AI Trajectory

null

{
  "EnableConfigs": [
    "NF_CONNTRACK",
    "NF_CT_PROTO_SCTP"
  ],
  "FocusSymbols": [
    "nf_conntrack_sctp_packet"
  ],
  "Reasoning": "The patch modifies the SCTP connection tracking logic in netfilter, specifically handling of SCTP_CID_COOKIE_ACK, SCTP_CID_ERROR, SCTP_CID_SHUTDOWN, and SCTP_CID_SHUTDOWN_ACK chunks. This is reachable core kernel logic and should be fuzzed.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit d7c05cebcc50dc8c0b169d83fd9b863f3fb3f9f2\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Sat Aug 1 23:13:43 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c\nindex 7e10fa65cbdd3..9978ecd05b1e8 100644\n--- a/net/netfilter/nf_conntrack_proto_sctp.c\n+++ b/net/netfilter/nf_conntrack_proto_sctp.c\n@@ -407,9 +407,17 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,\n \t\t\t/* (D) vtag must be same as init_vtag as found in INIT_ACK */\n \t\t\tif (sh-\u003evtag != ct-\u003eproto.sctp.vtag[dir])\n \t\t\t\tgoto out_unlock;\n-\t\t} else if (sch-\u003etype == SCTP_CID_COOKIE_ACK) {\n-\t\t\tct-\u003eproto.sctp.init[dir] = 0;\n-\t\t\tct-\u003eproto.sctp.init[!dir] = 0;\n+\t\t} else if (sch-\u003etype == SCTP_CID_COOKIE_ACK ||\n+\t\t\t   sch-\u003etype == SCTP_CID_ERROR ||\n+\t\t\t   sch-\u003etype == SCTP_CID_SHUTDOWN ||\n+\t\t\t   sch-\u003etype == SCTP_CID_SHUTDOWN_ACK) {\n+\t\t\tif (ct-\u003eproto.sctp.vtag[dir] \u0026\u0026\n+\t\t\t    sh-\u003evtag != ct-\u003eproto.sctp.vtag[dir])\n+\t\t\t\tgoto out_unlock;\n+\t\t\tif (sch-\u003etype == SCTP_CID_COOKIE_ACK) {\n+\t\t\t\tct-\u003eproto.sctp.init[dir] = 0;\n+\t\t\t\tct-\u003eproto.sctp.init[!dir] = 0;\n+\t\t\t}\n \t\t} else if (sch-\u003etype == SCTP_CID_HEARTBEAT) {\n \t\t\tif (ct-\u003eproto.sctp.vtag[dir] == 0) {\n \t\t\t\tpr_debug(\"Setting %d vtag %x for dir %d\\n\", sch-\u003etype, sh-\u003evtag, dir);\n"
}

best-expensive

null

{
  "EnableConfigs": [
    "NF_CONNTRACK",
    "NF_CT_PROTO_SCTP"
  ],
  "FocusSymbols": [
    "nf_conntrack_sctp_packet"
  ],
  "Reasoning": "The patch modifies the SCTP connection tracking logic in netfilter, specifically handling of SCTP_CID_COOKIE_ACK, SCTP_CID_ERROR, SCTP_CID_SHUTDOWN, and SCTP_CID_SHUTDOWN_ACK chunks. This is reachable core kernel logic and 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).
- Code in vendor-specific PCIe switch, SmartNIC, or GPU drivers (e.g., mlxsw, pds_core, qed,
  ionic, amdgpu) that require physical PCIe hardware cards not emulated in standard QEMU.
- Driver .remove, .shutdown, or pci_unregister_driver teardown callbacks (e.g., igb_remove)
  that are executed only during PCI hot-unplug or sysfs driver unbind operations.

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.
   Prefer non-static, non-inlined API entrypoint functions over internal static helper functions
   (which are inlined by the compiler and do not have distinct symbol addresses).
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.
   Also check "depends on" lines in Kconfig to include any non-standard parent subsystem configs
   needed for Kbuild to compile the code statically into vmlinux. 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 d7c05cebcc50dc8c0b169d83fd9b863f3fb3f9f2
Author: syz-cluster <triage@syzkaller.com>
Date:   Sat Aug 1 23:13:43 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c
index 7e10fa65cbdd3..9978ecd05b1e8 100644
--- a/net/netfilter/nf_conntrack_proto_sctp.c
+++ b/net/netfilter/nf_conntrack_proto_sctp.c
@@ -407,9 +407,17 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,
 			/* (D) vtag must be same as init_vtag as found in INIT_ACK */
 			if (sh->vtag != ct->proto.sctp.vtag[dir])
 				goto out_unlock;
-		} else if (sch->type == SCTP_CID_COOKIE_ACK) {
-			ct->proto.sctp.init[dir] = 0;
-			ct->proto.sctp.init[!dir] = 0;
+		} else if (sch->type == SCTP_CID_COOKIE_ACK ||
+			   sch->type == SCTP_CID_ERROR ||
+			   sch->type == SCTP_CID_SHUTDOWN ||
+			   sch->type == SCTP_CID_SHUTDOWN_ACK) {
+			if (ct->proto.sctp.vtag[dir] &&
+			    sh->vtag != ct->proto.sctp.vtag[dir])
+				goto out_unlock;
+			if (sch->type == SCTP_CID_COOKIE_ACK) {
+				ct->proto.sctp.init[dir] = 0;
+				ct->proto.sctp.init[!dir] = 0;
+			}
 		} else if (sch->type == SCTP_CID_HEARTBEAT) {
 			if (ct->proto.sctp.vtag[dir] == 0) {
 				pr_debug("Setting %d vtag %x for dir %d\n", sch->type, sh->vtag, dir);

gemini-3.1-pro-preview

null

null

							input: 2371
							output: 39
							thoughts: 225
						

**Analyzing the SCTP Connection Tracking Patch**

Okay, so this patch is digging into `net/netfilter/nf_conntrack_proto_sctp.c`. Specifically, it's tweaking how we handle certain SCTP chunk types within `nf_conntrack_sctp_packet`: `SCTP_CID_COOKIE_ACK`, `SCTP_CID_ERROR`, `SCTP_CID_SHUTDOWN`, and `SCTP_CID_SHUTDOWN_ACK`. The core of the change seems to be this new check. The code looks correct, but I need to dive deeper.

My immediate thought is, what are the implications of this change on the module itself? I need to check the relevant Kconfig options for `nf_conntrack_proto_sctp.c` to understand any dependencies or required configurations. I'll need to know whether the functionality affected by this patch is likely to be active in any given configuration. Let's see... a quick grep for `nf_conntrack_proto_sctp.o` in the `net/netfilter/Makefile` should get me pointed in the right direction. This is a functional area of the netfilter SCTP connection tracking, and any change needs to be properly vetted.

{
  "Expression": "nf_conntrack_proto_sctp.o",
  "PathPrefix": "net/netfilter/Makefile"
}

{
  "Output": "net/netfilter/Makefile=15=nf_conntrack-$(CONFIG_NF_CONNTRACK_OVS) += nf_conntrack_ovs.o\nnet/netfilter/Makefile:16:nf_conntrack-$(CONFIG_NF_CT_PROTO_SCTP) += nf_conntrack_proto_sctp.o\nnet/netfilter/Makefile-17-nf_conntrack-$(CONFIG_NF_CT_PROTO_GRE) += nf_conntrack_proto_gre.o\n"
}

gemini-3.1-pro-preview

null

null

							input: 3046
							output: 37
							thoughts: 108
						

**Analyzing SCTP Connection Tracking in the Kernel**

Okay, so I'm looking at this and my immediate thought is, "it depends on `CONFIG_NF_CT_PROTO_SCTP`." But hold on, let's not jump to conclusions. Is that config even *relevant* anymore? I need to verify whether `CONFIG_NF_CT_PROTO_SCTP` is a standalone option, or if it's implicitly built-in when `CONFIG_NF_CONNTRACK` is enabled. My understanding is that the kernel's changed over time, especially with SCTP conntrack, which might be baked in now.

Right, time for a more targeted investigation. Let's fire up a grep on `NF_CT_PROTO_SCTP` in the `net/netfilter/Kconfig` file. That should give me a definitive answer on how it's handled in the current (or at least recent) kernel versions. Need to know the architecture before I make any decisions based on the kernel build config.

{
  "Expression": "config NF_CT_PROTO_SCTP",
  "PathPrefix": "net/netfilter/Kconfig"
}

{
  "Output": "net/netfilter/Kconfig=198=config NF_CT_PROTO_GRE\n--\nnet/netfilter/Kconfig-200-\nnet/netfilter/Kconfig:201:config NF_CT_PROTO_SCTP\nnet/netfilter/Kconfig-202-\tbool 'SCTP protocol connection tracking support'\n"
}

gemini-3.1-pro-preview

null

null

							input: 3507
							output: 72
							thoughts: 25
						

Here's my summary, as though I were thinking through the process:

**Diving into the Configuration**

Alright, this is a legitimate configuration option – `NF_CT_PROTO_SCTP`. My immediate instinct is to understand its place within the broader system. I need to get a clear picture of its dependencies. Knowing what relies on `NF_CT_PROTO_SCTP` and what it requires is critical to understanding its impact and how it fits into the overall architecture. Time to start mapping those connections. Let's see what's linked.

{
  "Expression": "config NF_CT_PROTO_SCTP",
  "PathPrefix": "net/netfilter/Kconfig"
}

{
  "Output": "net/netfilter/Kconfig=198=config NF_CT_PROTO_GRE\n--\nnet/netfilter/Kconfig-200-\nnet/netfilter/Kconfig:201:config NF_CT_PROTO_SCTP\nnet/netfilter/Kconfig-202-\tbool 'SCTP protocol connection tracking support'\n"
}

{
  "File": "net/netfilter/Kconfig",
  "FirstLine": 200,
  "LineCount": 10
}

{
  "Contents": " 200:\t\n 201:\tconfig NF_CT_PROTO_SCTP\n 202:\t\tbool 'SCTP protocol connection tracking support'\n 203:\t\tdepends on NETFILTER_ADVANCED\n 204:\t\tdefault y\n 205:\t\tselect NET_CRC32C\n 206:\t\thelp\n 207:\t\t  With this option enabled, the layer 3 independent connection\n 208:\t\t  tracking code will be able to do state tracking on SCTP connections.\n 209:\t\n"
}

gemini-3.1-pro-preview

null

null

							input: 3963
							output: 32
							thoughts: 90
						

Okay, let's break this down.

**Dependencies and Configuration Checks for SCTP Connection Tracking**

Right, so to enable SCTP connection tracking, it hinges on `NETFILTER_ADVANCED`, which I already knew is a key component. And that, in turn, is part of `NF_CONNTRACK`. So that's the starting point. I need both `NF_CT_PROTO_SCTP` and definitely `NF_CONNTRACK` enabled. The question is, is `NF_CT_PROTO_SCTP` dependent on `NF_CONNTRACK`? I'm pretty sure it is. Let me just quickly confirm that. Yep, it almost certainly lives within an `if NF_CONNTRACK` block. Good. That clarifies the required dependencies.

{
  "Expression": "if NF_CONNTRACK",
  "PathPrefix": "net/netfilter/Kconfig"
}

{
  "Output": "net/netfilter/Kconfig=98=config NF_LOG_SYSLOG\n--\nnet/netfilter/Kconfig-109-\nnet/netfilter/Kconfig:110:if NF_CONNTRACK\nnet/netfilter/Kconfig-111-config NETFILTER_CONNCOUNT\n"
}

gemini-3.1-pro-preview

null

null

							input: 4333
							output: 129
							thoughts: 105
						

**SCTP Connection Tracking Logic Analysis**

Okay, so I've confirmed it's definitely within `NF_CONNTRACK`. Good start. And, specifically, I see that both `NF_CONNTRACK` and `NF_CT_PROTO_SCTP` are the key configurations to be aware of here. The meat of this change seems to revolve around the `nf_conntrack_sctp_packet` function. This is a functional modification, directly impacting the SCTP connection tracking logic. Given that, this is *absolutely* something that warrants fuzzing. We need to really put it through its paces. Now, let's just quickly scan and check if there are any other functions that were also modified that could be a point of focus. Ah, yes, the patch is centered on `nf_conntrack_sctp_packet` specifically. Excellent.

{
  "EnableConfigs": [
    "NF_CONNTRACK",
    "NF_CT_PROTO_SCTP"
  ],
  "FocusSymbols": [
    "nf_conntrack_sctp_packet"
  ],
  "Reasoning": "The patch modifies the SCTP connection tracking logic in netfilter, specifically handling of SCTP_CID_COOKIE_ACK, SCTP_CID_ERROR, SCTP_CID_SHUTDOWN, and SCTP_CID_SHUTDOWN_ACK chunks. This is reachable core kernel logic and should be fuzzed.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "NF_CONNTRACK",
    "NF_CT_PROTO_SCTP"
  ],
  "FocusSymbols": [
    "nf_conntrack_sctp_packet"
  ],
  "Reasoning": "The patch modifies the SCTP connection tracking logic in netfilter, specifically handling of SCTP_CID_COOKIE_ACK, SCTP_CID_ERROR, SCTP_CID_SHUTDOWN, and SCTP_CID_SHUTDOWN_ACK chunks. This is reachable core kernel logic and should be fuzzed.",
  "WorthFuzzing": true
}