AI Trajectory

null

{
  "EnableConfigs": [
    "NFC_NCI",
    "NFC_VIRTUAL_NCI"
  ],
  "FocusSymbols": [
    "nci_core_init_rsp_packet_v1",
    "nci_core_init_rsp_packet_v2"
  ],
  "Reasoning": "The patch adds length checks to NCI core init response packets parsing to prevent out-of-bounds reads. This is a functional change fixing potential memory safety issues.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit b175276ce3498cda7848d0e7d2edb720ea5569c4\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Tue Jun 23 22:41:17 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/nfc/nci/rsp.c b/net/nfc/nci/rsp.c\nindex 9eeb862825c5fe..cdcd23c8ca95fe 100644\n--- a/net/nfc/nci/rsp.c\n+++ b/net/nfc/nci/rsp.c\n@@ -50,6 +50,9 @@ static u8 nci_core_init_rsp_packet_v1(struct nci_dev *ndev,\n \tconst struct nci_core_init_rsp_1 *rsp_1 = (void *)skb-\u003edata;\n \tconst struct nci_core_init_rsp_2 *rsp_2;\n \n+\tif (skb-\u003elen \u003c sizeof(*rsp_1))\n+\t\treturn NCI_STATUS_SYNTAX_ERROR;\n+\n \tpr_debug(\"status 0x%x\\n\", rsp_1-\u003estatus);\n \n \tif (rsp_1-\u003estatus != NCI_STATUS_OK)\n@@ -58,6 +61,15 @@ static u8 nci_core_init_rsp_packet_v1(struct nci_dev *ndev,\n \tndev-\u003enfcc_features = __le32_to_cpu(rsp_1-\u003enfcc_features);\n \tndev-\u003enum_supported_rf_interfaces = rsp_1-\u003enum_supported_rf_interfaces;\n \n+\t/*\n+\t * supported_rf_interfaces[] and the trailing nci_core_init_rsp_2 are\n+\t * addressed using the on-wire (unclamped) interface count, so the\n+\t * response must be long enough for both before they are dereferenced.\n+\t */\n+\tif (skb-\u003elen \u003c sizeof(*rsp_1) +\n+\t    rsp_1-\u003enum_supported_rf_interfaces + sizeof(*rsp_2))\n+\t\treturn NCI_STATUS_SYNTAX_ERROR;\n+\n \tndev-\u003enum_supported_rf_interfaces =\n \t\tmin((int)ndev-\u003enum_supported_rf_interfaces,\n \t\t    NCI_MAX_SUPPORTED_RF_INTERFACES);\n@@ -88,9 +100,13 @@ static u8 nci_core_init_rsp_packet_v2(struct nci_dev *ndev,\n {\n \tconst struct nci_core_init_rsp_nci_ver2 *rsp = (void *)skb-\u003edata;\n \tconst u8 *supported_rf_interface = rsp-\u003esupported_rf_interfaces;\n+\tconst u8 *end = skb-\u003edata + skb-\u003elen;\n \tu8 rf_interface_idx = 0;\n \tu8 rf_extension_cnt = 0;\n \n+\tif (skb-\u003elen \u003c sizeof(*rsp))\n+\t\treturn NCI_STATUS_SYNTAX_ERROR;\n+\n \tpr_debug(\"status %x\\n\", rsp-\u003estatus);\n \n \tif (rsp-\u003estatus != NCI_STATUS_OK)\n@@ -104,10 +120,16 @@ static u8 nci_core_init_rsp_packet_v2(struct nci_dev *ndev,\n \t\t    NCI_MAX_SUPPORTED_RF_INTERFACES);\n \n \twhile (rf_interface_idx \u003c ndev-\u003enum_supported_rf_interfaces) {\n-\t\tndev-\u003esupported_rf_interfaces[rf_interface_idx++] = *supported_rf_interface++;\n+\t\t/* one interface byte + one extension-count byte must be present */\n+\t\tif (end - supported_rf_interface \u003c 2)\n+\t\t\treturn NCI_STATUS_SYNTAX_ERROR;\n+\t\tndev-\u003esupported_rf_interfaces[rf_interface_idx++] =\n+\t\t\t*supported_rf_interface++;\n \n-\t\t/* skip rf extension parameters */\n+\t\t/* skip rf extension parameters, bounded by the packet */\n \t\trf_extension_cnt = *supported_rf_interface++;\n+\t\tif (rf_extension_cnt \u003e end - supported_rf_interface)\n+\t\t\treturn NCI_STATUS_SYNTAX_ERROR;\n \t\tsupported_rf_interface += rf_extension_cnt;\n \t}\n \n"
}

gemini-3.1-pro-preview

null

{
  "EnableConfigs": [
    "NFC_NCI",
    "NFC_VIRTUAL_NCI"
  ],
  "FocusSymbols": [
    "nci_core_init_rsp_packet_v1",
    "nci_core_init_rsp_packet_v2"
  ],
  "Reasoning": "The patch adds length checks to NCI core init response packets parsing to prevent out-of-bounds reads. This is a functional change fixing potential memory safety issues.",
  "WorthFuzzing": true
}

You are an expert Linux kernel maintainer.
Your job is to review a provided patch series and determine
if it makes functional changes to the kernel that should be fuzzed.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively
use your code access tools to examine the actual source code and confirm any assumptions.

Return WorthFuzzing=false if the patch only contains:
- Modifications to Documentation/, Kconfig files, or code comments.
- Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints.
- Changes to numeric constants or macros that do not functionally alter execution flow.
- Code paths that are impossible to reach in virtualized environments like GCE or QEMU,
even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim).

If it modifies reachable core kernel logic, drivers, or architectures, use your code search
tools to verify the code can be executed, then return WorthFuzzing=true.

When returning WorthFuzzing=true, you MUST ALSO:
1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols.
   Avoid listing generic hot-path functions to prevent skewed test distributions.
2. Identify any specific CONFIG_ options required to properly test this new/modified feature.
   Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions.
   Do not list too generic configs (we already have them enabled). Only list those that
   specifically cover the modified code. List them in the EnableConfigs output array,
   and DO NOT add a '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.

For your convenience, here is the diff of the changes:
commit b175276ce3498cda7848d0e7d2edb720ea5569c4
Author: syz-cluster <triage@syzkaller.com>
Date:   Tue Jun 23 22:41:17 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/nfc/nci/rsp.c b/net/nfc/nci/rsp.c
index 9eeb862825c5fe..cdcd23c8ca95fe 100644
--- a/net/nfc/nci/rsp.c
+++ b/net/nfc/nci/rsp.c
@@ -50,6 +50,9 @@ static u8 nci_core_init_rsp_packet_v1(struct nci_dev *ndev,
 	const struct nci_core_init_rsp_1 *rsp_1 = (void *)skb->data;
 	const struct nci_core_init_rsp_2 *rsp_2;
 
+	if (skb->len < sizeof(*rsp_1))
+		return NCI_STATUS_SYNTAX_ERROR;
+
 	pr_debug("status 0x%x\n", rsp_1->status);
 
 	if (rsp_1->status != NCI_STATUS_OK)
@@ -58,6 +61,15 @@ static u8 nci_core_init_rsp_packet_v1(struct nci_dev *ndev,
 	ndev->nfcc_features = __le32_to_cpu(rsp_1->nfcc_features);
 	ndev->num_supported_rf_interfaces = rsp_1->num_supported_rf_interfaces;
 
+	/*
+	 * supported_rf_interfaces[] and the trailing nci_core_init_rsp_2 are
+	 * addressed using the on-wire (unclamped) interface count, so the
+	 * response must be long enough for both before they are dereferenced.
+	 */
+	if (skb->len < sizeof(*rsp_1) +
+	    rsp_1->num_supported_rf_interfaces + sizeof(*rsp_2))
+		return NCI_STATUS_SYNTAX_ERROR;
+
 	ndev->num_supported_rf_interfaces =
 		min((int)ndev->num_supported_rf_interfaces,
 		    NCI_MAX_SUPPORTED_RF_INTERFACES);
@@ -88,9 +100,13 @@ static u8 nci_core_init_rsp_packet_v2(struct nci_dev *ndev,
 {
 	const struct nci_core_init_rsp_nci_ver2 *rsp = (void *)skb->data;
 	const u8 *supported_rf_interface = rsp->supported_rf_interfaces;
+	const u8 *end = skb->data + skb->len;
 	u8 rf_interface_idx = 0;
 	u8 rf_extension_cnt = 0;
 
+	if (skb->len < sizeof(*rsp))
+		return NCI_STATUS_SYNTAX_ERROR;
+
 	pr_debug("status %x\n", rsp->status);
 
 	if (rsp->status != NCI_STATUS_OK)
@@ -104,10 +120,16 @@ static u8 nci_core_init_rsp_packet_v2(struct nci_dev *ndev,
 		    NCI_MAX_SUPPORTED_RF_INTERFACES);
 
 	while (rf_interface_idx < ndev->num_supported_rf_interfaces) {
-		ndev->supported_rf_interfaces[rf_interface_idx++] = *supported_rf_interface++;
+		/* one interface byte + one extension-count byte must be present */
+		if (end - supported_rf_interface < 2)
+			return NCI_STATUS_SYNTAX_ERROR;
+		ndev->supported_rf_interfaces[rf_interface_idx++] =
+			*supported_rf_interface++;
 
-		/* skip rf extension parameters */
+		/* skip rf extension parameters, bounded by the packet */
 		rf_extension_cnt = *supported_rf_interface++;
+		if (rf_extension_cnt > end - supported_rf_interface)
+			return NCI_STATUS_SYNTAX_ERROR;
 		supported_rf_interface += rf_extension_cnt;
 	}
 

gemini-3.1-pro-preview

null

null

							input: 2642
							output: 33
							thoughts: 164
						

**Analyzing a Patch for NFC Safety**

Okay, so I've got a patch here that's poking at `net/nfc/nci/rsp.c`. Seems like they're adding some crucial length checks to the `nci_core_init_rsp_packet_v1` and `nci_core_init_rsp_packet_v2` functions. Smart move. This is exactly the kind of proactive measure we need to prevent those nasty out-of-bounds read vulnerabilities when parsing NCI core init responses. It's a functional fix, addressing potential memory safety issues. This is exactly the kind of thing that makes me go, "Yep, that needs fuzzing immediately."

Time to get into this a bit deeper. Let's see... the focus here is definitely on those two functions: `nci_core_init_rsp_packet_v1` and `nci_core_init_rsp_packet_v2`. Now, let's identify relevant configs. I'm going to jump into `net/nfc/nci/rsp.c` directly and start digging around the Kconfig to see what we're looking at here. This looks like a solid contribution. Let's get to work.

no matches

{
  "Expression": "config NCI",
  "PathPrefix": "net/nfc/nci/Kconfig"
}

{
  "error": "no matches"
}

gemini-3.1-pro-preview

null

null

							input: 3119
							output: 25
							thoughts: 12
						

Okay, here's my thought process, as if I were considering this myself, tailored for an expert audience:

**Locating the NCI Kconfig File**

Alright, time to get this Kconfig situation sorted for NCI. My first instinct, as always, is to dive straight into the relevant source tree. I need to figure out where the configuration options for the NCI (NFC Controller Interface) module reside. Given my familiarity with how these systems are typically structured, I'm expecting it to follow a relatively standard pattern.

I'll be looking for a file named something along the lines of `Kconfig.nci` or perhaps `nci/Kconfig`, or something reflecting the naming convention of the specific platform I am working with. The key is to find the central point of control for the NCI-related configuration options. I'll need to check the higher level Kconfig files for includes, likely within the NFC or Connectivity sections, depending on how they've organized that portion of the Kconfig tree. I know from experience that good Kconfig design usually has a clear hierarchy. Time to start navigating the usual suspects in the build system.

{
  "Dir": "net/nfc/nci"
}

{
  "Files": [
    "core.c",
    "data.c",
    "hci.c",
    "lib.c",
    "ntf.c",
    "rsp.c",
    "spi.c",
    "uart.c"
  ],
  "Subdirs": null
}

gemini-3.1-pro-preview

null

null

							input: 3460
							output: 30
							thoughts: 30
						

Okay, here's my interpretation of that thought process, assuming I'm well-versed in kernel development and NFC:

**Missing Configuration and Seeking the Source**

Right, so I'm looking at the `net/nfc/nci` directory and I don't see the usual Kconfig file. That's a bit odd; usually, every major subsystem has its configuration options defined within a Kconfig file. I'll need to figure out where the configuration for this part of the NFC stack actually resides. My intuition is telling me that it might be defined in the parent directory. Let's start with a quick check of `net/nfc/Kconfig`. It's the most logical place to begin looking for the configuration options controlling this aspect of the NFC subsystem. Let's see what's in there.

no matches

{
  "Expression": "config NCI",
  "PathPrefix": "net/nfc/Kconfig"
}

{
  "error": "no matches"
}

gemini-3.1-pro-preview

null

null

							input: 3709
							output: 29
							thoughts: 17
						

Here's my thought process, as if I were considering this myself:

**Investigating NCI Configuration**

Okay, so I need to check the configuration options related to NCI (NFC Controller Interface). Where would I find the relevant settings? My first instinct is to look within the NFC-specific configuration files. The kernel's configuration system is fairly organized, so I'll go straight to `net/nfc/Kconfig`. This seems like the most logical starting point for defining and enabling NCI functionality within the kernel. I expect to find options related to NCI's core features, driver selection, and any necessary dependencies there. Let's see what's inside.

no matches

{
  "Expression": "NCI",
  "PathPrefix": "net/nfc/Kconfig"
}

{
  "error": "no matches"
}

gemini-3.1-pro-preview

null

null

							input: 3913
							output: 29
							thoughts: 11
						

Okay, here's my summary, taking the perspective of someone familiar with embedded systems and Kconfig:

**Debugging the NCI Configuration**

Hmm, hold on a second. I'm trying to configure the NCI (NFC Controller Interface) module, but I seem to be missing something. Where's the configuration file? I can't seem to locate the relevant Kconfig file for the NCI implementation. This is a common situation, it's the critical file for selecting the available features and options of the NCI module during the build process. Without it, I'm essentially blind, unable to tailor the NCI's behavior to the specific hardware platform or application requirements. I need to find that Kconfig file so I can set the desired parameters and proceed with the build. Now I just need to find it and figure out where the build system expects it.

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

{
  "Output": "net/nfc/Makefile=6=obj-$(CONFIG_NFC) += nfc.o\nnet/nfc/Makefile:7:obj-$(CONFIG_NFC_NCI) += nci/\nnet/nfc/Makefile-8-obj-$(CONFIG_NFC_HCI) += hci/\n"
}

gemini-3.1-pro-preview

null

null

							input: 4219
							output: 25
							thoughts: 20
						

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

**Tracing Down CONFIG_NFC_NCI**

Okay, so `CONFIG_NFC_NCI`. That's the key. I need to figure out where that's defined in the build system. Is it in a Kconfig file? A Makefile? Some obscure autoconf script? I'll probably start with a `grep` through the relevant kernel source directories. I'll need to remember where NFC is usually located within the tree. It's likely within a subdirectory of drivers/, maybe drivers/nfc/ or drivers/net/nfc/, or perhaps even architecture-specific configs if it's dependent on a particular platform. I'll also check if there's any include file that might be relevant. My aim here is to locate the exact Kconfig symbol definition, so I know how the feature is configured and what dependencies it might have. This also tells me what other configurations relate to NFC-NCI. With that knowledge, I can figure out why the user is asking about it and determine a solution. I'll search for things like `config NFC_NCI`, `depends on NFC`, etc., to get a clear picture.

{
  "Expression": "config NFC_NCI",
  "PathPrefix": ""
}

{
  "Output": "net/nfc/nci/Kconfig-1-# SPDX-License-Identifier: GPL-2.0-only\nnet/nfc/nci/Kconfig:2:config NFC_NCI\nnet/nfc/nci/Kconfig-3-\tdepends on NFC\n--\nnet/nfc/nci/Kconfig-12-\nnet/nfc/nci/Kconfig:13:config NFC_NCI_SPI\nnet/nfc/nci/Kconfig-14-\tdepends on NFC_NCI \u0026\u0026 SPI\n--\nnet/nfc/nci/Kconfig-23-\nnet/nfc/nci/Kconfig:24:config NFC_NCI_UART\nnet/nfc/nci/Kconfig-25-\tdepends on NFC_NCI \u0026\u0026 TTY\n"
}

gemini-3.1-pro-preview

null

null

							input: 4728
							output: 32
							thoughts: 67
						

**Debugging a Potential Configuration Issue**

Okay, so I think I've made a typo somewhere in the path. It looks like the relevant configuration is related to `NFC_NCI`. I'm going to start by confirming that assumption and quickly scanning for any other potential configuration files that might be relevant to this area. Next, I need to understand what's been changed. The patch seems to be modifying `net/nfc/nci/rsp.c`. That tells me the likely area I should be looking at. Just to be thorough and because it's good practice, let me also check the `net/nfc/nci/Makefile`. That will give me a broader understanding of the build process and any potential dependencies or build flags that might be influencing this module.

{
  "Expression": "rsp.o",
  "PathPrefix": "net/nfc/nci/Makefile"
}

{
  "Output": "net/nfc/nci/Makefile=6=obj-$(CONFIG_NFC_NCI) += nci.o\nnet/nfc/nci/Makefile-7-\nnet/nfc/nci/Makefile:8:nci-objs := core.o data.o lib.o ntf.o rsp.o hci.o\nnet/nfc/nci/Makefile-9-\n"
}

gemini-3.1-pro-preview

null

null

							input: 5095
							output: 44
							thoughts: 104
						

**NFC Configuration and Core Initialization**

Okay, so I'm taking a look at this NFC configuration. It seems like setting `CONFIG_NFC_NCI` should be the only config needed, right? But hold on a second... isn't `NFC_NCI` dependent on the base `NFC` feature? Right, so actually, setting `NFC_NCI` should implicitly enable `NFC`. That's good; it simplifies things. I should be able to just list the `NFC_NCI` features.

Now, I need to check some specific symbols related to the initialization of the NCI core. Specifically, I need to verify what versions are supported for the core initialization response packet. The key symbols I have in mind are `nci_core_init_rsp_packet_v1` and `nci_core_init_rsp_packet_v2`.

Let me quickly confirm that these functions are actually defined where they should be, in `net/nfc/nci/rsp.c`. I have a hunch, but verifying is always best practice.

{
  "Expression": "nci_core_init_rsp_packet_v1",
  "PathPrefix": "net/nfc/nci/rsp.c"
}

{
  "Output": "net/nfc/nci/rsp.c=28=static void nci_core_reset_rsp_packet(struct nci_dev *ndev,\n--\nnet/nfc/nci/rsp.c-46-\nnet/nfc/nci/rsp.c:47:static u8 nci_core_init_rsp_packet_v1(struct nci_dev *ndev,\nnet/nfc/nci/rsp.c-48-\t\t\t\t      const struct sk_buff *skb)\n--\nnet/nfc/nci/rsp.c=146=static void nci_core_init_rsp_packet(struct nci_dev *ndev, const struct sk_buff *skb)\n--\nnet/nfc/nci/rsp.c-150-\tif (!(ndev-\u003enci_ver \u0026 NCI_VER_2_MASK))\nnet/nfc/nci/rsp.c:151:\t\tstatus = nci_core_init_rsp_packet_v1(ndev, skb);\nnet/nfc/nci/rsp.c-152-\telse\n"
}

gemini-3.1-pro-preview

null

null

							input: 5764
							output: 26
							thoughts: 181
						

**My Assessment of the NCI Core Init Response Patch**

Okay, so this patch directly addresses a critical issue: missing length checks in how we parse NCI core initialization responses. My immediate thought is, yes, absolutely, this is a memory safety fix. It's a functional change, preventing potential out-of-bounds reads during the response parsing, which is precisely the kind of vulnerability we want to squash. `WorthFuzzing`? Absolutely. This is a prime target.

My investigation of the configs required for reproducing the issue or verifying the fix indicates that `NFC_NCI` is the primary, perhaps only, relevant configuration. However, I need to be thorough. I'm going to quickly check for any related configurations. Maybe `NFC_VIRTUAL_NCI` in particular? I'll probably look into `drivers/nfc/virtual_ncidev.c` or a similar file to confirm there aren't any other configs I need to be aware of. The `FocusSymbols` are pretty straightforward: we're focusing on `nci_core_init_rsp_packet_v1` and `nci_core_init_rsp_packet_v2`, so that's where I need to look.

{
  "Expression": "NFC_VIRTUAL",
  "PathPrefix": ""
}

{
  "Output": "drivers/nfc/Kconfig=42=config NFC_PORT100\n--\ndrivers/nfc/Kconfig-51-\ndrivers/nfc/Kconfig:52:config NFC_VIRTUAL_NCI\ndrivers/nfc/Kconfig-53-\ttristate \"NCI device simulator driver\"\n--\ndrivers/nfc/Makefile=19=obj-$(CONFIG_NFC_ST95HF)\t+= st95hf/\ndrivers/nfc/Makefile:20:obj-$(CONFIG_NFC_VIRTUAL_NCI)\t+= virtual_ncidev.o\n--\ntools/testing/selftests/nci/config=2=CONFIG_NFC_NCI=y\ntools/testing/selftests/nci/config:3:CONFIG_NFC_VIRTUAL_NCI=y\n"
}

gemini-3.1-pro-preview

null

null

							input: 6447
							output: 114
							thoughts: 47
						

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

**Thinking Through Virtual NCI for Fuzzing**

Right, `NFC_VIRTUAL_NCI`. That's the simulator driver, isn't it? Classic! Super handy for fuzzing the NCI stack. No need to worry about real hardware at this stage, which is precisely the beauty of it. Gets me up and running fast. I'd be remiss not to include that when I'm setting up my fuzzing environment. Saves time and allows me to iterate on the inputs much faster.

{
  "EnableConfigs": [
    "NFC_NCI",
    "NFC_VIRTUAL_NCI"
  ],
  "FocusSymbols": [
    "nci_core_init_rsp_packet_v1",
    "nci_core_init_rsp_packet_v2"
  ],
  "Reasoning": "The patch adds length checks to NCI core init response packets parsing to prevent out-of-bounds reads. This is a functional change fixing potential memory safety issues.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "NFC_NCI",
    "NFC_VIRTUAL_NCI"
  ],
  "FocusSymbols": [
    "nci_core_init_rsp_packet_v1",
    "nci_core_init_rsp_packet_v2"
  ],
  "Reasoning": "The patch adds length checks to NCI core init response packets parsing to prevent out-of-bounds reads. This is a functional change fixing potential memory safety issues.",
  "WorthFuzzing": true
}