AI Trajectory

null

{
  "EnableConfigs": [
    "NFC"
  ],
  "FocusSymbols": [
    "llcp_raw_sock_bind"
  ],
  "Reasoning": "The patch fixes a potential memory leak or use-after-free in the `llcp_raw_sock_bind` function by properly releasing the old `local` reference before assigning a new one. This is a functional change in reachable core networking code.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit c4abb68dd54a95cfdb00f910737a46fd50fad6ab\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Mon Jul 13 02:04:49 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 feab29fc62f44b..0c00cdaabbc611 100644\n--- a/net/nfc/llcp_sock.c\n+++ b/net/nfc/llcp_sock.c\n@@ -152,6 +152,7 @@ static int llcp_raw_sock_bind(struct socket *sock, struct sockaddr_unsized *addr\n \tstruct sock *sk = sock-\u003esk;\n \tstruct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);\n \tstruct nfc_llcp_local *local;\n+\tstruct nfc_llcp_local *old_local;\n \tstruct nfc_dev *dev;\n \tstruct sockaddr_nfc_llcp llcp_addr;\n \tint len, ret = 0;\n@@ -185,6 +186,11 @@ static int llcp_raw_sock_bind(struct socket *sock, struct sockaddr_unsized *addr\n \t\tgoto put_dev;\n \t}\n \n+\told_local = llcp_sock-\u003elocal;\n+\tllcp_sock-\u003elocal = NULL;\n+\tllcp_sock-\u003edev = NULL;\n+\tnfc_llcp_local_put(old_local);\n+\n \tllcp_sock-\u003edev = dev;\n \tllcp_sock-\u003elocal = local;\n \tllcp_sock-\u003enfc_protocol = llcp_addr.nfc_protocol;\n"
}

gemini-3.1-pro-preview

null

{
  "EnableConfigs": [
    "NFC"
  ],
  "FocusSymbols": [
    "llcp_raw_sock_bind"
  ],
  "Reasoning": "The patch fixes a potential memory leak or use-after-free in the `llcp_raw_sock_bind` function by properly releasing the old `local` reference before assigning a new one. This is a functional change in reachable core networking code.",
  "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 c4abb68dd54a95cfdb00f910737a46fd50fad6ab
Author: syz-cluster <triage@syzkaller.com>
Date:   Mon Jul 13 02:04:49 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c
index feab29fc62f44b..0c00cdaabbc611 100644
--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -152,6 +152,7 @@ static int llcp_raw_sock_bind(struct socket *sock, struct sockaddr_unsized *addr
 	struct sock *sk = sock->sk;
 	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
 	struct nfc_llcp_local *local;
+	struct nfc_llcp_local *old_local;
 	struct nfc_dev *dev;
 	struct sockaddr_nfc_llcp llcp_addr;
 	int len, ret = 0;
@@ -185,6 +186,11 @@ static int llcp_raw_sock_bind(struct socket *sock, struct sockaddr_unsized *addr
 		goto put_dev;
 	}
 
+	old_local = llcp_sock->local;
+	llcp_sock->local = NULL;
+	llcp_sock->dev = NULL;
+	nfc_llcp_local_put(old_local);
+
 	llcp_sock->dev = dev;
 	llcp_sock->local = local;
 	llcp_sock->nfc_protocol = llcp_addr.nfc_protocol;

gemini-3.1-pro-preview

null

null

							input: 2012
							output: 39
							thoughts: 191
						

**Analyzing a NFC LLCP Socket Patch**

Okay, so I've got this patch here that's touching `net/nfc/llcp_sock.c`. Seems like the change is in the `llcp_raw_sock_bind` function. Reading the code, it looks like they're adding a few lines:

```c
	old_local = llcp_sock->local;
	llcp_sock->local = NULL;
	llcp_sock->dev = NULL;
	nfc_llcp_local_put(old_local);
```

Right, this is a pretty straightforward functional change. Immediately, I see the purpose: they're cleaning up the old `llcp_sock->local` before assigning a new one. This is good; it's preventing a potential memory leak or a use-after-free scenario. This is a common and often overlooked issue, especially in networking code with complex object management.

Now, let's just make sure it's correct. I want to take a closer look at the surrounding code in `llcp_raw_sock_bind` itself and the related functions. I'll use `grepper` to quickly locate the function within the `net/nfc/llcp_sock.c` file and understand the context better. I want to make sure this change doesn't introduce any regressions or unintended consequences in the binding process. I'll need to check how `llcp_sock->local` and `llcp_sock->dev` are used after the `bind` to ensure the clean up doesn't break anything.

{
  "Expression": "llcp_raw_sock_bind",
  "PathPrefix": "net/nfc/llcp_sock.c"
}

{
  "Output": "net/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-148-\nnet/nfc/llcp_sock.c:149:static int llcp_raw_sock_bind(struct socket *sock, struct sockaddr_unsized *addr,\nnet/nfc/llcp_sock.c-150-\t\t\t      int alen)\n--\nnet/nfc/llcp_sock.c=945=static const struct proto_ops llcp_rawsock_ops = {\n--\nnet/nfc/llcp_sock.c-947-\t.owner          = THIS_MODULE,\nnet/nfc/llcp_sock.c:948:\t.bind           = llcp_raw_sock_bind,\nnet/nfc/llcp_sock.c-949-\t.connect        = sock_no_connect,\n"
}

gemini-3.1-pro-preview

null

null

							input: 2844
							output: 30
							thoughts: 61
						

**Analyzing the LLCP Raw Socket Binding**

Okay, so I'm looking at `llcp_raw_sock_bind` and it's pretty clear this is the `bind` function for the `llcp_rawsock_ops` structure. Makes perfect sense. This means, as I suspected, this function is the entry point for handling the `bind()` system call when a user-space application attempts to bind a raw NFC LLCP socket. Seems straightforward so far. Now, just to be absolutely sure, I should double check the relevant Kconfig options for NFC LLCP support to confirm that this path is actually enabled and reachable in the kernel's configuration. Gotta be meticulous.

no matches

{
  "Expression": "config NFC_LLCP",
  "PathPrefix": "net/nfc/"
}

{
  "error": "no matches"
}

gemini-3.1-pro-preview

null

null

							input: 3093
							output: 27
							thoughts: 9
						

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

**Investigating NFC Configuration**

Alright, time to get down to brass tacks. I need to make sure the NFC support is configured correctly, or at least understand what options are available and how they're set up. My immediate instinct is to dive into the Kconfig files. This is where the core configuration decisions are made, and it's where I'll find the dependencies, defaults, and potential configuration options related to NFC. I'll need to remember the typical naming conventions and how the project structures its config files so I can quickly identify the relevant section. I'll be looking for things like device drivers, protocol support, and any platform-specific configurations related to NFC controllers or secure elements. Knowing this, I can start to understand the complete picture of how NFC is configured within the existing system.

{
  "Expression": "config NFC",
  "PathPrefix": "net/nfc/"
}

{
  "Output": "net/nfc/Kconfig-5-\nnet/nfc/Kconfig:6:menuconfig NFC\nnet/nfc/Kconfig-7-\tdepends on RFKILL || !RFKILL\n--\nnet/nfc/Kconfig-16-\nnet/nfc/Kconfig:17:config NFC_DIGITAL\nnet/nfc/Kconfig-18-\tdepends on NFC\n--\nnet/nfc/hci/Kconfig-1-# SPDX-License-Identifier: GPL-2.0-only\nnet/nfc/hci/Kconfig:2:config NFC_HCI\nnet/nfc/hci/Kconfig-3-\tdepends on NFC\n--\nnet/nfc/hci/Kconfig-10-\nnet/nfc/hci/Kconfig:11:config NFC_SHDLC\nnet/nfc/hci/Kconfig-12-\tdepends on NFC_HCI\n--\nnet/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: 3730
							output: 31
							thoughts: 33
						

Okay, here's my interpretation of those thoughts, presented as a first-person expert summary:

**Analyzing NFC Configuration Requirements**

Alright, the core configuration in question is `NFC`. My initial focus is on `net/nfc/llcp_sock.c`. I need to quickly determine if `NFC` is *all* that's required for this particular module, or if there are any other supporting configurations or dependencies I need to be aware of within the current build environment. I need to ensure a complete and correct build. It's about efficiency; I can't afford to waste time chasing down build errors later due to a missing or misconfigured option. My deep understanding of this networking subsystem informs the necessity to carefully examine this `llcp_sock.c` specifically.

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

{
  "Output": "net/nfc/Makefile=11=nfc-objs := core.o netlink.o af_nfc.o rawsock.o llcp_core.o llcp_commands.o \\\nnet/nfc/Makefile:12:\t\tllcp_sock.o\nnet/nfc/Makefile-13-\n--\nnet/nfc/llcp_sock.c=836=static int llcp_sock_recvmsg(struct socket *sock, struct msghdr *msg,\n--\nnet/nfc/llcp_sock.c-924-\nnet/nfc/llcp_sock.c:925:static const struct proto_ops llcp_sock_ops = {\nnet/nfc/llcp_sock.c-926-\t.family         = PF_NFC,\n--\nnet/nfc/llcp_sock.c=1032=static int llcp_sock_create(struct net *net, struct socket *sock,\n--\nnet/nfc/llcp_sock.c-1048-\t} else {\nnet/nfc/llcp_sock.c:1049:\t\tsock-\u003eops = \u0026llcp_sock_ops;\nnet/nfc/llcp_sock.c-1050-\t}\n"
}

gemini-3.1-pro-preview

null

null

							input: 4280
							output: 32
							thoughts: 41
						

Okay, here's my interpretation of those thoughts, presented as a personal thought process, as requested:

**NFC Object Compilation Path**

Alright, so the question is *when* is the object for this NFC functionality compiled? Ah, right, it looks like it gets built with the `nfc-objs`. That's the key. So, the implication here is that `nfc-objs`' compilation is the triggering event. But when is *that* compiled? Ah, that's when `CONFIG_NFC` is defined. Okay, good. That makes sense from a conditional compilation standpoint. I’m pretty confident that is correct, but hold on a moment… let me just double-check that by taking a quick look at the `net/nfc/Makefile` to be absolutely certain. Just a quick sanity check to avoid any assumptions. Good, good, better safe than sorry.

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

{
  "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"
}

gemini-3.1-pro-preview

null

null

							input: 4777
							output: 39
							thoughts: 94
						

Okay, here's my breakdown of this.

**Focusing on the NFC Configuration and Binding Function**

Right, so it looks like `CONFIG_NFC` is the sole configuration item of interest here. That simplifies things immensely; at least we don't need to chase down a nest of related configs. Now, where's the real action? Ah, it appears we're zeroing in on `llcp_raw_sock_bind`. That's the function the patch is targeting, and that's precisely where I need to focus my attention.

I suppose I should glance around for a minute to ensure that nothing else might need attention. There is `llcp_sock_bind` too, but the commit message *explicitly* mentions changes to `llcp_raw_sock_bind`, so that's the primary target.

Time to dive into the code. I'll need to check the definition of `llcp_raw_sock_bind`, which, as I recall, should be located in `net/nfc/llcp_sock.c`. Let's see what's changed and figure out the implications.

{
  "File": "net/nfc/llcp_sock.c",
  "FirstLine": 148,
  "LineCount": 50
}

{
  "Contents": " 148:\t\n 149:\tstatic int llcp_raw_sock_bind(struct socket *sock, struct sockaddr_unsized *addr,\n 150:\t\t\t\t      int alen)\n 151:\t{\n 152:\t\tstruct sock *sk = sock-\u003esk;\n 153:\t\tstruct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);\n 154:\t\tstruct nfc_llcp_local *local;\n 155:\t\tstruct nfc_llcp_local *old_local;\n 156:\t\tstruct nfc_dev *dev;\n 157:\t\tstruct sockaddr_nfc_llcp llcp_addr;\n 158:\t\tint len, ret = 0;\n 159:\t\n 160:\t\tif (!addr || alen \u003c offsetofend(struct sockaddr, sa_family) ||\n 161:\t\t    addr-\u003esa_family != AF_NFC)\n 162:\t\t\treturn -EINVAL;\n 163:\t\n 164:\t\tpr_debug(\"sk %p addr %p family %d\\n\", sk, addr, addr-\u003esa_family);\n 165:\t\n 166:\t\tmemset(\u0026llcp_addr, 0, sizeof(llcp_addr));\n 167:\t\tlen = min_t(unsigned int, sizeof(llcp_addr), alen);\n 168:\t\tmemcpy(\u0026llcp_addr, addr, len);\n 169:\t\n 170:\t\tlock_sock(sk);\n 171:\t\n 172:\t\tif (sk-\u003esk_state != LLCP_CLOSED) {\n 173:\t\t\tret = -EBADFD;\n 174:\t\t\tgoto error;\n 175:\t\t}\n 176:\t\n 177:\t\tdev = nfc_get_device(llcp_addr.dev_idx);\n 178:\t\tif (dev == NULL) {\n 179:\t\t\tret = -ENODEV;\n 180:\t\t\tgoto error;\n 181:\t\t}\n 182:\t\n 183:\t\tlocal = nfc_llcp_find_local(dev);\n 184:\t\tif (local == NULL) {\n 185:\t\t\tret = -ENODEV;\n 186:\t\t\tgoto put_dev;\n 187:\t\t}\n 188:\t\n 189:\t\told_local = llcp_sock-\u003elocal;\n 190:\t\tllcp_sock-\u003elocal = NULL;\n 191:\t\tllcp_sock-\u003edev = NULL;\n 192:\t\tnfc_llcp_local_put(old_local);\n 193:\t\n 194:\t\tllcp_sock-\u003edev = dev;\n 195:\t\tllcp_sock-\u003elocal = local;\n 196:\t\tllcp_sock-\u003enfc_protocol = llcp_addr.nfc_protocol;\n 197:\t\n"
}

gemini-3.1-pro-preview

null

null

							input: 5920
							output: 97
							thoughts: 112
						

**Analyzing a Key Network Patch**

Okay, so this patch is interesting. It looks like we've got a fix that addresses a potential memory leak or a use-after-free vulnerability within the `llcp_raw_sock_bind` function. Specifically, it seems the issue stems from how the `old_local` reference was handled. By properly releasing that old reference before assigning a new one, this patch is tightening up memory management.

Functionally, this is a definite change, which means we need to treat it with due diligence. Given that this code is in core networking, and seems reachable, it warrants a close look. It's time to fire up the fuzzing tools and really hammer at this area. We need to focus those fuzzing efforts specifically on `llcp_raw_sock_bind`, that's the key symbol here. Given that this is potentially related to NFC functionality, I should probably make sure the `NFC` config is enabled during testing to get maximum coverage. Let's see if we can find any regression bugs here, given that this looks like a functional improvement.

{
  "EnableConfigs": [
    "NFC"
  ],
  "FocusSymbols": [
    "llcp_raw_sock_bind"
  ],
  "Reasoning": "The patch fixes a potential memory leak or use-after-free in the `llcp_raw_sock_bind` function by properly releasing the old `local` reference before assigning a new one. This is a functional change in reachable core networking code.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "NFC"
  ],
  "FocusSymbols": [
    "llcp_raw_sock_bind"
  ],
  "Reasoning": "The patch fixes a potential memory leak or use-after-free in the `llcp_raw_sock_bind` function by properly releasing the old `local` reference before assigning a new one. This is a functional change in reachable core networking code.",
  "WorthFuzzing": true
}