:790:\t\tpdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);\nnet/nfc/llcp_commands.c-791-\n--\nnet/nfc/llcp_commands.c=822=int nfc_llcp_send_rr(struct nfc_llcp_sock sock)\n--\nnet/nfc/llcp_commands.c-832-\nnet/nfc/llcp_commands.c:833:\tskb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);\nnet/nfc/llcp_commands.c-834-\tif (skb == NULL)\n--\nnet/nfc/llcp_commands.c-836-\nnet/nfc/llcp_commands.c:837:\tskb_put(skb, LLCP_SEQUENCE_SIZE);\nnet/nfc/llcp_commands.c-838-\n--\nnet/nfc/llcp_core.c=39=void nfc_llcp_socket_remote_param_init(struct nfc_llcp_sock sock)\nnet/nfc/llcp_core.c-40-{\nnet/nfc/llcp_core.c:41:\tsock-\u003eremote_rw = LLCP_DEFAULT_RW;\nnet/nfc/llcp_core.c:42:\tsock-\u003eremote_miu = LLCP_MAX_MIU + 1;\nnet/nfc/llcp_core.c-43-}\n--\nnet/nfc/llcp_core.c=66=static void nfc_llcp_socket_release(struct nfc_llcp_local local, bool device,\n--\nnet/nfc/llcp_core.c-83-\nnet/nfc/llcp_core.c:84:\t\tif (sk-\u003esk_state == LLCP_CONNECTED)\nnet/nfc/llcp_core.c-85-\t\t\tnfc_put_device(llcp_sock-\u003edev);\nnet/nfc/llcp_core.c-86-\nnet/nfc/llcp_core.c:87:\t\tif (sk-\u003esk_state == LLCP_LISTEN) {\nnet/nfc/llcp_core.c-88-\t\t\tstruct nfc_llcp_sock lsk, n;\n--\nnet/nfc/llcp_core.c-100-\t\t\t\t\taccept_sk-\u003esk_err = err;\nnet/nfc/llcp_core.c:101:\t\t\t\taccept_sk-\u003esk_state = LLCP_CLOSED;\nnet/nfc/llcp_core.c-102-\t\t\t\taccept_sk-\u003esk_state_change(sk);\n--\nnet/nfc/llcp_core.c-109-\t\t\tsk-\u003esk_err = err;\nnet/nfc/llcp_core.c:110:\t\tsk-\u003esk_state = LLCP_CLOSED;\nnet/nfc/llcp_core.c-111-\t\tsk-\u003esk_state_change(sk);\n--\nnet/nfc/llcp_core.c-134-\t\t\tsk-\u003esk_err = err;\nnet/nfc/llcp_core.c:135:\t\tsk-\u003esk_state = LLCP_CLOSED;\nnet/nfc/llcp_core.c-136-\t\tsk-\u003esk_state_change(sk);\n--\nnet/nfc/llcp_core.c=254=static void nfc_llcp_sdreq_timeout_work(struct work_struct work)\n--\nnet/nfc/llcp_core.c-270-\nnet/nfc/llcp_core.c:271:\t\tsdp-\u003esap = LLCP_SDP_UNBOUND;\nnet/nfc/llcp_core.c-272-\n--\nnet/nfc/llcp_core.c=363=struct nfc_llcp_sock nfc_llcp_sock_from_sn(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-384-\t\tif (tmp_sock-\u003esk.sk_type == SOCK_STREAM \u0026\u0026\nnet/nfc/llcp_core.c:385:\t\t tmp_sock-\u003esk.sk_state != LLCP_LISTEN)\nnet/nfc/llcp_core.c-386-\t\t\tcontinue;\n--\nnet/nfc/llcp_core.c-388-\t\tif (tmp_sock-\u003esk.sk_type == SOCK_DGRAM \u0026\u0026\nnet/nfc/llcp_core.c:389:\t\t tmp_sock-\u003esk.sk_state != LLCP_BOUND)\nnet/nfc/llcp_core.c-390-\t\t\tcontinue;\n--\nnet/nfc/llcp_core.c=414=u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-429-\nnet/nfc/llcp_core.c:430:\t\t\t\treturn LLCP_SAP_MAX;\nnet/nfc/llcp_core.c-431-\t\t\t}\n--\nnet/nfc/llcp_core.c-447-\nnet/nfc/llcp_core.c:448:\t\t\treturn LLCP_SAP_MAX;\nnet/nfc/llcp_core.c-449-\t\t}\n--\nnet/nfc/llcp_core.c-452-\nnet/nfc/llcp_core.c:453:\t\treturn LLCP_SDP_UNBOUND;\nnet/nfc/llcp_core.c-454-\nnet/nfc/llcp_core.c:455:\t} else if (sock-\u003essap != 0 \u0026\u0026 sock-\u003essap \u003c LLCP_WKS_NUM_SAP) {\nnet/nfc/llcp_core.c-456-\t\tif (!test_bit(sock-\u003essap, \u0026local-\u003elocal_wks)) {\n--\nnet/nfc/llcp_core.c-465-\nnet/nfc/llcp_core.c:466:\treturn LLCP_SAP_MAX;\nnet/nfc/llcp_core.c-467-}\n--\nnet/nfc/llcp_core.c=469=u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local local)\n--\nnet/nfc/llcp_core.c-474-\nnet/nfc/llcp_core.c:475:\tlocal_ssap = find_first_zero_bit(\u0026local-\u003elocal_sap, LLCP_LOCAL_NUM_SAP);\nnet/nfc/llcp_core.c:476:\tif (local_ssap == LLCP_LOCAL_NUM_SAP) {\nnet/nfc/llcp_core.c-477-\t\tmutex_unlock(\u0026local-\u003esdp_lock);\nnet/nfc/llcp_core.c:478:\t\treturn LLCP_SAP_MAX;\nnet/nfc/llcp_core.c-479-\t}\n--\nnet/nfc/llcp_core.c-484-\nnet/nfc/llcp_core.c:485:\treturn local_ssap + LLCP_LOCAL_SAP_OFFSET;\nnet/nfc/llcp_core.c-486-}\n--\nnet/nfc/llcp_core.c=488=void nfc_llcp_put_ssap(struct nfc_llcp_local local, u8 ssap)\n--\nnet/nfc/llcp_core.c-492-\nnet/nfc/llcp_core.c:493:\tif (ssap \u003c LLCP_WKS_NUM_SAP) {\nnet/nfc/llcp_core.c-494-\t\tlocal_ssap = ssap;\nnet/nfc/llcp_core.c-495-\t\tsdp = \u0026local-\u003elocal_wks;\nnet/nfc/llcp_core.c:496:\t} else if (ssap \u003c LLCP_LOCAL_NUM_SAP) {\nnet/nfc/llcp_core.c-497-\t\tatomic_t client_cnt;\nnet/nfc/llcp_core.c-498-\nnet/nfc/llcp_core.c:499:\t\tlocal_ssap = ssap - LLCP_WKS_NUM_SAP;\nnet/nfc/llcp_core.c-500-\t\tsdp = \u0026local-\u003elocal_sdp;\n--\nnet/nfc/llcp_core.c-514-\t\t\t/ Find the listening sock and set it back to UNBOUND /\nnet/nfc/llcp_core.c:515:\t\t\tl_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);\nnet/nfc/llcp_core.c-516-\t\t\tif (l_sock) {\nnet/nfc/llcp_core.c:517:\t\t\t\tl_sock-\u003essap = LLCP_SDP_UNBOUND;\nnet/nfc/llcp_core.c-518-\t\t\t\tnfc_llcp_sock_put(l_sock);\n--\nnet/nfc/llcp_core.c-524-\t\treturn;\nnet/nfc/llcp_core.c:525:\t} else if (ssap \u003c LLCP_MAX_SAP) {\nnet/nfc/llcp_core.c:526:\t\tlocal_ssap = ssap - LLCP_LOCAL_NUM_SAP;\nnet/nfc/llcp_core.c-527-\t\tsdp = \u0026local-\u003elocal_sap;\n--\nnet/nfc/llcp_core.c=539=static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local local)\n--\nnet/nfc/llcp_core.c-544-\nnet/nfc/llcp_core.c:545:\tssap = find_first_zero_bit(\u0026local-\u003elocal_sdp, LLCP_SDP_NUM_SAP);\nnet/nfc/llcp_core.c:546:\tif (ssap == LLCP_SDP_NUM_SAP) {\nnet/nfc/llcp_core.c-547-\t\tmutex_unlock(\u0026local-\u003esdp_lock);\nnet/nfc/llcp_core.c-548-\nnet/nfc/llcp_core.c:549:\t\treturn LLCP_SAP_MAX;\nnet/nfc/llcp_core.c-550-\t}\nnet/nfc/llcp_core.c-551-\nnet/nfc/llcp_core.c:552:\tpr_debug(\"SDP ssap %d\\n\", LLCP_WKS_NUM_SAP + ssap);\nnet/nfc/llcp_core.c-553-\n--\nnet/nfc/llcp_core.c-557-\nnet/nfc/llcp_core.c:558:\treturn LLCP_WKS_NUM_SAP + ssap;\nnet/nfc/llcp_core.c-559-}\n--\nnet/nfc/llcp_core.c=561=static int nfc_llcp_build_gb(struct nfc_llcp_local local)\n--\nnet/nfc/llcp_core.c-570-\nnet/nfc/llcp_core.c:571:\tversion = LLCP_VERSION_11;\nnet/nfc/llcp_core.c:572:\tversion_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, \u0026version,\nnet/nfc/llcp_core.c-573-\t\t\t\t\t 1, \u0026version_length);\n--\nnet/nfc/llcp_core.c-579-\nnet/nfc/llcp_core.c:580:\tlto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, \u0026local-\u003elto, 1, \u0026lto_length);\nnet/nfc/llcp_core.c-581-\tif (!lto_tlv) {\n--\nnet/nfc/llcp_core.c-587-\tpr_debug(\"Local wks 0x%lx\\n\", local-\u003elocal_wks);\nnet/nfc/llcp_core.c:588:\twks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 )\u0026wks, 2, \u0026wks_length);\nnet/nfc/llcp_core.c-589-\tif (!wks_tlv) {\n--\nnet/nfc/llcp_core.c-594-\nnet/nfc/llcp_core.c:595:\tmiux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 )\u0026local-\u003emiux, 0,\nnet/nfc/llcp_core.c-596-\t\t\t\t \u0026miux_length);\n--\nnet/nfc/llcp_core.c=657=int nfc_llcp_set_remote_gb(struct nfc_dev dev, const u8 gb, u8 gb_len)\n--\nnet/nfc/llcp_core.c-666-\tif (local == NULL) {\nnet/nfc/llcp_core.c:667:\t\tpr_err(\"No LLCP device\\n\");\nnet/nfc/llcp_core.c-668-\t\treturn -ENODEV;\n--\nnet/nfc/llcp_core.c-675-\tif (memcmp(local-\u003eremote_gb, llcp_magic, 3)) {\nnet/nfc/llcp_core.c:676:\t\tpr_err(\"MAC does not support LLCP\\n\");\nnet/nfc/llcp_core.c-677-\t\terr = -EINVAL;\n--\nnet/nfc/llcp_core.c=721=void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-730-\tsk_for_each(sk, \u0026local-\u003eraw_sockets.head) {\nnet/nfc/llcp_core.c:731:\t\tif (sk-\u003esk_state != LLCP_BOUND)\nnet/nfc/llcp_core.c-732-\t\t\tcontinue;\n--\nnet/nfc/llcp_core.c-744-\t\t\tdata[1] = direction \u0026 0x01;\nnet/nfc/llcp_core.c:745:\t\t\tdata[1] \|= (RAW_PAYLOAD_LLCP \u003c\u003c 1);\nnet/nfc/llcp_core.c-746-\t\t}\n--\nnet/nfc/llcp_core.c=761=static void nfc_llcp_tx_work(struct work_struct work)\n--\nnet/nfc/llcp_core.c-773-\nnet/nfc/llcp_core.c:774:\t\tif (llcp_sock == NULL \u0026\u0026 nfc_llcp_ptype(skb) == LLCP_PDU_I) {\nnet/nfc/llcp_core.c-775-\t\t\tkfree_skb(skb);\n--\nnet/nfc/llcp_core.c-785-\t\t\tpr_debug(\"Sending pending skb\\n\");\nnet/nfc/llcp_core.c:786:\t\t\tprint_hex_dump_debug(\"LLCP Tx: \", DUMP_PREFIX_OFFSET,\nnet/nfc/llcp_core.c-787-\t\t\t\t\t 16, 1, skb-\u003edata, skb-\u003elen, true);\nnet/nfc/llcp_core.c-788-\nnet/nfc/llcp_core.c:789:\t\t\tif (ptype == LLCP_PDU_I)\nnet/nfc/llcp_core.c-790-\t\t\t\tcopy_skb = skb_copy(skb, GFP_ATOMIC);\n--\nnet/nfc/llcp_core.c-804-\nnet/nfc/llcp_core.c:805:\t\t\tif (ptype == LLCP_PDU_I \u0026\u0026 copy_skb)\nnet/nfc/llcp_core.c-806-\t\t\t\tskb_queue_tail(\u0026llcp_sock-\u003etx_pending_queue,\n--\nnet/nfc/llcp_core.c=849=static const u8 nfc_llcp_connect_sn(const struct sk_buff skb, size_t sn_len)\n--\nnet/nfc/llcp_core.c-851-\tu8 type, length;\nnet/nfc/llcp_core.c:852:\tconst u8 tlv = \u0026skb-\u003edata[LLCP_HEADER_SIZE];\nnet/nfc/llcp_core.c-853-\tconst u8 tlv_end = skb_tail_pointer(skb);\n--\nnet/nfc/llcp_core.c-863-\nnet/nfc/llcp_core.c:864:\t\tif (type == LLCP_TLV_SN) {\nnet/nfc/llcp_core.c-865-\t\t\tsn_len = length;\n--\nnet/nfc/llcp_core.c=875=static void nfc_llcp_recv_ui(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-891-\t/* We're looking for a bound socket, not a client one /\nnet/nfc/llcp_core.c:892:\tllcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);\nnet/nfc/llcp_core.c-893-\tif (llcp_sock == NULL \|\| llcp_sock-\u003esk.sk_type != SOCK_DGRAM)\n--\nnet/nfc/llcp_core.c-896-\t/ There is no sequence with UI frames /\nnet/nfc/llcp_core.c:897:\tskb_pull(skb, LLCP_HEADER_SIZE);\nnet/nfc/llcp_core.c-898-\tif (!sock_queue_rcv_skb(\u0026llcp_sock-\u003esk, skb)) {\n--\nnet/nfc/llcp_core.c=911=static void nfc_llcp_recv_connect(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-922-\nnet/nfc/llcp_core.c:923:\tif (dsap != LLCP_SAP_SDP) {\nnet/nfc/llcp_core.c:924:\t\tsock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);\nnet/nfc/llcp_core.c:925:\t\tif (sock == NULL \|\| sock-\u003esk.sk_state != LLCP_LISTEN) {\nnet/nfc/llcp_core.c:926:\t\t\treason = LLCP_DM_NOBOUND;\nnet/nfc/llcp_core.c-927-\t\t\tgoto fail;\n--\nnet/nfc/llcp_core.c-934-\t\tif (sn == NULL) {\n\n" }
37/2	2026/09/27 14:17	llm	patch-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 43687 output: 113 thoughts: 1102 Thoughts: Analysis of LLCP Socket Connect for Fuzzing Okay, so I'm looking at this patch and figuring out the best way to fuzz it effectively. First, it looks like `llcp_sock.c` is compiled when `CONFIG_NFC` is enabled, and there aren't any sub-configs like `CONFIG_NFC_LLCP`. The `nfc.ko` module itself gets built directly with `CONFIG_NFC`, which simplifies things. The relevant Makefile confirms this: `obj-$(CONFIG_NFC) += nfc.o` and `nfc-objs := ... llcp_sock.o`. Checking `net/nfc/Kconfig`, it's clear that `CONFIG_NFC` itself is the only config needed, and it depends on `RFKILL \|\| !RFKILL`, which is pretty common. Now, focusing on the modified function, it's `llcp_sock_connect`. No other functions are directly modified in the patch, so that's the primary entry point to consider. The patch modifies `llcp_sock_connect` in `net/nfc/llcp_sock.c`. Inside the new logic, the code is calling `nfc_llcp_put_ssap`, `nfc_llcp_local_put`, and `nfc_put_device`. These aren't generic hot-path functions, but specific to NFC LLCP, and NFC in general. `llcp_sock_connect` is the direct API entry point for `connect()` calls on LLCP sockets, making it the perfect target. It's the point where the logic is added and modified. `llcp_sock_connect` is defined as `static int llcp_sock_connect(...)`, and it's a function pointer in the `proto_ops` struct (`.connect = llcp_sock_connect`). So, it's not going to be inlined and will definitely have a symbol, something like `llcp_sock_connect.isra.0` or just `llcp_sock_connect`. I considered checking related functions in `llcp_sock.c` like `llcp_sock_bind`, `llcp_sock_release`, and `llcp_sock_destruct`, but according to the FocusSymbols rule, `llcp_sock_connect` is the exact function implementing the added logic and it's a direct API entrypoint. Now, should we fuzz this? Absolutely. Reachable executable code is modified: `llcp_sock_connect`. It's reachable via a standard userspace `socket(PF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP)` and then `connect()` call. The patch alters state management and resource cleanup. It frees resources (SAP, local, dev, service_name) on reconnect when `sk->sk_state == LLCP_CLOSED`. This is ripe for regressions: double-frees, use-after-frees, and refcount underflows. Issues could arise if `llcp_sock->local` has already been freed, with `nfc_llcp_put_ssap` receiving invalid input, or with concurrency between reconnects and other threads. So, here's my verdict: * WorthFuzzing: true * EnableConfigs: \[“NFC”] * FocusSymbols: \[“llcp_sock_connect”] Everything checks out. Time to `set-results`.
38/2	2026/09/27 14:17	tool	set-results	0m Args: { "EnableConfigs": [ "NFC" ], "FocusSymbols": [ "llcp_sock_connect" ], "Reasoning": "The patch modifies resource cleanup logic in llcp_sock_connect() for NFC LLCP sockets when transitioning or reconnecting from LLCP_CLOSED state. This reachable network socket path is accessible from unprivileged userspace via the AF_NFC socket API and warrants fuzzing for potential refcount bugs, double-frees, or state management issues.", "WorthFuzzing": true } Results: { "EnableConfigs": [ "NFC" ], "FocusSymbols": [ "llcp_sock_connect" ], "Reasoning": "The patch modifies resource cleanup logic in llcp_sock_connect() for NFC LLCP sockets when transitioning or reconnecting from LLCP_CLOSED state. This reachable network socket path is accessible from unprivileged userspace via the AF_NFC socket API and warrants fuzzing for potential refcount bugs, double-frees, or state management issues.", "WorthFuzzing": true }
39/1	2026/09/27 14:17	action	If	0m Args: { "WorthFuzzing": true } Results: null
40/2	2026/09/27 14:17	agent	kmsan-evaluator	0m Model: core Args: null Results: { "KMSANReasoning": "The patch modifies `llcp_sock_connect()` in `net/nfc/llcp_sock.c` to release retained resources (such as dropped device/local references, SSAP, and service name memory) when reconnecting a socket in the `LLCP_CLOSED` state.\n\n1. KMSAN applicability: The changes only free allocated resources (`kfree`, `nfc_put_device`, `nfc_llcp_local_put`, `nfc_llcp_put_ssap`) and reset pointer and integer fields on the socket struct (`local`, `dev`, `service_name`, `service_name_len`, `reserved_ssap`). No new uninitialized stack or heap allocations are introduced, no uninitialized variables or struct padding are read or branched on, and no data is copied to user space.\n2. KASAN and standard sanitizers: The bugs potentially associated with this cleanup logic involve refcounting errors, double-frees, or use-after-free conditions on the socket/device structures, which are detected by KASAN, refcount tracking, or standard kernel debuggers.\n\nTherefore, a dedicated KMSAN fuzzing session is not warranted.", "NeedsKMSAN": false } Instruction: 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. Prompt: Target architecture: amd64 For your convenience, here is the diff of the changes: commit cc5b0edd1f67a160a2ff81be680294718ecd25df Author: syz-cluster <triage@syzkaller.com> Date: Sun Sep 27 14:15:43 2026 +0000 syz-cluster: applied patch under review diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index 5558d8a4d48b3..e76361e5ef166 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -690,6 +690,23 @@ static int llcp_sock_connect(struct socket sock, struct sockaddr_unsized _addr goto error; } + if (sk->sk_state == LLCP_CLOSED) { + /* Release resources retained by a previous failed connection. */ + if (llcp_sock->local) { + if (llcp_sock->reserved_ssap < LLCP_SAP_MAX) + nfc_llcp_put_ssap(llcp_sock->local, llcp_sock->ssap); + nfc_llcp_local_put(llcp_sock->local); + } + if (llcp_sock->dev) + nfc_put_device(llcp_sock->dev); + kfree(llcp_sock->service_name); + llcp_sock->local = NULL; + llcp_sock->dev = NULL; + llcp_sock->service_name = NULL; + llcp_sock->service_name_len = 0; + llcp_sock->reserved_ssap = LLCP_SAP_MAX; + } + dev = nfc_get_device(addr->dev_idx); if (dev == NULL) { ret = -ENODEV;
41/3	2026/09/27 14:17	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 2296 output: 39 thoughts: 56 Thoughts: Okay, here's my interpretation of that thought process, tailored for an expert audience: Analyzing a Potential NFC LLCP Socket Patch Right, let's dive in. My initial thought is to zero in on this patch. I need to understand its impact within the `net/nfc/llcp_sock.c` context. Given my experience, the first step is to quickly orient myself. I'll need to read the diff and then likely pull up the target file, which I expect is `net/nfc/llcp_sock.c`, to get a feel for the surrounding code. Then, I'm going to leverage my familiarity with the kernel build system and debugging tools. I'm thinking, "Let's use `read-file` to zero in on the area around line 690 in that file." This is the key. I expect that line 690 is the likely target of the patch or code that is associated. I'll need to rapidly understand its role within the larger framework and whether there is something to fix.
42/3	2026/09/27 14:17	tool	read-file	0m Args: { "File": "net/nfc/llcp_sock.c", "FirstLine": 660, "LineCount": 80 } Results: { "Contents": " 660:\t\n 661:\tstatic int llcp_sock_connect(struct socket sock, struct sockaddr_unsized _addr,\n 662:\t\t\t\t int len, int flags)\n 663:\t{\n 664:\t\tstruct sock sk = sock-\u003esk;\n 665:\t\tstruct nfc_llcp_sock llcp_sock = nfc_llcp_sock(sk);\n 666:\t\tstruct sockaddr_nfc_llcp addr = (struct sockaddr_nfc_llcp )_addr;\n 667:\t\tstruct nfc_dev dev;\n 668:\t\tstruct nfc_llcp_local local;\n 669:\t\tint ret = 0;\n 670:\t\n 671:\t\tpr_debug(\"sock %p sk %p flags 0x%x\\n\", sock, sk, flags);\n 672:\t\n 673:\t\tif (!addr \|\| len \u003c sizeof(addr) \|\| addr-\u003esa_family != AF_NFC)\n 674:\t\t\treturn -EINVAL;\n 675:\t\n 676:\t\tif (addr-\u003eservice_name_len == 0 \u0026\u0026 addr-\u003edsap == 0)\n 677:\t\t\treturn -EINVAL;\n 678:\t\n 679:\t\tpr_debug(\"addr dev_idx=%u target_idx=%u protocol=%u\\n\", addr-\u003edev_idx,\n 680:\t\t\t addr-\u003etarget_idx, addr-\u003enfc_protocol);\n 681:\t\n 682:\t\tlock_sock(sk);\n 683:\t\n 684:\t\tif (sk-\u003esk_state == LLCP_CONNECTED) {\n 685:\t\t\tret = -EISCONN;\n 686:\t\t\tgoto error;\n 687:\t\t}\n 688:\t\tif (sk-\u003esk_state == LLCP_CONNECTING) {\n 689:\t\t\tret = -EINPROGRESS;\n 690:\t\t\tgoto error;\n 691:\t\t}\n 692:\t\n 693:\t\tif (sk-\u003esk_state == LLCP_CLOSED) {\n 694:\t\t\t/ Release resources retained by a previous failed connection. */\n 695:\t\t\tif (llcp_sock-\u003elocal) {\n 696:\t\t\t\tif (llcp_sock-\u003ereserved_ssap \u003c LLCP_SAP_MAX)\n 697:\t\t\t\t\tnfc_llcp_put_ssap(llcp_sock-\u003elocal, llcp_sock-\u003essap);\n 698:\t\t\t\tnfc_llcp_local_put(llcp_sock-\u003elocal);\n 699:\t\t\t}\n 700:\t\t\tif (llcp_sock-\u003edev)\n 701:\t\t\t\tnfc_put_device(llcp_sock-\u003edev);\n 702:\t\t\tkfree(llcp_sock-\u003eservice_name);\n 703:\t\t\tllcp_sock-\u003elocal = NULL;\n 704:\t\t\tllcp_sock-\u003edev = NULL;\n 705:\t\t\tllcp_sock-\u003eservice_name = NULL;\n 706:\t\t\tllcp_sock-\u003eservice_name_len = 0;\n 707:\t\t\tllcp_sock-\u003ereserved_ssap = LLCP_SAP_MAX;\n 708:\t\t}\n 709:\t\n 710:\t\tdev = nfc_get_device(addr-\u003edev_idx);\n 711:\t\tif (dev == NULL) {\n 712:\t\t\tret = -ENODEV;\n 713:\t\t\tgoto error;\n 714:\t\t}\n 715:\t\n 716:\t\tlocal = nfc_llcp_find_local(dev);\n 717:\t\tif (local == NULL) {\n 718:\t\t\tret = -ENODEV;\n 719:\t\t\tgoto put_dev;\n 720:\t\t}\n 721:\t\n 722:\t\tdevice_lock(\u0026dev-\u003edev);\n 723:\t\tif (dev-\u003edep_link_up == false) {\n 724:\t\t\tret = -ENOLINK;\n 725:\t\t\tdevice_unlock(\u0026dev-\u003edev);\n 726:\t\t\tgoto sock_llcp_put_local;\n 727:\t\t}\n 728:\t\tdevice_unlock(\u0026dev-\u003edev);\n 729:\t\n 730:\t\tif (local-\u003erf_mode == NFC_RF_INITIATOR \u0026\u0026\n 731:\t\t addr-\u003etarget_idx != local-\u003etarget_idx) {\n 732:\t\t\tret = -ENOLINK;\n 733:\t\t\tgoto sock_llcp_put_local;\n 734:\t\t}\n 735:\t\n 736:\t\tllcp_sock-\u003edev = dev;\n 737:\t\tllcp_sock-\u003elocal = local;\n 738:\t\tllcp_sock-\u003essap = nfc_llcp_get_local_ssap(local);\n 739:\t\tif (llcp_sock-\u003essap == LLCP_SAP_MAX) {\n" }
43/3	2026/09/27 14:17	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 3899 output: 39 thoughts: 25 Thoughts: Okay, here's my interpretation of that thought process, tailored for an expert audience, and written in the first person: Diving into `llcp_sock_connect` - A Closer Look Alright, I'm thinking we need to dig a little deeper into the `llcp_sock_connect` function. I'm suspecting there might be something interesting happening around line 739, and potentially earlier in that routine. I'll need to trace the execution flow and see exactly what's going on there with the connection establishment. My guess is there might be some interaction with the internal state machine that will be of interest. Perhaps something like a race condition or a subtle edge case is in play. Time to get the debugger fired up and step through the code! I'm going to pay close attention to the state transitions and any potential synchronization primitives used. I'll be particularly interested in how errors are handled in that region.
44/3	2026/09/27 14:17	tool	read-file	0m Args: { "File": "net/nfc/llcp_sock.c", "FirstLine": 735, "LineCount": 60 } Results: { "Contents": " 735:\t\n 736:\t\tllcp_sock-\u003edev = dev;\n 737:\t\tllcp_sock-\u003elocal = local;\n 738:\t\tllcp_sock-\u003essap = nfc_llcp_get_local_ssap(local);\n 739:\t\tif (llcp_sock-\u003essap == LLCP_SAP_MAX) {\n 740:\t\t\tret = -ENOMEM;\n 741:\t\t\tgoto sock_llcp_nullify;\n 742:\t\t}\n 743:\t\n 744:\t\tllcp_sock-\u003ereserved_ssap = llcp_sock-\u003essap;\n 745:\t\n 746:\t\tif (addr-\u003eservice_name_len == 0)\n 747:\t\t\tllcp_sock-\u003edsap = addr-\u003edsap;\n 748:\t\telse\n 749:\t\t\tllcp_sock-\u003edsap = LLCP_SAP_SDP;\n 750:\t\tllcp_sock-\u003enfc_protocol = addr-\u003enfc_protocol;\n 751:\t\tllcp_sock-\u003eservice_name_len = min_t(unsigned int,\n 752:\t\t\t\t\t\t addr-\u003eservice_name_len,\n 753:\t\t\t\t\t\t NFC_LLCP_MAX_SERVICE_NAME);\n 754:\t\tllcp_sock-\u003eservice_name = kmemdup(addr-\u003eservice_name,\n 755:\t\t\t\t\t\t llcp_sock-\u003eservice_name_len,\n 756:\t\t\t\t\t\t GFP_KERNEL);\n 757:\t\tif (!llcp_sock-\u003eservice_name) {\n 758:\t\t\tret = -ENOMEM;\n 759:\t\t\tgoto sock_llcp_release;\n 760:\t\t}\n 761:\t\n 762:\t\tnfc_llcp_sock_link(\u0026local-\u003econnecting_sockets, sk);\n 763:\t\n 764:\t\tret = nfc_llcp_send_connect(llcp_sock);\n 765:\t\tif (ret)\n 766:\t\t\tgoto sock_unlink;\n 767:\t\n 768:\t\tsk-\u003esk_state = LLCP_CONNECTING;\n 769:\t\n 770:\t\tret = sock_wait_state(sk, LLCP_CONNECTED,\n 771:\t\t\t\t sock_sndtimeo(sk, flags \u0026 O_NONBLOCK));\n 772:\t\tif (ret \u0026\u0026 ret != -EINPROGRESS)\n 773:\t\t\tgoto sock_unlink;\n 774:\t\n 775:\t\trelease_sock(sk);\n 776:\t\n 777:\t\treturn ret;\n 778:\t\n 779:\tsock_unlink:\n 780:\t\tnfc_llcp_sock_unlink(\u0026local-\u003econnecting_sockets, sk);\n 781:\t\tkfree(llcp_sock-\u003eservice_name);\n 782:\t\tllcp_sock-\u003eservice_name = NULL;\n 783:\t\n 784:\tsock_llcp_release:\n 785:\t\tnfc_llcp_put_ssap(local, llcp_sock-\u003essap);\n 786:\t\n 787:\tsock_llcp_nullify:\n 788:\t\tllcp_sock-\u003elocal = NULL;\n 789:\t\tllcp_sock-\u003edev = NULL;\n 790:\t\n 791:\tsock_llcp_put_local:\n 792:\t\tnfc_llcp_local_put(local);\n 793:\t\n 794:\tput_dev:\n" }
45/3	2026/09/27 14:17	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 5088 output: 31 thoughts: 477 Thoughts: Analyzing the Resource Cleanup in `llcp_sock_connect` Okay, so I'm looking at this patch for `llcp_sock_connect`. My initial thought is to understand how it handles resources in the event of a failed or disconnected connection. Specifically, I'm concerned with the state when `sk_state` is `LLCP_CLOSED`, which arises after failure or an `-EINPROGRESS` return. In this state, the code seems to release resources that are still referenced by the `llcp_sock` structure – things like `service_name`, `dev`, `local`, and `reserved_ssap`. The core logic here, as I understand it, is to clean up these resources within a conditional block: `if (sk->sk_state == LLCP_CLOSED)`. The patch then proceeds to: 1. Release `local` resources, including the SSAP if one was reserved. 2. Release the device (`dev`). 3. Free the `service_name` string. 4. Reset the relevant fields in `llcp_sock` (e.g., setting `local` and `dev` to NULL, `service_name` to NULL, and so on). Now, my primary focus shifts to ensuring that this doesn't introduce any uninitialized memory risks. Is this cleanup code done correctly? Specifically, am I missing some resource that has to be cleaned up? Is it releasing resources in the correct order? Does the patch itself read from uninitialized memory? I need to analyze the initialization of `llcp_sock` to get a complete picture. Are there any other paths to get to this cleanup function? I need to confirm that after this cleanup, everything is properly initialized before a subsequent `connect()` call, especially because it's possible the user may call `connect()` again when `sk->sk_state == LLCP_CLOSED`. I'll have to investigate how the `llcp_sock` is initialized elsewhere to ensure the reset values are valid. This is all about preventing future problems or subtle bugs.
46/3	2026/09/27 14:17	tool	grepper	0m Args: { "Expression": "llcp_sock_alloc", "PathPrefix": "net/nfc/" } Results: { "Output": "net/nfc/llcp.h=210=void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local local,\n--\nnet/nfc/llcp.h-213-/ Sock API /\nnet/nfc/llcp.h:214:struct sock nfc_llcp_sock_alloc(struct socket sock, int type, gfp_t gfp, int kern);\nnet/nfc/llcp.h-215-void nfc_llcp_sock_free(struct nfc_llcp_sock sock);\n--\nnet/nfc/llcp_core.c=911=static void nfc_llcp_recv_connect(struct nfc_llcp_local local,\n--\nnet/nfc/llcp_core.c-973-\nnet/nfc/llcp_core.c:974:\tnew_sk = nfc_llcp_sock_alloc(NULL, parent-\u003esk_type, GFP_ATOMIC, 0);\nnet/nfc/llcp_core.c-975-\tif (new_sk == NULL) {\n--\nnet/nfc/llcp_sock.c=982=static void llcp_sock_destruct(struct sock sk)\n--\nnet/nfc/llcp_sock.c-1000-\nnet/nfc/llcp_sock.c:1001:struct sock nfc_llcp_sock_alloc(struct socket sock, int type, gfp_t gfp, int kern)\nnet/nfc/llcp_sock.c-1002-{\n--\nnet/nfc/llcp_sock.c=1051=static int llcp_sock_create(struct net net, struct socket sock,\n--\nnet/nfc/llcp_sock.c-1070-\nnet/nfc/llcp_sock.c:1071:\tsk = nfc_llcp_sock_alloc(sock, sock-\u003etype, GFP_ATOMIC, kern);\nnet/nfc/llcp_sock.c-1072-\tif (sk == NULL)\n" }
47/3	2026/09/27 14:17	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 6577 output: 40 thoughts: 29 Thoughts: Okay, let's dive into this. Here's my take on examining that function: Inspecting `nfc_llcp_sock_alloc` Alright, time to get to it. I want to take a closer look at the `nfc_llcp_sock_alloc` function. I remember seeing that one in `net/nfc/llcp_sock.c`. Given the naming, it's pretty clear that this function is responsible for allocating an LLCP socket within the NFC subsystem. My understanding is it's the foundation of the connection. I'll need to scrutinize how it handles memory allocation, initialization of the socket structure, and any potential locking or synchronization involved. I'll also be looking for any error conditions that are handled and how they are reported. I want to see how robustly this critical function is written to ensure the reliability of LLCP connections. It should be relatively straightforward, but I'll make sure to double-check any pointers and data structures it works with. After all, the socket allocation is a core part of the LLCP stack. Let's see how things are initialized and how the structure is set up.
48/3	2026/09/27 14:17	tool	read-file	0m Args: { "File": "net/nfc/llcp_sock.c", "FirstLine": 1000, "LineCount": 45 } Results: { "Contents": "1000:\t\n1001:\tstruct sock nfc_llcp_sock_alloc(struct socket sock, int type, gfp_t gfp, int kern)\n1002:\t{\n1003:\t\tstruct sock sk;\n1004:\t\tstruct nfc_llcp_sock llcp_sock;\n1005:\t\n1006:\t\tsk = sk_alloc(\u0026init_net, PF_NFC, gfp, \u0026llcp_sock_proto, kern);\n1007:\t\tif (!sk)\n1008:\t\t\treturn NULL;\n1009:\t\n1010:\t\tllcp_sock = nfc_llcp_sock(sk);\n1011:\t\n1012:\t\tsock_init_data(sock, sk);\n1013:\t\tsk-\u003esk_state = LLCP_CLOSED;\n1014:\t\tsk-\u003esk_protocol = NFC_SOCKPROTO_LLCP;\n1015:\t\tsk-\u003esk_type = type;\n1016:\t\tsk-\u003esk_destruct = llcp_sock_destruct;\n1017:\t\n1018:\t\tllcp_sock-\u003essap = 0;\n1019:\t\tllcp_sock-\u003edsap = LLCP_SAP_SDP;\n1020:\t\tllcp_sock-\u003erw = LLCP_MAX_RW + 1;\n1021:\t\tllcp_sock-\u003emiux = cpu_to_be16(LLCP_MAX_MIUX + 1);\n1022:\t\tllcp_sock-\u003esend_n = llcp_sock-\u003esend_ack_n = 0;\n1023:\t\tllcp_sock-\u003erecv_n = llcp_sock-\u003erecv_ack_n = 0;\n1024:\t\tllcp_sock-\u003eremote_ready = 1;\n1025:\t\tllcp_sock-\u003ereserved_ssap = LLCP_SAP_MAX;\n1026:\t\tnfc_llcp_socket_remote_param_init(llcp_sock);\n1027:\t\tskb_queue_head_init(\u0026llcp_sock-\u003etx_queue);\n1028:\t\tskb_queue_head_init(\u0026llcp_sock-\u003etx_pending_queue);\n1029:\t\tINIT_LIST_HEAD(\u0026llcp_sock-\u003eaccept_queue);\n1030:\t\n1031:\t\tif (sock != NULL)\n1032:\t\t\tsock-\u003estate = SS_UNCONNECTED;\n1033:\t\n1034:\t\treturn sk;\n1035:\t}\n1036:\t\n1037:\tvoid nfc_llcp_sock_free(struct nfc_llcp_sock *sock)\n1038:\t{\n1039:\t\tkfree(sock-\u003eservice_name);\n1040:\t\n1041:\t\tskb_queue_purge(\u0026sock-\u003etx_queue);\n1042:\t\tskb_queue_purge(\u0026sock-\u003etx_pending_queue);\n1043:\t\n1044:\t\tlist_del_init(\u0026sock-\u003eaccept_queue);\n" }
49/3	2026/09/27 14:17	llm	kmsan-evaluator	0m Model: gemini-3.8-flash Args: null Results: null Tokens: input: 7689 output: 276 thoughts: 731 Thoughts: My Assessment of the Patch's Safety Okay, let me break down this patch and determine if it warrants a KMSAN check. My initial impression, after carefully reviewing the code and its changes, is that it's likely safe from uninitialized memory access issues. Here's my thought process: First, `sk_alloc` is responsible for allocating and zero-initializing the socket structure. This is a critical first step. Zero-initialization, either through `kmem_cache_alloc` with zeroing or `memset`, is key to preventing uninitialized memory reads. Further down the line, I can see that in `nfc_llcp_sock_alloc`, the `reserved_ssap` field is initialized, and `local`, `dev`, and `service_name` are set to NULL/0 due to zeroing. The core of the patch involves a check in `llcp_sock_connect` on the socket's state (`sk->sk_state`). If the socket is in the `LLCP_CLOSED` state, it cleans up resources and resets fields. Now, does any of this introduce a risk related to uninitialized variables? Absolutely not. The code meticulously handles initialization, whether it’s at allocation or through state transitions. I'm seeing that the patch is careful about resource management. It's only freeing memory using `kfree` and dropping refcounts using functions like `nfc_llcp_put_ssap`, `nfc_llcp_local_put`, and `nfc_put_device`. This suggests a focus on preventing resource leaks. Now, let's address the crucial KMSAN criteria: * Does this touch user-copy logic? No. * Does it leave any uninitialized variables? No. * Does it copy any uninitialized fields to user space? No. * Does it branch on uninitialized data? No. All of these are crucial because KMSAN specifically targets reads of uninitialized memory and the leaking of uninitialized data to userspace. In this case, `sk->sk_state`, `llcp_sock->local`, `llcp_sock->reserved_ssap`, and all other relevant fields are correctly initialized at either socket creation or during state transitions. The potential bugs this patch could touch are around resource leaks, use-after-free, double-free and state machine bugs. However, these are things like KASAN, refcount_t, SLUB, and KMEMLEAK, not KMSAN. KMSAN is for detecting the kinds of issues that this patch doesn't seem to have. Finally, let's go back and explicitly check the prompt criteria for `NeedsKMSAN`. 1. No kernel structures are being sent to user space. 2. No conditional logic depends on potentially uninitialized data. 3. No allocation of complex data structures with uninitialized fields. 4. No bounds checks that expose uninitialized bytes. Therefore, since all structures are correctly initialized (zeroed or otherwise), and there is no risk of exposing uninitialized data, this patch definitely doesn't require KMSAN. The changes are focused on resource management, which are covered by KASAN/refcount_t/SLUB/KMEMLEAK. Thus, the call should be `set-results(NeedsKMSAN=false)`.
50/3	2026/09/27 14:17	tool	set-results	0m Args: { "KMSANReasoning": "The patch modifies `llcp_sock_connect()` in `net/nfc/llcp_sock.c` to release retained resources (such as dropped device/local references, SSAP, and service name memory) when reconnecting a socket in the `LLCP_CLOSED` state.\n\n1. KMSAN applicability: The changes only free allocated resources (`kfree`, `nfc_put_device`, `nfc_llcp_local_put`, `nfc_llcp_put_ssap`) and reset pointer and integer fields on the socket struct (`local`, `dev`, `service_name`, `service_name_len`, `reserved_ssap`). No new uninitialized stack or heap allocations are introduced, no uninitialized variables or struct padding are read or branched on, and no data is copied to user space.\n2. KASAN and standard sanitizers: The bugs potentially associated with this cleanup logic involve refcounting errors, double-frees, or use-after-free conditions on the socket/device structures, which are detected by KASAN, refcount tracking, or standard kernel debuggers.\n\nTherefore, a dedicated KMSAN fuzzing session is not warranted.", "NeedsKMSAN": false } Results: { "KMSANReasoning": "The patch modifies `llcp_sock_connect()` in `net/nfc/llcp_sock.c` to release retained resources (such as dropped device/local references, SSAP, and service name memory) when reconnecting a socket in the `LLCP_CLOSED` state.\n\n1. KMSAN applicability: The changes only free allocated resources (`kfree`, `nfc_put_device`, `nfc_llcp_local_put`, `nfc_llcp_put_ssap`) and reset pointer and integer fields on the socket struct (`local`, `dev`, `service_name`, `service_name_len`, `reserved_ssap`). No new uninitialized stack or heap allocations are introduced, no uninitialized variables or struct padding are read or branched on, and no data is copied to user space.\n2. KASAN and standard sanitizers: The bugs potentially associated with this cleanup logic involve refcounting errors, double-frees, or use-after-free conditions on the socket/device structures, which are detected by KASAN, refcount tracking, or standard kernel debuggers.\n\nTherefore, a dedicated KMSAN fuzzing session is not warranted.", "NeedsKMSAN": false }

LLM Calls Summary:
Total Calls	Total Tokens	Avg Tokens	Total Duration (Seconds)	Avg Duration (Seconds)

Tool Calls Summary:
Total Calls	Total Duration (Seconds)	Avg Duration (Seconds)