AI Trajectory

null

{
  "EnableConfigs": [
    "IP_SCTP"
  ],
  "FocusSymbols": [
    "sctp_verify_init",
    "sctp_sf_do_5_1B_init",
    "sctp_sf_do_5_1C_ack",
    "sctp_sf_do_5_1D_ce"
  ],
  "Reasoning": "The patch adds a missing length check for the SCTP_PARAM_ADAPTATION_LAYER_IND parameter during SCTP INIT/INIT_ACK chunk processing. This is a functional change in the core SCTP protocol implementation that prevents potential out-of-bounds reads or invalid state, and should be fuzzed.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit 46d1ba178c38bd6175f28cdbbd0b429501e3f585\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Tue Jul 28 19:11:48 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c\nindex c02809264075f..1f7a097802b48 100644\n--- a/net/sctp/sm_make_chunk.c\n+++ b/net/sctp/sm_make_chunk.c\n@@ -2168,7 +2168,13 @@ static enum sctp_ierror sctp_verify_param(struct net *net,\n \tcase SCTP_PARAM_HEARTBEAT_INFO:\n \tcase SCTP_PARAM_UNRECOGNIZED_PARAMETERS:\n \tcase SCTP_PARAM_ECN_CAPABLE:\n+\t\tbreak;\n \tcase SCTP_PARAM_ADAPTATION_LAYER_IND:\n+\t\tif (ntohs(param.p-\u003elength) != sizeof(*param.aind)) {\n+\t\t\tsctp_process_inv_paramlength(asoc, param.p,\n+\t\t\t\t\t\t     chunk, err_chunk);\n+\t\t\tretval = SCTP_IERROR_ABORT;\n+\t\t}\n \t\tbreak;\n \n \tcase SCTP_PARAM_SUPPORTED_EXT:\n"
}

best-expensive

null

{
  "EnableConfigs": [
    "IP_SCTP"
  ],
  "FocusSymbols": [
    "sctp_verify_init",
    "sctp_sf_do_5_1B_init",
    "sctp_sf_do_5_1C_ack",
    "sctp_sf_do_5_1D_ce"
  ],
  "Reasoning": "The patch adds a missing length check for the SCTP_PARAM_ADAPTATION_LAYER_IND parameter during SCTP INIT/INIT_ACK chunk processing. This is a functional change in the core SCTP protocol implementation that prevents potential out-of-bounds reads or invalid state, 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 46d1ba178c38bd6175f28cdbbd0b429501e3f585
Author: syz-cluster <triage@syzkaller.com>
Date:   Tue Jul 28 19:11:48 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index c02809264075f..1f7a097802b48 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -2168,7 +2168,13 @@ static enum sctp_ierror sctp_verify_param(struct net *net,
 	case SCTP_PARAM_HEARTBEAT_INFO:
 	case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
 	case SCTP_PARAM_ECN_CAPABLE:
+		break;
 	case SCTP_PARAM_ADAPTATION_LAYER_IND:
+		if (ntohs(param.p->length) != sizeof(*param.aind)) {
+			sctp_process_inv_paramlength(asoc, param.p,
+						     chunk, err_chunk);
+			retval = SCTP_IERROR_ABORT;
+		}
 		break;
 
 	case SCTP_PARAM_SUPPORTED_EXT:

gemini-3.1-pro-preview

null

null

							input: 2147
							output: 40
							thoughts: 106
						

**Analyzing the SCTP Parameter Verification Patch**

Okay, so I'm looking at this patch in `net/sctp/sm_make_chunk.c`, specifically around the `sctp_verify_param` function. It seems to be adding a crucial length check, targeting the `SCTP_PARAM_ADAPTATION_LAYER_IND` parameter. My initial thought is this is likely a security fix or a robustness improvement.

The logic is straightforward: verify the length of this specific parameter. If the length is determined to be invalid, we invoke `sctp_process_inv_paramlength`, and this, in turn, results in `SCTP_IERROR_ABORT`. This suggests a deliberate, possibly aggressive, response to a potentially malformed or malicious adaptation layer indication.

Now, I need to dig deeper into the context of `sctp_verify_param`. I want to understand *where* this function is being called from. I need to figure out the overall implications and vulnerabilities being addressed here. Is this reacting to a known exploit? Is there any public documentation surrounding this? Is there a CVE attached?

{
  "Expression": "sctp_verify_param",
  "PathPrefix": "net/sctp/sm_make_chunk.c"
}

{
  "Output": "net/sctp/sm_make_chunk.c=2091=static enum sctp_ierror sctp_process_unk_param(\n--\nnet/sctp/sm_make_chunk.c-2143- */\nnet/sctp/sm_make_chunk.c:2144:static enum sctp_ierror sctp_verify_param(struct net *net,\nnet/sctp/sm_make_chunk.c-2145-\t\t\t\t\t  const struct sctp_endpoint *ep,\n--\nnet/sctp/sm_make_chunk.c=2278=int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,\n--\nnet/sctp/sm_make_chunk.c-2321-\tsctp_walk_params(param, peer_init) {\nnet/sctp/sm_make_chunk.c:2322:\t\tresult = sctp_verify_param(net, ep, asoc, param, cid,\nnet/sctp/sm_make_chunk.c-2323-\t\t\t\t\t   chunk, errp);\n--\nnet/sctp/sm_make_chunk.c=2529=static int sctp_process_param(struct sctp_association *asoc,\n--\nnet/sctp/sm_make_chunk.c-2730-\t\t/* Any unrecognized parameters should have been caught\nnet/sctp/sm_make_chunk.c:2731:\t\t * and handled by sctp_verify_param() which should be\nnet/sctp/sm_make_chunk.c-2732-\t\t * called prior to this routine.  Simply log the error\n"
}

gemini-3.1-pro-preview

null

null

							input: 2976
							output: 33
							thoughts: 41
						

Okay, here's my take on those thoughts, framed as my own:

**Investigating the SCTP Parameter Verification**

Alright, so the `sctp_verify_param` function is clearly crucial, since it's being called from `sctp_verify_init`. I need to understand the call chain and what this verification process is really doing. The first thing I'll do is figure out where `sctp_verify_init` itself is being called from. Knowing the entry points will give me the context I need to properly analyze the function and its purpose within the Stream Control Transmission Protocol. Let's trace back from that initialization function and see what we find. I'm expecting some kind of socket initialization or association setup, but I need the broader view to be sure.

{
  "Expression": "sctp_verify_init",
  "PathPrefix": "net/sctp/"
}

{
  "Output": "net/sctp/sm_make_chunk.c=2144=static enum sctp_ierror sctp_verify_param(struct net *net,\n--\nnet/sctp/sm_make_chunk.c-2277-/* Verify the INIT packet before we process it.  */\nnet/sctp/sm_make_chunk.c:2278:int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,\nnet/sctp/sm_make_chunk.c-2279-\t\t     const struct sctp_association *asoc, enum sctp_cid cid,\n--\nnet/sctp/sm_statefuns.c=319=enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,\n--\nnet/sctp/sm_statefuns.c-376-\terr_chunk = NULL;\nnet/sctp/sm_statefuns.c:377:\tif (!sctp_verify_init(net, ep, asoc, chunk-\u003echunk_hdr-\u003etype,\nnet/sctp/sm_statefuns.c-378-\t\t\t      (struct sctp_init_chunk *)chunk-\u003echunk_hdr, chunk,\n--\nnet/sctp/sm_statefuns.c-454-\t\t/* Get the \"Unrecognized parameter\" parameter(s) out of the\nnet/sctp/sm_statefuns.c:455:\t\t * ERROR chunk generated by sctp_verify_init(). Since the\nnet/sctp/sm_statefuns.c-456-\t\t * error cause code for \"unknown parameter\" and the\n--\nnet/sctp/sm_statefuns.c=521=enum sctp_disposition sctp_sf_do_5_1C_ack(struct net *net,\n--\nnet/sctp/sm_statefuns.c-551-\terr_chunk = NULL;\nnet/sctp/sm_statefuns.c:552:\tif (!sctp_verify_init(net, ep, asoc, chunk-\u003echunk_hdr-\u003etype,\nnet/sctp/sm_statefuns.c-553-\t\t\t      (struct sctp_init_chunk *)chunk-\u003echunk_hdr, chunk,\n--\nnet/sctp/sm_statefuns.c=703=enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,\n--\nnet/sctp/sm_statefuns.c-792-\tif (!sctp_sk(sk)-\u003ecookie_auth_enable \u0026\u0026\nnet/sctp/sm_statefuns.c:793:\t    !sctp_verify_init(net, ep, asoc, cid, peer_init, chunk,\nnet/sctp/sm_statefuns.c-794-\t\t\t      \u0026err_chk_p)) {\n--\nnet/sctp/sm_statefuns.c=1529=static enum sctp_disposition sctp_sf_do_unexpected_init(\n--\nnet/sctp/sm_statefuns.c-1582-\terr_chunk = NULL;\nnet/sctp/sm_statefuns.c:1583:\tif (!sctp_verify_init(net, ep, asoc, chunk-\u003echunk_hdr-\u003etype,\nnet/sctp/sm_statefuns.c-1584-\t\t\t      (struct sctp_init_chunk *)chunk-\u003echunk_hdr, chunk,\n--\nnet/sctp/sm_statefuns.c-1678-\t\t/* Get the \"Unrecognized parameter\" parameter(s) out of the\nnet/sctp/sm_statefuns.c:1679:\t\t * ERROR chunk generated by sctp_verify_init(). Since the\nnet/sctp/sm_statefuns.c-1680-\t\t * error cause code for \"unknown parameter\" and the\n--\nnet/sctp/sm_statefuns.c=2224=enum sctp_disposition sctp_sf_do_5_2_4_dupcook(\n--\nnet/sctp/sm_statefuns.c-2309-\t\tif (!sctp_sk(ep-\u003ebase.sk)-\u003ecookie_auth_enable \u0026\u0026\nnet/sctp/sm_statefuns.c:2310:\t\t    !sctp_verify_init(net, ep, asoc, cid, peer_init, chunk,\nnet/sctp/sm_statefuns.c-2311-\t\t\t\t      \u0026err_chk_p)) {\n"
}

gemini-3.1-pro-preview

null

null

							input: 4402
							output: 32
							thoughts: 184
						

**SCTP Parameter Vulnerability: Initial Assessment**

Okay, so this patch immediately flags a potential issue. It's about a missing length check for the `SCTP_PARAM_ADAPTATION_LAYER_IND` parameter specifically within the INIT or INIT_ACK chunks of the SCTP protocol. This is definitely a functional change in the core SCTP implementation, which is something I need to fully investigate.

My initial thought is to ensure this gets fuzzed thoroughly. We need to explore the potential for injection or overflow vulnerabilities. Let me map out the relevant functions in my head, focusing on the ones I need to inspect: `sctp_verify_param` (that's static, so it's likely a helper), `sctp_verify_init` (which is non-static and, therefore, more interesting in terms of potential modification points), `sctp_sf_do_5_1B_init`, `sctp_sf_do_5_1C_ack`, `sctp_sf_do_5_1D_ce`, `sctp_sf_do_unexpected_init`, and `sctp_sf_do_5_2_4_dupcook`. These are the state functions involved in INIT and INIT_ACK processing, so this is where I would start the code review.

Before I dive too deep into the code, I'll quickly check the Kconfig configuration for SCTP to confirm that this change is for an enabled SCTP implementation. That's always a necessary first step. Then, I can start looking at where the parameter is handled and how it's used.

{
  "Expression": "config IP_SCTP",
  "PathPrefix": "net/sctp/"
}

{
  "Output": "net/sctp/Kconfig-5-\nnet/sctp/Kconfig:6:menuconfig IP_SCTP\nnet/sctp/Kconfig-7-\ttristate \"The SCTP Protocol\"\n"
}

gemini-3.1-pro-preview

null

null

							input: 5036
							output: 36
							thoughts: 104
						

**Examining the SCTP Configuration**

Okay, so the configuration in question is `IP_SCTP`. My immediate task is to confirm that a crucial initialization function, specifically `sctp_verify_init`, is accessible and properly defined. I need to ensure it's exported and not declared as `static`. It looks like this function is declared as `int sctp_verify_init(...)` within `net/sctp/sm_make_chunk.c`, which seems appropriate.

Now, considering the state machine context, it's also worth checking the state functions. Specifically, `sctp_sf_do_5_1B_init` and others like it could be relevant candidates for further inspection.

I also should give some thought to checking `sctp_process_inv_paramlength` as another point of focus.

{
  "Expression": "sctp_process_inv_paramlength",
  "PathPrefix": "net/sctp/"
}

{
  "Output": "net/sctp/sm_make_chunk.c=1934=static int sctp_process_inv_mandatory(const struct sctp_association *asoc,\n--\nnet/sctp/sm_make_chunk.c-1949-\nnet/sctp/sm_make_chunk.c:1950:static int sctp_process_inv_paramlength(const struct sctp_association *asoc,\nnet/sctp/sm_make_chunk.c-1951-\t\t\t\t\tstruct sctp_paramhdr *param,\n--\nnet/sctp/sm_make_chunk.c=2144=static enum sctp_ierror sctp_verify_param(struct net *net,\n--\nnet/sctp/sm_make_chunk.c-2173-\t\tif (ntohs(param.p-\u003elength) != sizeof(*param.aind)) {\nnet/sctp/sm_make_chunk.c:2174:\t\t\tsctp_process_inv_paramlength(asoc, param.p,\nnet/sctp/sm_make_chunk.c-2175-\t\t\t\t\t\t     chunk, err_chunk);\n--\nnet/sctp/sm_make_chunk.c-2190-\t\t\t\t\t     sizeof(struct sctp_paramhdr)) {\nnet/sctp/sm_make_chunk.c:2191:\t\t\tsctp_process_inv_paramlength(asoc, param.p,\nnet/sctp/sm_make_chunk.c-2192-\t\t\t\t\t\t     chunk, err_chunk);\n--\nnet/sctp/sm_make_chunk.c-2218-\t\t\t\t\t       sizeof(struct sctp_paramhdr)) {\nnet/sctp/sm_make_chunk.c:2219:\t\t\tsctp_process_inv_paramlength(asoc, param.p,\nnet/sctp/sm_make_chunk.c-2220-\t\t\t\t\t\t     chunk, err_chunk);\n--\nnet/sctp/sm_make_chunk.c-2234-\t\tif (260 \u003c ntohs(param.p-\u003elength)) {\nnet/sctp/sm_make_chunk.c:2235:\t\t\tsctp_process_inv_paramlength(asoc, param.p,\nnet/sctp/sm_make_chunk.c-2236-\t\t\t\t\t\t     chunk, err_chunk);\n--\nnet/sctp/sm_make_chunk.c-2260-\t\tif (id != SCTP_AUTH_HMAC_ID_SHA1) {\nnet/sctp/sm_make_chunk.c:2261:\t\t\tsctp_process_inv_paramlength(asoc, param.p, chunk,\nnet/sctp/sm_make_chunk.c-2262-\t\t\t\t\t\t     err_chunk);\n--\nnet/sctp/sm_make_chunk.c=2278=int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,\n--\nnet/sctp/sm_make_chunk.c-2310-\t\t       SCTP_PAD4(ntohs(peer_init-\u003echunk_hdr.length)))\nnet/sctp/sm_make_chunk.c:2311:\t\treturn sctp_process_inv_paramlength(asoc, param.p, chunk, errp);\nnet/sctp/sm_make_chunk.c-2312-\n"
}

gemini-3.1-pro-preview

null

null

							input: 6239
							output: 163
							thoughts: 113
						

**My Analysis of this SCTP Patch**

Okay, so I'm looking at this patch and immediately, `sctp_verify_init` and `sctp_sf_do_5_1B_init` are the key symbols to focus on here – those functions are critical to the INIT/INIT_ACK chunk processing. The configuration context, in this case, is `IP_SCTP`, which I know very well.

The meat of this change is a missing length check for the `SCTP_PARAM_ADAPTATION_LAYER_IND` parameter. This is a pretty fundamental bug fix, actually. It's in the core SCTP protocol implementation. Without the check, we're talking about a classic out-of-bounds read vulnerability or potentially, an invalid state being entered. We're talking about a reliability or security issue, depending on how it's exploited. Given the nature of this patch, fuzzing this area is absolutely essential. It's the right thing to do to make sure this is thoroughly tested for any future edge cases.

{
  "EnableConfigs": [
    "IP_SCTP"
  ],
  "FocusSymbols": [
    "sctp_verify_init",
    "sctp_sf_do_5_1B_init",
    "sctp_sf_do_5_1C_ack",
    "sctp_sf_do_5_1D_ce"
  ],
  "Reasoning": "The patch adds a missing length check for the SCTP_PARAM_ADAPTATION_LAYER_IND parameter during SCTP INIT/INIT_ACK chunk processing. This is a functional change in the core SCTP protocol implementation that prevents potential out-of-bounds reads or invalid state, and should be fuzzed.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "IP_SCTP"
  ],
  "FocusSymbols": [
    "sctp_verify_init",
    "sctp_sf_do_5_1B_init",
    "sctp_sf_do_5_1C_ack",
    "sctp_sf_do_5_1D_ce"
  ],
  "Reasoning": "The patch adds a missing length check for the SCTP_PARAM_ADAPTATION_LAYER_IND parameter during SCTP INIT/INIT_ACK chunk processing. This is a functional change in the core SCTP protocol implementation that prevents potential out-of-bounds reads or invalid state, and should be fuzzed.",
  "WorthFuzzing": true
}