AI Trajectory

null

{
  "EnableConfigs": [
    "NFC_NCI"
  ],
  "FocusSymbols": [
    "nci_rf_discover_ntf_packet",
    "nci_rf_intf_activated_ntf_packet"
  ],
  "Reasoning": "The patch fixes uninitialized memory usage in nci_rf_discover_ntf_packet and nci_rf_intf_activated_ntf_packet by initializing the ntf structs to zero. This is a functional change in the NFC NCI layer that should be fuzzed.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit 22fb87ace671a7e8df1dcf76211743dcceac234e\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Fri Jun 26 09:58:24 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/nfc/nci/ntf.c b/net/nfc/nci/ntf.c\nindex c96512bb865315..274d9a4202c9db 100644\n--- a/net/nfc/nci/ntf.c\n+++ b/net/nfc/nci/ntf.c\n@@ -440,7 +440,7 @@ void nci_clear_target_list(struct nci_dev *ndev)\n static int nci_rf_discover_ntf_packet(struct nci_dev *ndev,\n \t\t\t\t      const struct sk_buff *skb)\n {\n-\tstruct nci_rf_discover_ntf ntf;\n+\tstruct nci_rf_discover_ntf ntf = {};\n \tconst __u8 *data;\n \tbool add_target = true;\n \n@@ -688,7 +688,7 @@ static int nci_rf_intf_activated_ntf_packet(struct nci_dev *ndev,\n \t\t\t\t\t    const struct sk_buff *skb)\n {\n \tstruct nci_conn_info *conn_info;\n-\tstruct nci_rf_intf_activated_ntf ntf;\n+\tstruct nci_rf_intf_activated_ntf ntf = {};\n \tconst __u8 *data;\n \tint err = NCI_STATUS_OK;\n \n"
}

gemini-3.1-pro-preview

null

{
  "EnableConfigs": [
    "NFC_NCI"
  ],
  "FocusSymbols": [
    "nci_rf_discover_ntf_packet",
    "nci_rf_intf_activated_ntf_packet"
  ],
  "Reasoning": "The patch fixes uninitialized memory usage in nci_rf_discover_ntf_packet and nci_rf_intf_activated_ntf_packet by initializing the ntf structs to zero. This is a functional change in the NFC NCI layer that should be fuzzed.",
  "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 22fb87ace671a7e8df1dcf76211743dcceac234e
Author: syz-cluster <triage@syzkaller.com>
Date:   Fri Jun 26 09:58:24 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/nfc/nci/ntf.c b/net/nfc/nci/ntf.c
index c96512bb865315..274d9a4202c9db 100644
--- a/net/nfc/nci/ntf.c
+++ b/net/nfc/nci/ntf.c
@@ -440,7 +440,7 @@ void nci_clear_target_list(struct nci_dev *ndev)
 static int nci_rf_discover_ntf_packet(struct nci_dev *ndev,
 				      const struct sk_buff *skb)
 {
-	struct nci_rf_discover_ntf ntf;
+	struct nci_rf_discover_ntf ntf = {};
 	const __u8 *data;
 	bool add_target = true;
 
@@ -688,7 +688,7 @@ static int nci_rf_intf_activated_ntf_packet(struct nci_dev *ndev,
 					    const struct sk_buff *skb)
 {
 	struct nci_conn_info *conn_info;
-	struct nci_rf_intf_activated_ntf ntf;
+	struct nci_rf_intf_activated_ntf ntf = {};
 	const __u8 *data;
 	int err = NCI_STATUS_OK;
 

gemini-3.1-pro-preview

null

null

							input: 1983
							output: 89
							thoughts: 143
						

**Analyzing a Recent NFC Patch**

Okay, so I've been looking at this patch that touches `net/nfc/nci/ntf.c`. Right away, I see that they're initializing two structs: `nci_rf_discover_ntf ntf = {};` and `nci_rf_intf_activated_ntf ntf = {};` to zero. It's a subtle but important change – a functional fix to prevent the possibility of uninitialized memory being used, which can always lead to nasty surprises down the line.

Now, my expert instinct tells me it's time to dig into the details. I need to understand how these structs are *used* in that file. So, I'm going to take a closer look at `net/nfc/nci/ntf.c` itself, and particularly the `nci_rf_discover_ntf_packet` and `nci_rf_intf_activated_ntf_packet` functions. Those are the key areas where these structs are likely being populated and potentially transmitted.

To speed things up, I think I'll use `grepper`. I'll run a quick search there to grab the function definitions and any relevant configuration or usage data. This way, I can quickly get a holistic understanding of how this patch impacts the NFC stack. This should provide the information needed to evaluate the significance of this initialization change.

{
  "Expression": "nci_rf_discover_ntf_packet",
  "PathPrefix": "net/nfc/nci/ntf.c"
}

{
  "Output": "net/nfc/nci/ntf.c=432=void nci_clear_target_list(struct nci_dev *ndev)\n--\nnet/nfc/nci/ntf.c-439-\nnet/nfc/nci/ntf.c:440:static int nci_rf_discover_ntf_packet(struct nci_dev *ndev,\nnet/nfc/nci/ntf.c-441-\t\t\t\t      const struct sk_buff *skb)\n--\nnet/nfc/nci/ntf.c=966=void nci_ntf_packet(struct nci_dev *ndev, struct sk_buff *skb)\n--\nnet/nfc/nci/ntf.c-1009-\tcase NCI_OP_RF_DISCOVER_NTF:\nnet/nfc/nci/ntf.c:1010:\t\tif (nci_rf_discover_ntf_packet(ndev, skb))\nnet/nfc/nci/ntf.c-1011-\t\t\tgoto end;\n"
}

{
  "Expression": "nci_rf_intf_activated_ntf_packet",
  "PathPrefix": "net/nfc/nci/ntf.c"
}

{
  "Output": "net/nfc/nci/ntf.c=665=static int nci_store_ats_nfc_iso_dep(struct nci_dev *ndev,\n--\nnet/nfc/nci/ntf.c-686-\nnet/nfc/nci/ntf.c:687:static int nci_rf_intf_activated_ntf_packet(struct nci_dev *ndev,\nnet/nfc/nci/ntf.c-688-\t\t\t\t\t    const struct sk_buff *skb)\n--\nnet/nfc/nci/ntf.c=966=void nci_ntf_packet(struct nci_dev *ndev, struct sk_buff *skb)\n--\nnet/nfc/nci/ntf.c-1014-\tcase NCI_OP_RF_INTF_ACTIVATED_NTF:\nnet/nfc/nci/ntf.c:1015:\t\tif (nci_rf_intf_activated_ntf_packet(ndev, skb))\nnet/nfc/nci/ntf.c-1016-\t\t\tgoto end;\n"
}

gemini-3.1-pro-preview

null

null

							input: 3099
							output: 31
							thoughts: 22
						

Here's my thought process, summarized as you requested:

**Kconfig Dive for NFC NTF Configuration**

Okay, time to dig into the Kconfig system. Specifically, I need to check the configuration options related to the `net/nfc/nci/ntf.c` file. I'm going to start by navigating to the relevant `Kconfig` files and trace any dependencies or relevant symbols that affect the build process for this particular NTF (NFC Transmit Frame) module. I need to understand what defines are active and what conditions, like specific hardware or driver selection, control the inclusion of this code. Knowing this is crucial for understanding how features are enabled and disabled, and how they might interact with other NFC-related components in the system. I'm looking for the breadcrumbs that will reveal the exact conditions that determine if this component is built, included, and functional within the broader NFC subsystem. I'll pay close attention to any default values, help texts, and menu structure to build a holistic picture of the configuration options.

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

{
  "Output": "net/nfc/nci/Makefile-2-#\nnet/nfc/nci/Makefile:3:# Makefile for the Linux NFC NCI layer.\nnet/nfc/nci/Makefile-4-#\nnet/nfc/nci/Makefile-5-\nnet/nfc/nci/Makefile:6:obj-$(CONFIG_NFC_NCI) += nci.o\nnet/nfc/nci/Makefile-7-\n--\nnet/nfc/nci/Makefile=10=nci_spi-y += spi.o\nnet/nfc/nci/Makefile:11:obj-$(CONFIG_NFC_NCI_SPI) += nci_spi.o\nnet/nfc/nci/Makefile-12-\nnet/nfc/nci/Makefile=13=nci_uart-y += uart.o\nnet/nfc/nci/Makefile:14:obj-$(CONFIG_NFC_NCI_UART) += nci_uart.o\n"
}

gemini-3.1-pro-preview

null

null

							input: 3618
							output: 129
							thoughts: 105
						

**My Assessment of the NFC Driver Vulnerability**

Okay, so I've pinpointed the relevant configuration option: it's `CONFIG_NFC_NCI`. The key here is this patch. It addresses uninitialized memory usage within the `nci_rf_discover_ntf_packet` and `nci_rf_intf_activated_ntf_packet` functions. My immediate thought is, "This is absolutely a prime target for fuzzing." The fact that memory is uninitialized is a classic recipe for exploitation. I'll need to focus my efforts on those two specific functions – `nci_rf_discover_ntf_packet` and `nci_rf_intf_activated_ntf_packet` – they are my focus symbols. My attack vector will definitely involve enabling `NFC_NCI` within the kernel configuration. I'll need to ensure this config is enabled to reproduce the issue.

{
  "EnableConfigs": [
    "NFC_NCI"
  ],
  "FocusSymbols": [
    "nci_rf_discover_ntf_packet",
    "nci_rf_intf_activated_ntf_packet"
  ],
  "Reasoning": "The patch fixes uninitialized memory usage in nci_rf_discover_ntf_packet and nci_rf_intf_activated_ntf_packet by initializing the ntf structs to zero. This is a functional change in the NFC NCI layer that should be fuzzed.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "NFC_NCI"
  ],
  "FocusSymbols": [
    "nci_rf_discover_ntf_packet",
    "nci_rf_intf_activated_ntf_packet"
  ],
  "Reasoning": "The patch fixes uninitialized memory usage in nci_rf_discover_ntf_packet and nci_rf_intf_activated_ntf_packet by initializing the ntf structs to zero. This is a functional change in the NFC NCI layer that should be fuzzed.",
  "WorthFuzzing": true
}