AI Trajectory


Trajectory: (Expand/Collapse All)
Seq Timestamp Type Name Duration
0/0 2026/07/01 01:57 flow patch-triage
0m Args: 
null

Results: 
{
  "EnableConfigs": [
    "NFT_CT",
    "NF_NAT"
  ],
  "FocusSymbols": [
    "nft_ct_nat_follow_master",
    "nft_ct_expect_obj_eval"
  ],
  "Reasoning": "The patch introduces a new function `nft_ct_nat_follow_master` and modifies `nft_ct_expect_obj_eval` to use it when `CONFIG_NF_NAT` is enabled and the connection has NAT applied. This adds functional changes to the netfilter connection tracking subsystem, specifically for NAT expectations, which is reachable via nftables and should be fuzzed.",
  "WorthFuzzing": true
}
1/1 2026/07/01 01:57 action read-patch-diff
0m Args: 
null

Results: 
{
  "PatchDiff": "commit a4c6a36629f7aa38bc344470d03f503ada8f13e1\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Wed Jul 1 01:57:24 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c\nindex 03a88c77e0f028..b9dc47b6ca9332 100644\n--- a/net/netfilter/nft_ct.c\n+++ b/net/netfilter/nft_ct.c\n@@ -1297,6 +1297,17 @@ static int nft_ct_expect_obj_dump(struct sk_buff *skb,\n \treturn 0;\n }\n \n+#if IS_ENABLED(CONFIG_NF_NAT)\n+static void nft_ct_nat_follow_master(struct nf_conn *ct, struct nf_conntrack_expect *this)\n+{\n+\tconst struct nf_ct_helper_expectfn *expfn;\n+\n+\texpfn = nf_ct_helper_expectfn_find_by_name(\"nat-follow-master\");\n+\tif (expfn)\n+\t\texpfn-\u003eexpectfn(ct, this);\n+}\n+#endif\n+\n static void nft_ct_expect_obj_eval(struct nft_object *obj,\n \t\t\t\t   struct nft_regs *regs,\n \t\t\t\t   const struct nft_pktinfo *pkt)\n@@ -1342,6 +1353,13 @@ static void nft_ct_expect_obj_eval(struct nft_object *obj,\n \t\t          priv-\u003el4proto, NULL, \u0026priv-\u003edport);\n \texp-\u003etimeout += priv-\u003etimeout;\n \n+#if IS_ENABLED(CONFIG_NF_NAT)\n+\tif (ct-\u003estatus \u0026 IPS_NAT_MASK) {\n+\t\texp-\u003esaved_proto.tcp.port = priv-\u003edport;\n+\t\texp-\u003edir = !dir;\n+\t\texp-\u003eexpectfn = nft_ct_nat_follow_master;\n+\t}\n+#endif\n \tif (nf_ct_expect_related(exp, 0) != 0)\n \t\tregs-\u003everdict.code = NF_DROP;\n \n@@ -1375,6 +1393,11 @@ static struct nft_object_type nft_ct_expect_obj_type __read_mostly = {\n \t.owner\t\t= THIS_MODULE,\n };\n \n+static struct nf_ct_helper_expectfn nft_ct_nat __read_mostly = {\n+\t.name = \"nft_ct-follow-master\",\n+\t.expectfn = nft_ct_nat_follow_master,\n+};\n+\n static int __init nft_ct_module_init(void)\n {\n \tint err;\n@@ -1400,6 +1423,9 @@ static int __init nft_ct_module_init(void)\n \terr = nft_register_obj(\u0026nft_ct_timeout_obj_type);\n \tif (err \u003c 0)\n \t\tgoto err4;\n+#endif\n+#if IS_ENABLED(CONFIG_NF_NAT)\n+\tnf_ct_helper_expectfn_register(\u0026nft_ct_nat);\n #endif\n \treturn 0;\n \n@@ -1425,6 +1451,13 @@ static void __exit nft_ct_module_exit(void)\n \tnft_unregister_obj(\u0026nft_ct_helper_obj_type);\n \tnft_unregister_expr(\u0026nft_notrack_type);\n \tnft_unregister_expr(\u0026nft_ct_type);\n+\n+#if IS_ENABLED(CONFIG_NF_NAT)\n+\tnf_ct_helper_expectfn_unregister(\u0026nft_ct_nat);\n+\tsynchronize_rcu();\n+\tnf_ct_helper_expectfn_destroy(\u0026nft_ct_nat);\n+\tsynchronize_rcu();\n+#endif\n }\n \n module_init(nft_ct_module_init);\n"
}
2/1 2026/07/01 01:57 agent patch-evaluator
0m Model: 
gemini-3.1-pro-preview

Args: 
null

Results: 
{
  "EnableConfigs": [
    "NFT_CT",
    "NF_NAT"
  ],
  "FocusSymbols": [
    "nft_ct_nat_follow_master",
    "nft_ct_expect_obj_eval"
  ],
  "Reasoning": "The patch introduces a new function `nft_ct_nat_follow_master` and modifies `nft_ct_expect_obj_eval` to use it when `CONFIG_NF_NAT` is enabled and the connection has NAT applied. This adds functional changes to the netfilter connection tracking subsystem, specifically for NAT expectations, which is reachable via nftables and should be fuzzed.",
  "WorthFuzzing": true
}

Instruction: 
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.

Prompt: 
For your convenience, here is the diff of the changes:
commit a4c6a36629f7aa38bc344470d03f503ada8f13e1
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Jul 1 01:57:24 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index 03a88c77e0f028..b9dc47b6ca9332 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -1297,6 +1297,17 @@ static int nft_ct_expect_obj_dump(struct sk_buff *skb,
 	return 0;
 }
 
+#if IS_ENABLED(CONFIG_NF_NAT)
+static void nft_ct_nat_follow_master(struct nf_conn *ct, struct nf_conntrack_expect *this)
+{
+	const struct nf_ct_helper_expectfn *expfn;
+
+	expfn = nf_ct_helper_expectfn_find_by_name("nat-follow-master");
+	if (expfn)
+		expfn->expectfn(ct, this);
+}
+#endif
+
 static void nft_ct_expect_obj_eval(struct nft_object *obj,
 				   struct nft_regs *regs,
 				   const struct nft_pktinfo *pkt)
@@ -1342,6 +1353,13 @@ static void nft_ct_expect_obj_eval(struct nft_object *obj,
 		          priv->l4proto, NULL, &priv->dport);
 	exp->timeout += priv->timeout;
 
+#if IS_ENABLED(CONFIG_NF_NAT)
+	if (ct->status & IPS_NAT_MASK) {
+		exp->saved_proto.tcp.port = priv->dport;
+		exp->dir = !dir;
+		exp->expectfn = nft_ct_nat_follow_master;
+	}
+#endif
 	if (nf_ct_expect_related(exp, 0) != 0)
 		regs->verdict.code = NF_DROP;
 
@@ -1375,6 +1393,11 @@ static struct nft_object_type nft_ct_expect_obj_type __read_mostly = {
 	.owner		= THIS_MODULE,
 };
 
+static struct nf_ct_helper_expectfn nft_ct_nat __read_mostly = {
+	.name = "nft_ct-follow-master",
+	.expectfn = nft_ct_nat_follow_master,
+};
+
 static int __init nft_ct_module_init(void)
 {
 	int err;
@@ -1400,6 +1423,9 @@ static int __init nft_ct_module_init(void)
 	err = nft_register_obj(&nft_ct_timeout_obj_type);
 	if (err < 0)
 		goto err4;
+#endif
+#if IS_ENABLED(CONFIG_NF_NAT)
+	nf_ct_helper_expectfn_register(&nft_ct_nat);
 #endif
 	return 0;
 
@@ -1425,6 +1451,13 @@ static void __exit nft_ct_module_exit(void)
 	nft_unregister_obj(&nft_ct_helper_obj_type);
 	nft_unregister_expr(&nft_notrack_type);
 	nft_unregister_expr(&nft_ct_type);
+
+#if IS_ENABLED(CONFIG_NF_NAT)
+	nf_ct_helper_expectfn_unregister(&nft_ct_nat);
+	synchronize_rcu();
+	nf_ct_helper_expectfn_destroy(&nft_ct_nat);
+	synchronize_rcu();
+#endif
 }
 
 module_init(nft_ct_module_init);

3/2 2026/07/01 01:57 llm patch-evaluator
0m Model: 
gemini-3.1-pro-preview

Args: 
null

Results: 
null

Tokens: 
							input: 2545
							output: 28
							thoughts: 186

Thoughts: 
**Analyzing a Netfilter Connection Tracking Patch**

Okay, so I'm looking at this patch that's landed in `net/netfilter/nft_ct.c`. It seems to introduce a new function, `nft_ct_nat_follow_master`, and registers it as an `expectfn`.  That's immediately interesting, as `expectfn` functions are crucial for handling related connections, which is a core part of NAT functionality.

The patch also revises `nft_ct_expect_obj_eval`, and the key here is the conditional usage of `nft_ct_nat_follow_master`. The trigger is when `CONFIG_NF_NAT` is enabled *and* the connection's status (`ct->status`) has the `IPS_NAT_MASK` bit set.  This sounds like it's specifically about connection tracking and NAT, which makes sense given the function name. This suggests that the code is dealing with the cases where NAT is involved and needs to keep track of related connections.

My primary task is to confirm the dependencies and context. I have to confirm that `CONFIG_NF_NAT` is indeed required, and that `nft_ct.c` is compiled under `CONFIG_NFT_CT`. So, I'll need to check the Kconfig and Makefiles in `net/netfilter` directory to confirm these dependencies. I'll need to use `grep` to quickly find how these are configured. Given that this deals with connection tracking, NAT, and related connections, I need to understand exactly how the patch changes the connection tracking behavior, especially in a NAT environment.

4/2 2026/07/01 01:57 tool grepper
0m Args: 
{
  "Expression": "NFT_CT",
  "PathPrefix": "net/netfilter/"
}

Results: 
{
  "Output": "net/netfilter/Kconfig=485=config NFT_NUMGEN\n--\nnet/netfilter/Kconfig-490-\nnet/netfilter/Kconfig:491:config NFT_CT\nnet/netfilter/Kconfig-492-\tdepends on NF_CONNTRACK\n--\nnet/netfilter/Makefile=100=endif\nnet/netfilter/Makefile-101-\nnet/netfilter/Makefile:102:ifdef CONFIG_NFT_CT\nnet/netfilter/Makefile-103-ifdef CONFIG_MITIGATION_RETPOLINE\n--\nnet/netfilter/Makefile=111=obj-$(CONFIG_NFT_NUMGEN)\t+= nft_numgen.o\nnet/netfilter/Makefile:112:obj-$(CONFIG_NFT_CT)\t\t+= nft_ct.o\nnet/netfilter/Makefile-113-obj-$(CONFIG_NFT_FLOW_OFFLOAD)\t+= nft_flow_offload.o\n--\nnet/netfilter/nf_tables_core.c=203=static void expr_call_ops_eval(const struct nft_expr *expr,\n--\nnet/netfilter/nf_tables_core.c-222-\tX(e, nft_lookup_eval);\nnet/netfilter/nf_tables_core.c:223:#if IS_ENABLED(CONFIG_NFT_CT)\nnet/netfilter/nf_tables_core.c-224-\tX(e, nft_ct_get_fast_eval);\n--\nnet/netfilter/nft_ct.c=40=static u64 nft_ct_get_eval_counter(const struct nf_conn_counter *c,\n--\nnet/netfilter/nft_ct.c-44-\tif (d \u003c IP_CT_DIR_MAX)\nnet/netfilter/nft_ct.c:45:\t\treturn k == NFT_CT_BYTES ? atomic64_read(\u0026c[d].bytes) :\nnet/netfilter/nft_ct.c-46-\t\t\t\t\t   atomic64_read(\u0026c[d].packets);\n--\nnet/netfilter/nft_ct.c=52=static void nft_ct_get_eval(const struct nft_expr *expr,\n--\nnet/netfilter/nft_ct.c-67-\tswitch (priv-\u003ekey) {\nnet/netfilter/nft_ct.c:68:\tcase NFT_CT_STATE:\nnet/netfilter/nft_ct.c-69-\t\tif (ct)\n--\nnet/netfilter/nft_ct.c-84-\tswitch (priv-\u003ekey) {\nnet/netfilter/nft_ct.c:85:\tcase NFT_CT_DIRECTION:\nnet/netfilter/nft_ct.c-86-\t\tnft_reg_store8(dest, CTINFO2DIR(ctinfo));\nnet/netfilter/nft_ct.c-87-\t\treturn;\nnet/netfilter/nft_ct.c:88:\tcase NFT_CT_STATUS:\nnet/netfilter/nft_ct.c-89-\t\t*dest = ct-\u003estatus;\n--\nnet/netfilter/nft_ct.c-91-#ifdef CONFIG_NF_CONNTRACK_MARK\nnet/netfilter/nft_ct.c:92:\tcase NFT_CT_MARK:\nnet/netfilter/nft_ct.c-93-\t\t*dest = READ_ONCE(ct-\u003emark);\n--\nnet/netfilter/nft_ct.c-96-#ifdef CONFIG_NF_CONNTRACK_SECMARK\nnet/netfilter/nft_ct.c:97:\tcase NFT_CT_SECMARK:\nnet/netfilter/nft_ct.c-98-\t\t*dest = ct-\u003esecmark;\n--\nnet/netfilter/nft_ct.c-100-#endif\nnet/netfilter/nft_ct.c:101:\tcase NFT_CT_EXPIRATION:\nnet/netfilter/nft_ct.c-102-\t\t*dest = jiffies_to_msecs(nf_ct_expires(ct));\nnet/netfilter/nft_ct.c-103-\t\treturn;\nnet/netfilter/nft_ct.c:104:\tcase NFT_CT_HELPER:\nnet/netfilter/nft_ct.c-105-\t\tif (ct-\u003emaster == NULL)\n--\nnet/netfilter/nft_ct.c-115-#ifdef CONFIG_NF_CONNTRACK_LABELS\nnet/netfilter/nft_ct.c:116:\tcase NFT_CT_LABELS: {\nnet/netfilter/nft_ct.c-117-\t\tstruct nf_conn_labels *labels = nf_ct_labels_find(ct);\n--\nnet/netfilter/nft_ct.c-125-#endif\nnet/netfilter/nft_ct.c:126:\tcase NFT_CT_BYTES:\nnet/netfilter/nft_ct.c:127:\tcase NFT_CT_PKTS: {\nnet/netfilter/nft_ct.c-128-\t\tconst struct nf_conn_acct *acct = nf_conn_acct_find(ct);\n--\nnet/netfilter/nft_ct.c-136-\t}\nnet/netfilter/nft_ct.c:137:\tcase NFT_CT_AVGPKT: {\nnet/netfilter/nft_ct.c-138-\t\tconst struct nf_conn_acct *acct = nf_conn_acct_find(ct);\n--\nnet/netfilter/nft_ct.c-142-\t\t\tpcnt = nft_ct_get_eval_counter(acct-\u003ecounter,\nnet/netfilter/nft_ct.c:143:\t\t\t\t\t\t       NFT_CT_PKTS, priv-\u003edir);\nnet/netfilter/nft_ct.c-144-\t\t\tbcnt = nft_ct_get_eval_counter(acct-\u003ecounter,\nnet/netfilter/nft_ct.c:145:\t\t\t\t\t\t       NFT_CT_BYTES, priv-\u003edir);\nnet/netfilter/nft_ct.c-146-\t\t\tif (pcnt != 0)\n--\nnet/netfilter/nft_ct.c-152-\t}\nnet/netfilter/nft_ct.c:153:\tcase NFT_CT_L3PROTOCOL:\nnet/netfilter/nft_ct.c-154-\t\tnft_reg_store8(dest, nf_ct_l3num(ct));\nnet/netfilter/nft_ct.c-155-\t\treturn;\nnet/netfilter/nft_ct.c:156:\tcase NFT_CT_PROTOCOL:\nnet/netfilter/nft_ct.c-157-\t\tnft_reg_store8(dest, nf_ct_protonum(ct));\n--\nnet/netfilter/nft_ct.c-159-#ifdef CONFIG_NF_CONNTRACK_ZONES\nnet/netfilter/nft_ct.c:160:\tcase NFT_CT_ZONE: {\nnet/netfilter/nft_ct.c-161-\t\tconst struct nf_conntrack_zone *zone = nf_ct_zone(ct);\n--\nnet/netfilter/nft_ct.c-172-#endif\nnet/netfilter/nft_ct.c:173:\tcase NFT_CT_ID:\nnet/netfilter/nft_ct.c-174-\t\t*dest = nf_ct_get_id(ct);\n--\nnet/netfilter/nft_ct.c-181-\tswitch (priv-\u003ekey) {\nnet/netfilter/nft_ct.c:182:\tcase NFT_CT_SRC:\nnet/netfilter/nft_ct.c-183-\t\tmemcpy(dest, tuple-\u003esrc.u3.all, priv-\u003elen);\nnet/netfilter/nft_ct.c-184-\t\treturn;\nnet/netfilter/nft_ct.c:185:\tcase NFT_CT_DST:\nnet/netfilter/nft_ct.c-186-\t\tmemcpy(dest, tuple-\u003edst.u3.all, priv-\u003elen);\nnet/netfilter/nft_ct.c-187-\t\treturn;\nnet/netfilter/nft_ct.c:188:\tcase NFT_CT_PROTO_SRC:\nnet/netfilter/nft_ct.c-189-\t\tnft_reg_store16(dest, (__force u16)tuple-\u003esrc.u.all);\nnet/netfilter/nft_ct.c-190-\t\treturn;\nnet/netfilter/nft_ct.c:191:\tcase NFT_CT_PROTO_DST:\nnet/netfilter/nft_ct.c-192-\t\tnft_reg_store16(dest, (__force u16)tuple-\u003edst.u.all);\nnet/netfilter/nft_ct.c-193-\t\treturn;\nnet/netfilter/nft_ct.c:194:\tcase NFT_CT_SRC_IP:\nnet/netfilter/nft_ct.c-195-\t\tif (nf_ct_l3num(ct) != NFPROTO_IPV4)\n--\nnet/netfilter/nft_ct.c-198-\t\treturn;\nnet/netfilter/nft_ct.c:199:\tcase NFT_CT_DST_IP:\nnet/netfilter/nft_ct.c-200-\t\tif (nf_ct_l3num(ct) != NFPROTO_IPV4)\n--\nnet/netfilter/nft_ct.c-203-\t\treturn;\nnet/netfilter/nft_ct.c:204:\tcase NFT_CT_SRC_IP6:\nnet/netfilter/nft_ct.c-205-\t\tif (nf_ct_l3num(ct) != NFPROTO_IPV6)\n--\nnet/netfilter/nft_ct.c-208-\t\treturn;\nnet/netfilter/nft_ct.c:209:\tcase NFT_CT_DST_IP6:\nnet/netfilter/nft_ct.c-210-\t\tif (nf_ct_l3num(ct) != NFPROTO_IPV6)\n--\nnet/netfilter/nft_ct.c=274=static void nft_ct_set_eval(const struct nft_expr *expr,\n--\nnet/netfilter/nft_ct.c-291-#ifdef CONFIG_NF_CONNTRACK_MARK\nnet/netfilter/nft_ct.c:292:\tcase NFT_CT_MARK:\nnet/netfilter/nft_ct.c-293-\t\tif (READ_ONCE(ct-\u003emark) != value) {\n--\nnet/netfilter/nft_ct.c-299-#ifdef CONFIG_NF_CONNTRACK_SECMARK\nnet/netfilter/nft_ct.c:300:\tcase NFT_CT_SECMARK:\nnet/netfilter/nft_ct.c-301-\t\tif (ct-\u003esecmark != value) {\n--\nnet/netfilter/nft_ct.c-307-#ifdef CONFIG_NF_CONNTRACK_LABELS\nnet/netfilter/nft_ct.c:308:\tcase NFT_CT_LABELS:\nnet/netfilter/nft_ct.c-309-\t\tnf_connlabels_replace(ct,\n--\nnet/netfilter/nft_ct.c-315-#ifdef CONFIG_NF_CONNTRACK_EVENTS\nnet/netfilter/nft_ct.c:316:\tcase NFT_CT_EVENTMASK: {\nnet/netfilter/nft_ct.c-317-\t\tstruct nf_conntrack_ecache *e = nf_ct_ecache_find(ct);\n--\nnet/netfilter/nft_ct.c=382=static void __nft_ct_get_destroy(const struct nft_ctx *ctx, struct nft_ct *priv)\n--\nnet/netfilter/nft_ct.c-384-#ifdef CONFIG_NF_CONNTRACK_LABELS\nnet/netfilter/nft_ct.c:385:\tif (priv-\u003ekey == NFT_CT_LABELS)\nnet/netfilter/nft_ct.c-386-\t\tnf_connlabels_put(ctx-\u003enet);\n--\nnet/netfilter/nft_ct.c=390=static int nft_ct_get_init(const struct nft_ctx *ctx,\n--\nnet/netfilter/nft_ct.c-400-\tswitch (priv-\u003ekey) {\nnet/netfilter/nft_ct.c:401:\tcase NFT_CT_DIRECTION:\nnet/netfilter/nft_ct.c-402-\t\tif (tb[NFTA_CT_DIRECTION] != NULL)\n--\nnet/netfilter/nft_ct.c-405-\t\tbreak;\nnet/netfilter/nft_ct.c:406:\tcase NFT_CT_STATE:\nnet/netfilter/nft_ct.c:407:\tcase NFT_CT_STATUS:\nnet/netfilter/nft_ct.c-408-#ifdef CONFIG_NF_CONNTRACK_MARK\nnet/netfilter/nft_ct.c:409:\tcase NFT_CT_MARK:\nnet/netfilter/nft_ct.c-410-#endif\nnet/netfilter/nft_ct.c-411-#ifdef CONFIG_NF_CONNTRACK_SECMARK\nnet/netfilter/nft_ct.c:412:\tcase NFT_CT_SECMARK:\nnet/netfilter/nft_ct.c-413-#endif\nnet/netfilter/nft_ct.c:414:\tcase NFT_CT_EXPIRATION:\nnet/netfilter/nft_ct.c-415-\t\tif (tb[NFTA_CT_DIRECTION] != NULL)\n--\nnet/netfilter/nft_ct.c-419-#ifdef CONFIG_NF_CONNTRACK_LABELS\nnet/netfilter/nft_ct.c:420:\tcase NFT_CT_LABELS:\nnet/netfilter/nft_ct.c-421-\t\tif (tb[NFTA_CT_DIRECTION] != NULL)\n--\nnet/netfilter/nft_ct.c-429-#endif\nnet/netfilter/nft_ct.c:430:\tcase NFT_CT_HELPER:\nnet/netfilter/nft_ct.c-431-\t\tif (tb[NFTA_CT_DIRECTION] != NULL)\n--\nnet/netfilter/nft_ct.c-435-\nnet/netfilter/nft_ct.c:436:\tcase NFT_CT_L3PROTOCOL:\nnet/netfilter/nft_ct.c:437:\tcase NFT_CT_PROTOCOL:\nnet/netfilter/nft_ct.c-438-\t\t/* For compatibility, do not report error if NFTA_CT_DIRECTION\n--\nnet/netfilter/nft_ct.c-442-\t\tbreak;\nnet/netfilter/nft_ct.c:443:\tcase NFT_CT_SRC:\nnet/netfilter/nft_ct.c:444:\tcase NFT_CT_DST:\nnet/netfilter/nft_ct.c-445-\t\tif (tb[NFTA_CT_DIRECTION] == NULL)\n--\nnet/netfilter/nft_ct.c-461-\t\tbreak;\nnet/netfilter/nft_ct.c:462:\tcase NFT_CT_SRC_IP:\nnet/netfilter/nft_ct.c:463:\tcase NFT_CT_DST_IP:\nnet/netfilter/nft_ct.c-464-\t\tif (tb[NFTA_CT_DIRECTION] == NULL)\n--\nnet/netfilter/nft_ct.c-468-\t\tbreak;\nnet/netfilter/nft_ct.c:469:\tcase NFT_CT_SRC_IP6:\nnet/netfilter/nft_ct.c:470:\tcase NFT_CT_DST_IP6:\nnet/netfilter/nft_ct.c-471-\t\tif (tb[NFTA_CT_DIRECTION] == NULL)\n--\nnet/netfilter/nft_ct.c-475-\t\tbreak;\nnet/netfilter/nft_ct.c:476:\tcase NFT_CT_PROTO_SRC:\nnet/netfilter/nft_ct.c:477:\tcase NFT_CT_PROTO_DST:\nnet/netfilter/nft_ct.c-478-\t\tif (tb[NFTA_CT_DIRECTION] == NULL)\n--\nnet/netfilter/nft_ct.c-481-\t\tbreak;\nnet/netfilter/nft_ct.c:482:\tcase NFT_CT_BYTES:\nnet/netfilter/nft_ct.c:483:\tcase NFT_CT_PKTS:\nnet/netfilter/nft_ct.c:484:\tcase NFT_CT_AVGPKT:\nnet/netfilter/nft_ct.c-485-\t\tlen = sizeof(u64);\n--\nnet/netfilter/nft_ct.c-487-#ifdef CONFIG_NF_CONNTRACK_ZONES\nnet/netfilter/nft_ct.c:488:\tcase NFT_CT_ZONE:\nnet/netfilter/nft_ct.c-489-\t\tlen = sizeof(u16);\n--\nnet/netfilter/nft_ct.c-491-#endif\nnet/netfilter/nft_ct.c:492:\tcase NFT_CT_ID:\nnet/netfilter/nft_ct.c-493-\t\tif (tb[NFTA_CT_DIRECTION])\n--\nnet/netfilter/nft_ct.c-523-\nnet/netfilter/nft_ct.c:524:\tif (priv-\u003ekey == NFT_CT_BYTES ||\nnet/netfilter/nft_ct.c:525:\t    priv-\u003ekey == NFT_CT_PKTS  ||\nnet/netfilter/nft_ct.c:526:\t    priv-\u003ekey == NFT_CT_AVGPKT)\nnet/netfilter/nft_ct.c-527-\t\tnf_ct_set_acct(ctx-\u003enet, true);\n--\nnet/netfilter/nft_ct.c=535=static void __nft_ct_set_destroy(const struct nft_ctx *ctx, struct nft_ct *priv)\n--\nnet/netfilter/nft_ct.c-538-#ifdef CONFIG_NF_CONNTRACK_LABELS\nnet/netfilter/nft_ct.c:539:\tcase NFT_CT_LABELS:\nnet/netfilter/nft_ct.c-540-\t\tnf_connlabels_put(ctx-\u003enet);\n--\nnet/netfilter/nft_ct.c-543-#ifdef CONFIG_NF_CONNTRACK_ZONES\nnet/netfilter/nft_ct.c:544:\tcase NFT_CT_ZONE:\nnet/netfilter/nft_ct.c-545-\t\tnf_queue_nf_hook_drop(ctx-\u003enet);\n--\nnet/netfilter/nft_ct.c=557=static int nft_ct_set_init(const struct nft_ctx *ctx,\n--\nnet/netfilter/nft_ct.c-568-#ifdef CONFIG_NF_CONNTRACK_MARK\nnet/netfilter/nft_ct.c:569:\tcase NFT_CT_MARK:\nnet/netfilter/nft_ct.c-570-\t\tif (tb[NFTA_CT_DIRECTION])\n--\nnet/netfilter/nft_ct.c-575-#ifdef CONFIG_NF_CONNTRACK_LABELS\nnet/netfilter/nft_ct.c:576:\tcase NFT_CT_LABELS:\nnet/netfilter/nft_ct.c-577-\t\tif (tb[NFTA_CT_DIRECTION])\n--\nnet/netfilter/nft_ct.c-585-#ifdef CONFIG_NF_CONNTRACK_ZONES\nnet/netfilter/nft_ct.c:586:\tcase NFT_CT_ZONE:\nnet/netfilter/nft_ct.c-587-\t\tmutex_lock(\u0026nft_ct_pcpu_mutex);\n--\nnet/netfilter/nft_ct.c-597-#ifdef CONFIG_NF_CONNTRACK_EVENTS\nnet/netfilter/nft_ct.c:598:\tcase NFT_CT_EVENTMASK:\nnet/netfilter/nft_ct.c-599-\t\tif (tb[NFTA_CT_DIRECTION])\n--\nnet/netfilter/nft_ct.c-604-#ifdef CONFIG_NF_CONNTRACK_SECMARK\nnet/netfilter/nft_ct.c:605:\tcase NFT_CT_SECMARK:\nnet/netfilter/nft_ct.c-606-\t\tif (tb[NFTA_CT_DIRECTION])\n--\nnet/netfilter/nft_ct.c=661=static int nft_ct_get_dump(struct sk_buff *skb,\n--\nnet/netfilter/nft_ct.c-671-\tswitch (priv-\u003ekey) {\nnet/netfilter/nft_ct.c:672:\tcase NFT_CT_SRC:\nnet/netfilter/nft_ct.c:673:\tcase NFT_CT_DST:\nnet/netfilter/nft_ct.c:674:\tcase NFT_CT_SRC_IP:\nnet/netfilter/nft_ct.c:675:\tcase NFT_CT_DST_IP:\nnet/netfilter/nft_ct.c:676:\tcase NFT_CT_SRC_IP6:\nnet/netfilter/nft_ct.c:677:\tcase NFT_CT_DST_IP6:\nnet/netfilter/nft_ct.c:678:\tcase NFT_CT_PROTO_SRC:\nnet/netfilter/nft_ct.c:679:\tcase NFT_CT_PROTO_DST:\nnet/netfilter/nft_ct.c-680-\t\tif (nla_put_u8(skb, NFTA_CT_DIRECTION, priv-\u003edir))\n--\nnet/netfilter/nft_ct.c-682-\t\tbreak;\nnet/netfilter/nft_ct.c:683:\tcase NFT_CT_BYTES:\nnet/netfilter/nft_ct.c:684:\tcase NFT_CT_PKTS:\nnet/netfilter/nft_ct.c:685:\tcase NFT_CT_AVGPKT:\nnet/netfilter/nft_ct.c:686:\tcase NFT_CT_ZONE:\nnet/netfilter/nft_ct.c-687-\t\tif (priv-\u003edir \u003c IP_CT_DIR_MAX \u0026\u0026\n--\nnet/netfilter/nft_ct.c=701=static int nft_ct_set_dump(struct sk_buff *skb,\n--\nnet/netfilter/nft_ct.c-711-\tswitch (priv-\u003ekey) {\nnet/netfilter/nft_ct.c:712:\tcase NFT_CT_ZONE:\nnet/netfilter/nft_ct.c-713-\t\tif (priv-\u003edir \u003c IP_CT_DIR_MAX \u0026\u0026\n--\nnet/netfilter/nft_ct.c=769=nft_ct_select_ops(const struct nft_ctx *ctx,\n--\nnet/netfilter/nft_ct.c-782-\t\tswitch (k) {\nnet/netfilter/nft_ct.c:783:\t\tcase NFT_CT_STATE:\nnet/netfilter/nft_ct.c:784:\t\tcase NFT_CT_DIRECTION:\nnet/netfilter/nft_ct.c:785:\t\tcase NFT_CT_STATUS:\nnet/netfilter/nft_ct.c:786:\t\tcase NFT_CT_MARK:\nnet/netfilter/nft_ct.c:787:\t\tcase NFT_CT_SECMARK:\nnet/netfilter/nft_ct.c-788-\t\t\treturn \u0026nft_ct_get_fast_ops;\n--\nnet/netfilter/nft_ct.c-795-#ifdef CONFIG_NF_CONNTRACK_ZONES\nnet/netfilter/nft_ct.c:796:\t\tif (nla_get_be32(tb[NFTA_CT_KEY]) == htonl(NFT_CT_ZONE))\nnet/netfilter/nft_ct.c-797-\t\t\treturn \u0026nft_ct_set_zone_ops;\n--\nnet/netfilter/nft_ct_fast.c-1-// SPDX-License-Identifier: GPL-2.0-only\nnet/netfilter/nft_ct_fast.c:2:#if IS_ENABLED(CONFIG_NFT_CT)\nnet/netfilter/nft_ct_fast.c-3-#include \u003clinux/netfilter/nf_tables.h\u003e\n--\nnet/netfilter/nft_ct_fast.c=7=void nft_ct_get_fast_eval(const struct nft_expr *expr,\n--\nnet/netfilter/nft_ct_fast.c-19-\tswitch (priv-\u003ekey) {\nnet/netfilter/nft_ct_fast.c:20:\tcase NFT_CT_STATE:\nnet/netfilter/nft_ct_fast.c-21-\t\tif (ct)\n--\nnet/netfilter/nft_ct_fast.c-38-\tswitch (priv-\u003ekey) {\nnet/netfilter/nft_ct_fast.c:39:\tcase NFT_CT_DIRECTION:\nnet/netfilter/nft_ct_fast.c-40-\t\tnft_reg_store8(dest, CTINFO2DIR(ctinfo));\nnet/netfilter/nft_ct_fast.c-41-\t\treturn;\nnet/netfilter/nft_ct_fast.c:42:\tcase NFT_CT_STATUS:\nnet/netfilter/nft_ct_fast.c-43-\t\t*dest = ct-\u003estatus;\n--\nnet/netfilter/nft_ct_fast.c-45-#ifdef CONFIG_NF_CONNTRACK_MARK\nnet/netfilter/nft_ct_fast.c:46:\tcase NFT_CT_MARK:\nnet/netfilter/nft_ct_fast.c-47-\t\t*dest = ct-\u003emark;\n--\nnet/netfilter/nft_ct_fast.c-50-#ifdef CONFIG_NF_CONNTRACK_SECMARK\nnet/netfilter/nft_ct_fast.c:51:\tcase NFT_CT_SECMARK:\nnet/netfilter/nft_ct_fast.c-52-\t\t*dest = ct-\u003esecmark;\n"
}
5/2 2026/07/01 01:57 llm patch-evaluator
0m Model: 
gemini-3.1-pro-preview

Args: 
null

Results: 
null

Tokens: 
							input: 9609
							output: 30
							thoughts: 293

Thoughts: 
**Analyzing the `nft_ct_nat_follow_master` Function**

Okay, so I'm looking at how the `nft_ct_nat_follow_master` function is used. I'm focusing on the configuration options, specifically `CONFIG_NFT_CT` and `CONFIG_NF_NAT`. My immediate thought is to verify whether `CONFIG_NF_NAT` is a boolean or tristate, and if it has any dependencies. I see the code is in `net/netfilter/nft_ct.c`, which makes sense.

Now I'm tracing the execution path. The `nft_ct_nat_follow_master` function is clearly guarded by `#if IS_ENABLED(CONFIG_NF_NAT)`, which confirms its dependency. So, it requires `NF_NAT` and `NFT_CT`. Excellent.

Next, I need to understand if `nft_ct_nat_follow_master` is actually *reachable* in a practical scenario. It's registered as an `expectfn`, which tells me it's part of an expectation handling chain. Let's see how. `nft_ct_expect_obj_eval` calls `nf_ct_expect_related(exp, 0)`. Aha! And, if `ct->status & IPS_NAT_MASK` is true, then `nft_ct_expect_obj_eval` *explicitly* sets `exp->expectfn = nft_ct_nat_follow_master;`. Okay, so `nft_ct_nat_follow_master` gets called when the expectation is fulfilled.

Finally, I see that within `nft_ct_nat_follow_master`, the function calls `nf_ct_helper_expectfn_find_by_name("nat-follow-master")` and executes it. This is interesting. Now, I need to check whether `"nat-follow-master"` exists.

6/2 2026/07/01 01:57 tool grepper
0m Args: 
{
  "Expression": "nat-follow-master",
  "PathPrefix": "net/netfilter/"
}

Results: 
{
  "Output": "net/netfilter/nf_nat_core.c=1169=static struct nf_ct_helper_expectfn follow_master_nat = {\nnet/netfilter/nf_nat_core.c:1170:\t.name\t\t= \"nat-follow-master\",\nnet/netfilter/nf_nat_core.c-1171-\t.expectfn\t= nf_nat_follow_master,\n--\nnet/netfilter/nft_ct.c=1301=static void nft_ct_nat_follow_master(struct nf_conn *ct, struct nf_conntrack_expect *this)\n--\nnet/netfilter/nft_ct.c-1304-\nnet/netfilter/nft_ct.c:1305:\texpfn = nf_ct_helper_expectfn_find_by_name(\"nat-follow-master\");\nnet/netfilter/nft_ct.c-1306-\tif (expfn)\n"
}
7/2 2026/07/01 01:57 llm patch-evaluator
0m Model: 
gemini-3.1-pro-preview

Args: 
null

Results: 
null

Tokens: 
							input: 10584
							output: 34
							thoughts: 270

Thoughts: 
**My Analysis of the Patch**

Okay, so I've confirmed the code change is within `nf_nat_core.c` – good, it's definitely in a place where I expect it to be. This means the patch is both functional and reachable, which is a key first step. Now, I need to pinpoint the critical functions affected. Based on the diff, my focus needs to be on `nft_ct_nat_follow_master` and `nft_ct_expect_obj_eval`.

Wait a minute, `nft_ct_expect_obj_eval` *has* been modified, so that definitely needs to be listed within `FocusSymbols`. And `nft_ct_nat_follow_master` is *new*, which makes it a critical addition and also needs to be in `FocusSymbols`. Let me just quickly confirm, are there any other functions touched here?

Alright, let's see. The patch adds `nft_ct_nat_follow_master` and modifies `nft_ct_expect_obj_eval`, as previously noted. It looks like `nft_ct_module_init` and `nft_ct_module_exit` have also been modified. However, those are init/exit functions, so they are not as central to my concern.

Next, I need to ensure that the required configurations are enabled. Are `NFT_CT` and `NF_NAT` the only relevant configs? Let me see… `NFT_CT` depends on `NF_CONNTRACK`, and `NF_NAT` also depends on `NF_CONNTRACK`. So, with `NFT_CT` and `NF_NAT` enabled, I should have everything I need. That's good.

Just to be absolutely certain, I'll quickly double-check that modification to `nft_ct_expect_obj_eval` within `net/netfilter/nft_ct.c` for any potential oversight. I want to make sure I am not missing anything, and that all the critical pieces are well understood!

8/2 2026/07/01 01:57 tool grepper
0m Args: 
{
  "Expression": "nft_ct_expect_obj_eval",
  "PathPrefix": "net/netfilter/"
}

Results: 
{
  "Output": "net/netfilter/nft_ct.c=1301=static void nft_ct_nat_follow_master(struct nf_conn *ct, struct nf_conntrack_expect *this)\n--\nnet/netfilter/nft_ct.c-1310-\nnet/netfilter/nft_ct.c:1311:static void nft_ct_expect_obj_eval(struct nft_object *obj,\nnet/netfilter/nft_ct.c-1312-\t\t\t\t   struct nft_regs *regs,\n--\nnet/netfilter/nft_ct.c=1379=static const struct nft_object_ops nft_ct_expect_obj_ops = {\n--\nnet/netfilter/nft_ct.c-1381-\t.size\t\t= sizeof(struct nft_ct_expect_obj),\nnet/netfilter/nft_ct.c:1382:\t.eval\t\t= nft_ct_expect_obj_eval,\nnet/netfilter/nft_ct.c-1383-\t.init\t\t= nft_ct_expect_obj_init,\n"
}
9/2 2026/07/01 01:57 llm patch-evaluator
0m Model: 
gemini-3.1-pro-preview

Args: 
null

Results: 
null

Tokens: 
							input: 11597
							output: 29
							thoughts: 159

Thoughts: 
**Fuzzing Plan for `nft_ct_expect_obj_ops` Evaluation**

Okay, so the `nft_ct_expect_obj_eval` function is the evaluation function for the `nft_ct_expect_obj_ops`, which means it’s definitely reachable through nftables. That's a good starting point. This patch appears functional, so it's a prime candidate for fuzzing.

My focus should be on the following key symbols: `nft_ct_nat_follow_master` and, of course, `nft_ct_expect_obj_eval`. I'll need to configure my fuzzing setup correctly. Based on the context, I should ensure I have `NFT_CT` and `NF_NAT` enabled in my kernel configuration.

Just to be absolutely sure, I'll double-check if `CONFIG_NF_NAT` is the exact configuration option used within the patch itself, and that `CONFIG_NFT_CT` is the config option for `nft_ct.c`. This will ensure there are no surprises in the testing environment. I'll take a quick look to verify.

10/2 2026/07/01 01:57 tool grepper
0m Args: 
{
  "Expression": "config NF_NAT",
  "PathPrefix": "net/netfilter/"
}

Results: 
{
  "Output": "net/netfilter/Kconfig=398=config NETFILTER_NETLINK_GLUE_CT\n--\nnet/netfilter/Kconfig-406-\nnet/netfilter/Kconfig:407:config NF_NAT\nnet/netfilter/Kconfig-408-\ttristate \"Network Address Translation support\"\n--\nnet/netfilter/Kconfig-415-\nnet/netfilter/Kconfig:416:config NF_NAT_AMANDA\nnet/netfilter/Kconfig-417-\ttristate\n--\nnet/netfilter/Kconfig-420-\nnet/netfilter/Kconfig:421:config NF_NAT_FTP\nnet/netfilter/Kconfig-422-\ttristate\n--\nnet/netfilter/Kconfig-425-\nnet/netfilter/Kconfig:426:config NF_NAT_IRC\nnet/netfilter/Kconfig-427-\ttristate\n--\nnet/netfilter/Kconfig-430-\nnet/netfilter/Kconfig:431:config NF_NAT_SIP\nnet/netfilter/Kconfig-432-\ttristate\n--\nnet/netfilter/Kconfig-435-\nnet/netfilter/Kconfig:436:config NF_NAT_TFTP\nnet/netfilter/Kconfig-437-\ttristate\n--\nnet/netfilter/Kconfig-440-\nnet/netfilter/Kconfig:441:config NF_NAT_REDIRECT\nnet/netfilter/Kconfig-442-\tbool\nnet/netfilter/Kconfig-443-\nnet/netfilter/Kconfig:444:config NF_NAT_MASQUERADE\nnet/netfilter/Kconfig-445-\tbool\nnet/netfilter/Kconfig-446-\nnet/netfilter/Kconfig:447:config NF_NAT_OVS\nnet/netfilter/Kconfig-448-\tbool\n"
}
11/2 2026/07/01 01:57 llm patch-evaluator
0m Model: 
gemini-3.1-pro-preview

Args: 
null

Results: 
null

Tokens: 
							input: 12521
							output: 29
							thoughts: 24

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

**Network Address Translation Configuration Check**

Okay, so we're talking about Network Address Translation, and the name `NF_NAT` is definitely ringing a bell. Let's just confirm that that's the precise module name we're dealing with; no need to be sloppy with the details, even if it seems obvious.

Now, let's pivot and cross-reference. I need to make sure `CONFIG_NFT_CT` is enabled. That particular config option is crucial for certain modern Netfilter features, and it needs to be present for the functionality I'm assuming. Verification is key before moving forward, so I'll check that next.

12/2 2026/07/01 01:57 tool grepper
0m Args: 
{
  "Expression": "config NFT_CT",
  "PathPrefix": "net/netfilter/"
}

Results: 
{
  "Output": "net/netfilter/Kconfig=485=config NFT_NUMGEN\n--\nnet/netfilter/Kconfig-490-\nnet/netfilter/Kconfig:491:config NFT_CT\nnet/netfilter/Kconfig-492-\tdepends on NF_CONNTRACK\n"
}
13/2 2026/07/01 01:57 llm patch-evaluator
0m Model: 
gemini-3.1-pro-preview

Args: 
null

Results: 
null

Tokens: 
							input: 12807
							output: 145
							thoughts: 106

Thoughts: 
**My Assessment of the `NFT_CT` Patch**

Okay, so I've just reviewed this patch and, yes, the name `NFT_CT` is spot on. That's the correct identifier for this functionality.

The logic here is sound: they've introduced a new function, `nft_ct_nat_follow_master`, and modified `nft_ct_expect_obj_eval` to leverage this new function. The key point is that this change *only* happens when `CONFIG_NF_NAT` is active, and the specific connection has NAT applied. This is a targeted modification to the Netfilter connection tracking subsystem, specifically dealing with NAT expectations, and, critically, it's all accessible through nftables. Because of this added functionality I can see that this is something that needs to be fuzzed. The changes are very clear, so there is no ambiguity.

I'm going to get on the phone and call set-results.

14/2 2026/07/01 01:57 tool set-results
0m Args: 
{
  "EnableConfigs": [
    "NFT_CT",
    "NF_NAT"
  ],
  "FocusSymbols": [
    "nft_ct_nat_follow_master",
    "nft_ct_expect_obj_eval"
  ],
  "Reasoning": "The patch introduces a new function `nft_ct_nat_follow_master` and modifies `nft_ct_expect_obj_eval` to use it when `CONFIG_NF_NAT` is enabled and the connection has NAT applied. This adds functional changes to the netfilter connection tracking subsystem, specifically for NAT expectations, which is reachable via nftables and should be fuzzed.",
  "WorthFuzzing": true
}

Results: 
{
  "EnableConfigs": [
    "NFT_CT",
    "NF_NAT"
  ],
  "FocusSymbols": [
    "nft_ct_nat_follow_master",
    "nft_ct_expect_obj_eval"
  ],
  "Reasoning": "The patch introduces a new function `nft_ct_nat_follow_master` and modifies `nft_ct_expect_obj_eval` to use it when `CONFIG_NF_NAT` is enabled and the connection has NAT applied. This adds functional changes to the netfilter connection tracking subsystem, specifically for NAT expectations, which is reachable via nftables and should be fuzzed.",
  "WorthFuzzing": true
}
LLM Calls Summary:
Total Calls Total Tokens Avg Tokens Total Duration (Seconds) Avg Duration (Seconds)
Tool Calls Summary:
Total Calls Total Duration (Seconds) Avg Duration (Seconds)