AI Trajectory

null

{
  "EnableConfigs": [
    "NET_SCHED",
    "NET_CLS_ACT",
    "NET_ACT_NAT",
    "NET_ACT_PEDIT"
  ],
  "FocusSymbols": [
    "tcf_nat_act",
    "tcf_pedit_act"
  ],
  "KMSANReasoning": "The patch fixes conntrack state tracking when packets are modified by tc actions (NAT and pedit). It does so by calling `nf_reset_ct(skb)` to clear the conntrack state if L3/L4 headers are modified. This change only affects packet metadata (skb-\u003enfct) and does not introduce any new data structures, allocations, or data copied to user space. There is no risk of uninitialized memory usage or info-leaks. Standard KASAN and other bug detectors are sufficient to catch any potential memory corruption or use-after-free bugs related to skb manipulation.",
  "NeedsKMSAN": false,
  "Reasoning": "The patch adds `nf_reset_ct(skb)` to `tcf_nat_act` and `tcf_pedit_act` when L3/L4 headers are modified. This is a functional change in the network scheduling actions (NAT and pedit) which are reachable via traffic control (tc) commands.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit a9cfd7688dcd354428d5c03c39a1ad02bb31aaf7\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Wed Aug 19 21:07:50 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/sched/act_nat.c b/net/sched/act_nat.c\nindex abb332dee836d..0c3d3b89d3499 100644\n--- a/net/sched/act_nat.c\n+++ b/net/sched/act_nat.c\n@@ -257,6 +257,7 @@ TC_INDIRECT_SCOPE int tcf_nat_act(struct sk_buff *skb,\n \t}\n \n out:\n+\tnf_reset_ct(skb);\n \treturn action;\n \n drop:\ndiff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c\nindex d4d47a9921f45..b079257c2b7b6 100644\n--- a/net/sched/act_pedit.c\n+++ b/net/sched/act_pedit.c\n@@ -386,6 +386,7 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,\n \tstruct tcf_pedit *p = to_pedit(a);\n \tstruct tcf_pedit_key_ex *tkey_ex;\n \tstruct tcf_pedit_parms *parms;\n+\tbool l3_l4_changed = false;\n \tstruct tc_pedit_key *tkey;\n \tint i;\n \n@@ -398,7 +399,7 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,\n \ttkey_ex = parms-\u003etcfp_keys_ex;\n \n \tfor (i = parms-\u003etcfp_nkeys; i \u003e 0; i--, tkey++) {\n-\t\tint write_offset, write_len;\n+\t\tint write_offset, write_len, nw_offset;\n \t\tint offset = tkey-\u003eoff;\n \t\tint hoffset = 0;\n \t\tu32 cur_val, val;\n@@ -418,6 +419,8 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,\n \t\t\tgoto bad;\n \t\t}\n \n+\t\tnw_offset = skb_network_offset(skb);\n+\n \t\tif (tkey-\u003eoffmask) {\n \t\t\tu8 *d, _d;\n \t\t\tint at_offset;\n@@ -485,6 +488,19 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,\n \t\t}\n \n \t\tput_unaligned((cur_val \u0026 tkey-\u003emask) ^ val, ptr);\n+\n+\t\t/* Track if L3 or L4 headers were modified:\n+\t\t * - Direct L3/L4 header types\n+\t\t * - ETH header type with offset/length reaching into L3/L4\n+\t\t */\n+\t\tif (htype == TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK ||\n+\t\t    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_IP4 ||\n+\t\t    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_IP6 ||\n+\t\t    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_TCP ||\n+\t\t    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_UDP ||\n+\t\t    (htype == TCA_PEDIT_KEY_EX_HDR_TYPE_ETH \u0026\u0026\n+\t\t     write_offset + (int)sizeof(*ptr) \u003e nw_offset))\n+\t\t\tl3_l4_changed = true;\n \t}\n \n \tgoto done;\n@@ -492,6 +508,9 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,\n bad:\n \ttcf_action_inc_overlimit_qstats(\u0026p-\u003ecommon);\n done:\n+\tif (l3_l4_changed)\n+\t\tnf_reset_ct(skb);\n+\n \treturn parms-\u003eaction;\n }\n \ndiff --git a/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json b/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json\nindex 8ab48def89b6a..18a7737483580 100644\n--- a/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json\n+++ b/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json\n@@ -742,5 +742,173 @@\n         \"teardown\": [\n             \"$TC qdisc del dev $DEV1 clsact\"\n         ]\n+    },\n+    {\n+        \"id\": \"c2a9\",\n+        \"name\": \"Verify conntrack reset after pedit modifies IP protocol\",\n+        \"category\": [\n+            \"actions\",\n+            \"ct\",\n+            \"pedit\",\n+            \"scapy\"\n+        ],\n+        \"plugins\": {\n+            \"requires\": [\n+                \"nsPlugin\",\n+                \"scapyPlugin\"\n+            ]\n+        },\n+        \"setup\": [\n+            [\n+                \"$TC qdisc del dev $DEV1 ingress\",\n+                0,\n+                1,\n+                2,\n+                255\n+            ],\n+            \"iptables -t raw -F\",\n+            \"iptables -t raw -A PREROUTING -i $DEV1 -p icmp -m conntrack --ctstate INVALID -j DROP\",\n+            \"$TC qdisc add dev $DEV1 ingress\"\n+        ],\n+        \"cmdUnderTest\": \"$TC filter add dev $DEV1 ingress protocol ip prio 1 flower action ct commit pipe action pedit ex munge ip protocol set 1 pipe action csum ip4h continue\",\n+        \"scapy\": {\n+            \"iface\": \"$DEV0\",\n+            \"count\": 1,\n+            \"packet\": \"Ether(type=0x800)/IP(src='10.0.0.10',dst='10.0.0.20',proto=6)/TCP(sport=1234,dport=80,flags='S')\"\n+        },\n+        \"expExitCode\": \"0\",\n+        \"verifyCmd\": \"iptables-save -c -t raw | grep 'ctstate INVALID'\",\n+        \"matchPattern\": \"^\\\\[1:40\\\\]\",\n+        \"matchCount\": \"1\",\n+        \"teardown\": [\n+            \"$TC qdisc del dev $DEV1 ingress\",\n+            \"iptables -t raw -F\"\n+        ]\n+    },\n+    {\n+        \"id\": \"d3b8\",\n+        \"name\": \"Verify conntrack reset after TCP port modification\",\n+        \"category\": [\n+            \"actions\",\n+            \"ct\",\n+            \"pedit\",\n+            \"scapy\"\n+        ],\n+        \"plugins\": {\n+            \"requires\": [\n+                \"nsPlugin\",\n+                \"scapyPlugin\"\n+            ]\n+        },\n+        \"setup\": [\n+            [\n+                \"$TC qdisc del dev $DEV1 ingress\",\n+                0,\n+                1,\n+                2,\n+                255\n+            ],\n+            \"iptables -t raw -F\",\n+            \"iptables -t raw -A PREROUTING -i $DEV1 -p tcp -m conntrack --ctstate INVALID -j DROP\",\n+            \"$TC qdisc add dev $DEV1 ingress\"\n+        ],\n+        \"cmdUnderTest\": \"$TC filter add dev $DEV1 ingress protocol ip prio 1 flower ip_proto tcp action ct commit pipe action pedit ex munge tcp sport set 9999 pipe\",\n+        \"scapy\": {\n+            \"iface\": \"$DEV0\",\n+            \"count\": 1,\n+            \"packet\": \"Ether(type=0x800)/IP(src='10.0.0.10',dst='10.0.0.20')/TCP(sport=1234,dport=80,flags='S')\"\n+        },\n+        \"expExitCode\": \"0\",\n+        \"verifyCmd\": \"iptables-save -c -t raw | grep 'ctstate INVALID'\",\n+        \"matchCount\": \"1\",\n+        \"matchPattern\": \"^\\\\[1:40\\\\]\",\n+        \"teardown\": [\n+            \"$TC qdisc del dev $DEV1 ingress\",\n+            \"iptables -t raw -F\"\n+        ]\n+    },\n+    {\n+        \"id\": \"a1b2\",\n+        \"name\": \"Verify conntrack NOT reset when pedit modifies only MAC\",\n+        \"category\": [\n+            \"actions\",\n+            \"ct\",\n+            \"pedit\",\n+            \"scapy\"\n+        ],\n+        \"plugins\": {\n+            \"requires\": [\n+                \"nsPlugin\",\n+                \"scapyPlugin\"\n+            ]\n+        },\n+        \"setup\": [\n+            [\n+                \"$TC qdisc del dev $DEV1 ingress\",\n+                0,\n+                1,\n+                2,\n+                255\n+            ],\n+            \"iptables -t raw -F\",\n+            \"iptables -t raw -A PREROUTING -i $DEV1 -p icmp -m conntrack --ctstate NEW -j DROP\",\n+            \"$TC qdisc add dev $DEV1 ingress\"\n+        ],\n+        \"cmdUnderTest\": \"$TC filter add dev $DEV1 ingress protocol ip prio 1 flower action ct commit pipe action pedit ex munge eth src set 11:22:33:44:55:66 pipe\",\n+        \"scapy\": {\n+            \"iface\": \"$DEV0\",\n+            \"count\": 1,\n+            \"packet\": \"Ether(src='aa:bb:cc:dd:ee:ff',type=0x800)/IP(src='10.0.0.11',dst='10.0.0.21')/ICMP()\"\n+        },\n+        \"expExitCode\": \"0\",\n+        \"verifyCmd\": \"iptables-save -c -t raw | grep 'ctstate NEW'\",\n+        \"matchPattern\": \"^\\\\[1:28\\\\]\",\n+        \"matchCount\": \"1\",\n+        \"teardown\": [\n+            \"$TC qdisc del dev $DEV1 ingress\",\n+            \"iptables -t raw -F\"\n+        ]\n+    },\n+    {\n+        \"id\": \"b7f4\",\n+        \"name\": \"Verify conntrack reset when ETH write extends into IP layer\",\n+        \"category\": [\n+            \"actions\",\n+            \"ct\",\n+            \"pedit\",\n+            \"scapy\"\n+        ],\n+        \"plugins\": {\n+            \"requires\": [\n+                \"nsPlugin\",\n+                \"scapyPlugin\"\n+            ]\n+        },\n+        \"setup\": [\n+            [\n+                \"$TC qdisc del dev $DEV1 ingress\",\n+                0,\n+                1,\n+                2,\n+                255\n+            ],\n+            \"iptables -t raw -F\",\n+            \"iptables -t raw -A PREROUTING -i $DEV1 -m conntrack --ctstate INVALID -j DROP\",\n+            \"$TC qdisc add dev $DEV1 ingress\"\n+        ],\n+        \"cmdUnderTest\": \"$TC filter add dev $DEV1 ingress protocol ip prio 1 flower action ct commit pipe action pedit ex munge offset 12 u32 set 0x08004500 pipe csum ip4h continue\",\n+        \"scapy\": {\n+            \"iface\": \"$DEV0\",\n+            \"count\": 1,\n+            \"packet\": \"Ether(type=0x800)/IP(src='10.0.0.13',dst='10.0.0.23')/ICMP()\"\n+        },\n+        \"expExitCode\": \"0\",\n+        \"verifyCmd\": \"iptables-save -t raw -c | grep 'ctstate INVALID'\",\n+        \"matchPattern\": \"^\\\\[1:28\\\\]\",\n+        \"matchCount\": \"1\",\n+        \"teardown\": [\n+            \"$TC qdisc del dev $DEV1 ingress\",\n+            \"iptables -t raw -F\"\n+        ]\n     }\n ]\ndiff --git a/tools/testing/selftests/tc-testing/tdc.py b/tools/testing/selftests/tc-testing/tdc.py\nindex 511d66c36a2a0..19b8a1fd1c716 100755\n--- a/tools/testing/selftests/tc-testing/tdc.py\n+++ b/tools/testing/selftests/tc-testing/tdc.py\n@@ -600,6 +600,18 @@ def mp_bins(alltests):\n \n     return (serial, parallel)\n \n+mp_pm = None\n+mp_args = None\n+\n+def __mp_init__(pm, args):\n+    \"\"\"\n+    This function is called once when each worker process starts.\n+    It sets the global variables in the child process's memory space.\n+    \"\"\"\n+    global mp_pm, mp_args\n+    mp_pm = pm\n+    mp_args = args\n+\n def __mp_runner(tests):\n     (_, tsr) = test_runner(mp_pm, mp_args, tests)\n     return tsr._testsuite\n@@ -615,14 +627,13 @@ def test_runner_mp(pm, args, alltests):\n     print(\"Executing {} tests in parallel and {} in serial\".format(len(parallel), len(serial)))\n     print(\"Using {} batches and {} workers\".format(len(batches), args.mp))\n \n-    # We can't pickle these objects so workaround them\n-    global mp_pm\n-    mp_pm = pm\n-\n-    global mp_args\n-    mp_args = args\n-\n-    with Pool(args.mp) as p:\n+    # Use the 'initializer' to pass the unpickleable/shared objects\n+    # to each worker process exactly once upon startup.\n+    with Pool(\n+        processes=args.mp,\n+        initializer=__mp_init__,\n+        initargs=(pm, args)\n+    ) as p:\n         pres = p.map(__mp_runner, batches)\n \n     tsr = TestSuiteReport()\n"
}

best-expensive

null

{
  "EnableConfigs": [
    "NET_SCHED",
    "NET_CLS_ACT",
    "NET_ACT_NAT",
    "NET_ACT_PEDIT"
  ],
  "FocusSymbols": [
    "tcf_nat_act",
    "tcf_pedit_act"
  ],
  "Reasoning": "The patch adds `nf_reset_ct(skb)` to `tcf_nat_act` and `tcf_pedit_act` when L3/L4 headers are modified. This is a functional change in the network scheduling actions (NAT and pedit) which are reachable via traffic control (tc) commands.",
  "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 a9cfd7688dcd354428d5c03c39a1ad02bb31aaf7
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Aug 19 21:07:50 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/sched/act_nat.c b/net/sched/act_nat.c
index abb332dee836d..0c3d3b89d3499 100644
--- a/net/sched/act_nat.c
+++ b/net/sched/act_nat.c
@@ -257,6 +257,7 @@ TC_INDIRECT_SCOPE int tcf_nat_act(struct sk_buff *skb,
 	}
 
 out:
+	nf_reset_ct(skb);
 	return action;
 
 drop:
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index d4d47a9921f45..b079257c2b7b6 100644
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -386,6 +386,7 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 	struct tcf_pedit *p = to_pedit(a);
 	struct tcf_pedit_key_ex *tkey_ex;
 	struct tcf_pedit_parms *parms;
+	bool l3_l4_changed = false;
 	struct tc_pedit_key *tkey;
 	int i;
 
@@ -398,7 +399,7 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 	tkey_ex = parms->tcfp_keys_ex;
 
 	for (i = parms->tcfp_nkeys; i > 0; i--, tkey++) {
-		int write_offset, write_len;
+		int write_offset, write_len, nw_offset;
 		int offset = tkey->off;
 		int hoffset = 0;
 		u32 cur_val, val;
@@ -418,6 +419,8 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 			goto bad;
 		}
 
+		nw_offset = skb_network_offset(skb);
+
 		if (tkey->offmask) {
 			u8 *d, _d;
 			int at_offset;
@@ -485,6 +488,19 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 		}
 
 		put_unaligned((cur_val & tkey->mask) ^ val, ptr);
+
+		/* Track if L3 or L4 headers were modified:
+		 * - Direct L3/L4 header types
+		 * - ETH header type with offset/length reaching into L3/L4
+		 */
+		if (htype == TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK ||
+		    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_IP4 ||
+		    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_IP6 ||
+		    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_TCP ||
+		    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_UDP ||
+		    (htype == TCA_PEDIT_KEY_EX_HDR_TYPE_ETH &&
+		     write_offset + (int)sizeof(*ptr) > nw_offset))
+			l3_l4_changed = true;
 	}
 
 	goto done;
@@ -492,6 +508,9 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 bad:
 	tcf_action_inc_overlimit_qstats(&p->common);
 done:
+	if (l3_l4_changed)
+		nf_reset_ct(skb);
+
 	return parms->action;
 }
 
diff --git a/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json b/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json
index 8ab48def89b6a..18a7737483580 100644
--- a/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json
+++ b/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json
@@ -742,5 +742,173 @@
         "teardown": [
             "$TC qdisc del dev $DEV1 clsact"
         ]
+    },
+    {
+        "id": "c2a9",
+        "name": "Verify conntrack reset after pedit modifies IP protocol",
+        "category": [
+            "actions",
+            "ct",
+            "pedit",
+            "scapy"
+        ],
+        "plugins": {
+            "requires": [
+                "nsPlugin",
+                "scapyPlugin"
+            ]
+        },
+        "setup": [
+            [
+                "$TC qdisc del dev $DEV1 ingress",
+                0,
+                1,
+                2,
+                255
+            ],
+            "iptables -t raw -F",
+            "iptables -t raw -A PREROUTING -i $DEV1 -p icmp -m conntrack --ctstate INVALID -j DROP",
+            "$TC qdisc add dev $DEV1 ingress"
+        ],
+        "cmdUnderTest": "$TC filter add dev $DEV1 ingress protocol ip prio 1 flower action ct commit pipe action pedit ex munge ip protocol set 1 pipe action csum ip4h continue",
+        "scapy": {
+            "iface": "$DEV0",
+            "count": 1,
+            "packet": "Ether(type=0x800)/IP(src='10.0.0.10',dst='10.0.0.20',proto=6)/TCP(sport=1234,dport=80,flags='S')"
+        },
+        "expExitCode": "0",
+        "verifyCmd": "iptables-save -c -t raw | grep 'ctstate INVALID'",
+        "matchPattern": "^\\[1:40\\]",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DEV1 ingress",
+            "iptables -t raw -F"
+        ]
+    },
+    {
+        "id": "d3b8",
+        "name": "Verify conntrack reset after TCP port modification",
+        "category": [
+            "actions",
+            "ct",
+            "pedit",
+            "scapy"
+        ],
+        "plugins": {
+            "requires": [
+                "nsPlugin",
+                "scapyPlugin"
+            ]
+        },
+        "setup": [
+            [
+                "$TC qdisc del dev $DEV1 ingress",
+                0,
+                1,
+                2,
+                255
+            ],
+            "iptables -t raw -F",
+            "iptables -t raw -A PREROUTING -i $DEV1 -p tcp -m conntrack --ctstate INVALID -j DROP",
+            "$TC qdisc add dev $DEV1 ingress"
+        ],
+        "cmdUnderTest": "$TC filter add dev $DEV1 ingress protocol ip prio 1 flower ip_proto tcp action ct commit pipe action pedit ex munge tcp sport set 9999 pipe",
+        "scapy": {
+            "iface": "$DEV0",
+            "count": 1,
+            "packet": "Ether(type=0x800)/IP(src='10.0.0.10',dst='10.0.0.20')/TCP(sport=1234,dport=80,flags='S')"
+        },
+        "expExitCode": "0",
+        "verifyCmd": "iptables-save -c -t raw | grep 'ctstate INVALID'",
+        "matchCount": "1",
+        "matchPattern": "^\\[1:40\\]",
+        "teardown": [
+            "$TC qdisc del dev $DEV1 ingress",
+            "iptables -t raw -F"
+        ]
+    },
+    {
+        "id": "a1b2",
+        "name": "Verify conntrack NOT reset when pedit modifies only MAC",
+        "category": [
+            "actions",
+            "ct",
+            "pedit",
+            "scapy"
+        ],
+        "plugins": {
+            "requires": [
+                "nsPlugin",
+                "scapyPlugin"
+            ]
+        },
+        "setup": [
+            [
+                "$TC qdisc del dev $DEV1 ingress",
+                0,
+                1,
+                2,
+                255
+            ],
+            "iptables -t raw -F",
+            "iptables -t raw -A PREROUTING -i $DEV1 -p icmp -m conntrack --ctstate NEW -j DROP",
+            "$TC qdisc add dev $DEV1 ingress"
+        ],
+        "cmdUnderTest": "$TC filter add dev $DEV1 ingress protocol ip prio 1 flower action ct commit pipe action pedit ex munge eth src set 11:22:33:44:55:66 pipe",
+        "scapy": {
+            "iface": "$DEV0",
+            "count": 1,
+            "packet": "Ether(src='aa:bb:cc:dd:ee:ff',type=0x800)/IP(src='10.0.0.11',dst='10.0.0.21')/ICMP()"
+        },
+        "expExitCode": "0",
+        "verifyCmd": "iptables-save -c -t raw | grep 'ctstate NEW'",
+        "matchPattern": "^\\[1:28\\]",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DEV1 ingress",
+            "iptables -t raw -F"
+        ]
+    },
+    {
+        "id": "b7f4",
+        "name": "Verify conntrack reset when ETH write extends into IP layer",
+        "category": [
+            "actions",
+            "ct",
+            "pedit",
+            "scapy"
+        ],
+        "plugins": {
+            "requires": [
+                "nsPlugin",
+                "scapyPlugin"
+            ]
+        },
+        "setup": [
+            [
+                "$TC qdisc del dev $DEV1 ingress",
+                0,
+                1,
+                2,
+                255
+            ],
+            "iptables -t raw -F",
+            "iptables -t raw -A PREROUTING -i $DEV1 -m conntrack --ctstate INVALID -j DROP",
+            "$TC qdisc add dev $DEV1 ingress"
+        ],
+        "cmdUnderTest": "$TC filter add dev $DEV1 ingress protocol ip prio 1 flower action ct commit pipe action pedit ex munge offset 12 u32 set 0x08004500 pipe csum ip4h continue",
+        "scapy": {
+            "iface": "$DEV0",
+            "count": 1,
+            "packet": "Ether(type=0x800)/IP(src='10.0.0.13',dst='10.0.0.23')/ICMP()"
+        },
+        "expExitCode": "0",
+        "verifyCmd": "iptables-save -t raw -c | grep 'ctstate INVALID'",
+        "matchPattern": "^\\[1:28\\]",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DEV1 ingress",
+            "iptables -t raw -F"
+        ]
     }
 ]
diff --git a/tools/testing/selftests/tc-testing/tdc.py b/tools/testing/selftests/tc-testing/tdc.py
index 511d66c36a2a0..19b8a1fd1c716 100755
--- a/tools/testing/selftests/tc-testing/tdc.py
+++ b/tools/testing/selftests/tc-testing/tdc.py
@@ -600,6 +600,18 @@ def mp_bins(alltests):
 
     return (serial, parallel)
 
+mp_pm = None
+mp_args = None
+
+def __mp_init__(pm, args):
+    """
+    This function is called once when each worker process starts.
+    It sets the global variables in the child process's memory space.
+    """
+    global mp_pm, mp_args
+    mp_pm = pm
+    mp_args = args
+
 def __mp_runner(tests):
     (_, tsr) = test_runner(mp_pm, mp_args, tests)
     return tsr._testsuite
@@ -615,14 +627,13 @@ def test_runner_mp(pm, args, alltests):
     print("Executing {} tests in parallel and {} in serial".format(len(parallel), len(serial)))
     print("Using {} batches and {} workers".format(len(batches), args.mp))
 
-    # We can't pickle these objects so workaround them
-    global mp_pm
-    mp_pm = pm
-
-    global mp_args
-    mp_args = args
-
-    with Pool(args.mp) as p:
+    # Use the 'initializer' to pass the unpickleable/shared objects
+    # to each worker process exactly once upon startup.
+    with Pool(
+        processes=args.mp,
+        initializer=__mp_init__,
+        initargs=(pm, args)
+    ) as p:
         pres = p.map(__mp_runner, batches)
 
     tsr = TestSuiteReport()

gemini-3.1-pro-preview

null

null

							input: 5397
							output: 21
							thoughts: 279
						

**Analyzing the Kernel Patch for Network Scheduling Actions**

Okay, so I'm looking at this patch and my initial thought is, "Ah, it's messing with `net/sched/act_nat.c` and `net/sched/act_pedit.c`." Immediately, I see it's injecting `nf_reset_ct(skb);` into the `tcf_nat_act` and `tcf_pedit_act` functions, but only if L3/L4 headers have been modified. This tells me we're potentially talking about a fundamental shift in how connection tracking interacts with NAT and packet editing within the traffic control framework. This is important stuff, core kernel functionality. These are features exposed through `tc`, so this patch could have some pretty broad implications.

Next step: let's dig into `net/sched/act_nat.c` and `net/sched/act_pedit.c` to confirm. I need to understand the impact of modifying `tcf_nat_act` and `tcf_pedit_act`, the specific functions that are being touched here. Reaching these via `tc` commands...that makes sense. I need to be able to map these changes to how they’re configured.

Time to look up the configuration options. Right, `net/sched/act_nat.c` is linked to `CONFIG_NET_ACT_NAT`, and `net/sched/act_pedit.c` is, naturally, `CONFIG_NET_ACT_PEDIT`. Now I have to go double check those config options to make sure everything's as expected.

{
  "Expression": "CONFIG_NET_ACT_NAT"
}

{
  "Output": "arch/loongarch/configs/loongson32_defconfig=358=CONFIG_NET_ACT_MIRRED=m\narch/loongarch/configs/loongson32_defconfig:359:CONFIG_NET_ACT_NAT=m\narch/loongarch/configs/loongson32_defconfig-360-CONFIG_NET_ACT_BPF=m\n--\narch/loongarch/configs/loongson64_defconfig=374=CONFIG_NET_ACT_MIRRED=m\narch/loongarch/configs/loongson64_defconfig:375:CONFIG_NET_ACT_NAT=m\narch/loongarch/configs/loongson64_defconfig-376-CONFIG_NET_ACT_BPF=m\n--\narch/mips/configs/ip22_defconfig=173=CONFIG_NET_ACT_MIRRED=m\narch/mips/configs/ip22_defconfig:174:CONFIG_NET_ACT_NAT=m\narch/mips/configs/ip22_defconfig-175-CONFIG_NET_ACT_PEDIT=m\n--\narch/mips/configs/ip27_defconfig=78=CONFIG_NET_ACT_MIRRED=m\narch/mips/configs/ip27_defconfig:79:CONFIG_NET_ACT_NAT=m\narch/mips/configs/ip27_defconfig-80-CONFIG_NET_ACT_PEDIT=m\n--\narch/mips/configs/ip30_defconfig=74=CONFIG_NET_ACT_MIRRED=m\narch/mips/configs/ip30_defconfig:75:CONFIG_NET_ACT_NAT=m\narch/mips/configs/ip30_defconfig-76-CONFIG_NET_ACT_PEDIT=m\n--\narch/mips/configs/malta_defconfig=201=CONFIG_NET_ACT_MIRRED=m\narch/mips/configs/malta_defconfig:202:CONFIG_NET_ACT_NAT=m\narch/mips/configs/malta_defconfig-203-CONFIG_NET_ACT_PEDIT=m\n--\narch/mips/configs/malta_kvm_defconfig=205=CONFIG_NET_ACT_MIRRED=m\narch/mips/configs/malta_kvm_defconfig:206:CONFIG_NET_ACT_NAT=m\narch/mips/configs/malta_kvm_defconfig-207-CONFIG_NET_ACT_PEDIT=m\n--\narch/mips/configs/maltaup_xpa_defconfig=202=CONFIG_NET_ACT_MIRRED=m\narch/mips/configs/maltaup_xpa_defconfig:203:CONFIG_NET_ACT_NAT=m\narch/mips/configs/maltaup_xpa_defconfig-204-CONFIG_NET_ACT_PEDIT=m\n--\narch/powerpc/configs/ppc6xx_defconfig=267=CONFIG_NET_ACT_MIRRED=m\narch/powerpc/configs/ppc6xx_defconfig:268:CONFIG_NET_ACT_NAT=m\narch/powerpc/configs/ppc6xx_defconfig-269-CONFIG_NET_ACT_PEDIT=m\n--\narch/s390/configs/debug_defconfig=407=CONFIG_NET_ACT_MIRRED=m\narch/s390/configs/debug_defconfig:408:CONFIG_NET_ACT_NAT=m\narch/s390/configs/debug_defconfig-409-CONFIG_NET_ACT_PEDIT=m\n--\narch/s390/configs/defconfig=397=CONFIG_NET_ACT_MIRRED=m\narch/s390/configs/defconfig:398:CONFIG_NET_ACT_NAT=m\narch/s390/configs/defconfig-399-CONFIG_NET_ACT_PEDIT=m\n--\ninclude/net/tc_wrapper.h=47=static inline int tc_act(struct sk_buff *skb, const struct tc_action *a,\n--\ninclude/net/tc_wrapper.h-104-#endif\ninclude/net/tc_wrapper.h:105:#if IS_BUILTIN(CONFIG_NET_ACT_NAT)\ninclude/net/tc_wrapper.h-106-\tif (a-\u003eops-\u003eact == tcf_nat_act)\n--\ninclude/net/tc_wrapper.h=203=static inline void tc_wrapper_init(void)\n--\ninclude/net/tc_wrapper.h-228-\t\tIS_BUILTIN(CONFIG_NET_ACT_MPLS) +\ninclude/net/tc_wrapper.h:229:\t\tIS_BUILTIN(CONFIG_NET_ACT_NAT) +\ninclude/net/tc_wrapper.h-230-\t\tIS_BUILTIN(CONFIG_NET_ACT_TUNNEL_KEY) +\n--\nnet/sched/Makefile=15=obj-$(CONFIG_NET_ACT_SAMPLE)\t+= act_sample.o\nnet/sched/Makefile:16:obj-$(CONFIG_NET_ACT_NAT)\t+= act_nat.o\nnet/sched/Makefile-17-obj-$(CONFIG_NET_ACT_PEDIT)\t+= act_pedit.o\n--\ntools/testing/selftests/tc-testing/config=88=CONFIG_NET_ACT_SAMPLE=m\ntools/testing/selftests/tc-testing/config:89:CONFIG_NET_ACT_NAT=m\ntools/testing/selftests/tc-testing/config-90-CONFIG_NET_ACT_PEDIT=m\n"
}

gemini-3.1-pro-preview

null

null

							input: 7463
							output: 22
							thoughts: 14
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Investigating `CONFIG_NET_ACT_PEDIT`**

Okay, let's dive into this `CONFIG_NET_ACT_PEDIT` option. My initial thought is to quickly verify what the current state is and what it controls. I'm assuming this relates to the packet editing action, likely within the Netfilter framework, given the naming convention. I'll probably start by checking the kernel config and cross-referencing that with the relevant Netfilter documentation or code.

I need to understand its functionality - does it provide arbitrary packet modification, or is it more constrained? What are the implications if this is enabled or disabled? Security implications are immediately at the forefront of my mind, as packet manipulation is a sensitive area. I need to be sure I understand the attack surface that this option may expose, if any. Is there any particular hardware this is optimized for?

Next, I'll consider its role in various network setups. Is it commonly used in production environments, or is it more of a niche feature? What are the performance considerations? Does it integrate well with other Netfilter components, like iptables or nftables? I want to assess if it's considered a reliable option.

I also want to know whether it has any known issues or limitations, particularly regarding concurrency or edge cases. Are there any known exploits associated with it, or has it been the subject of any vulnerability disclosures?

Finally, what are the use-cases where this option is essential or highly beneficial? What are the alternatives, and how do they compare in terms of performance, security, and flexibility? I'm going to look for any information on the Linux Kernel Mailing List that may indicate any problems.

{
  "Expression": "CONFIG_NET_ACT_PEDIT"
}

{
  "Output": "arch/mips/configs/ip22_defconfig=174=CONFIG_NET_ACT_NAT=m\narch/mips/configs/ip22_defconfig:175:CONFIG_NET_ACT_PEDIT=m\narch/mips/configs/ip22_defconfig-176-CONFIG_NET_ACT_SIMP=m\n--\narch/mips/configs/ip27_defconfig=79=CONFIG_NET_ACT_NAT=m\narch/mips/configs/ip27_defconfig:80:CONFIG_NET_ACT_PEDIT=m\narch/mips/configs/ip27_defconfig-81-CONFIG_NET_ACT_SKBEDIT=m\n--\narch/mips/configs/ip30_defconfig=75=CONFIG_NET_ACT_NAT=m\narch/mips/configs/ip30_defconfig:76:CONFIG_NET_ACT_PEDIT=m\narch/mips/configs/ip30_defconfig-77-CONFIG_NET_ACT_SKBEDIT=m\n--\narch/mips/configs/malta_defconfig=202=CONFIG_NET_ACT_NAT=m\narch/mips/configs/malta_defconfig:203:CONFIG_NET_ACT_PEDIT=m\narch/mips/configs/malta_defconfig-204-CONFIG_NET_ACT_SIMP=m\n--\narch/mips/configs/malta_kvm_defconfig=206=CONFIG_NET_ACT_NAT=m\narch/mips/configs/malta_kvm_defconfig:207:CONFIG_NET_ACT_PEDIT=m\narch/mips/configs/malta_kvm_defconfig-208-CONFIG_NET_ACT_SIMP=m\n--\narch/mips/configs/maltaup_xpa_defconfig=203=CONFIG_NET_ACT_NAT=m\narch/mips/configs/maltaup_xpa_defconfig:204:CONFIG_NET_ACT_PEDIT=m\narch/mips/configs/maltaup_xpa_defconfig-205-CONFIG_NET_ACT_SIMP=m\n--\narch/mips/configs/rb532_defconfig=96=CONFIG_NET_ACT_MIRRED=m\narch/mips/configs/rb532_defconfig:97:CONFIG_NET_ACT_PEDIT=m\narch/mips/configs/rb532_defconfig-98-CONFIG_MTD=y\n--\narch/powerpc/configs/ppc6xx_defconfig=268=CONFIG_NET_ACT_NAT=m\narch/powerpc/configs/ppc6xx_defconfig:269:CONFIG_NET_ACT_PEDIT=m\narch/powerpc/configs/ppc6xx_defconfig-270-CONFIG_NET_ACT_SIMP=m\n--\narch/s390/configs/debug_defconfig=408=CONFIG_NET_ACT_NAT=m\narch/s390/configs/debug_defconfig:409:CONFIG_NET_ACT_PEDIT=m\narch/s390/configs/debug_defconfig-410-CONFIG_NET_ACT_SIMP=m\n--\narch/s390/configs/defconfig=398=CONFIG_NET_ACT_NAT=m\narch/s390/configs/defconfig:399:CONFIG_NET_ACT_PEDIT=m\narch/s390/configs/defconfig-400-CONFIG_NET_ACT_SIMP=m\n--\narch/sh/configs/titan_defconfig=138=CONFIG_NET_ACT_MIRRED=m\narch/sh/configs/titan_defconfig:139:CONFIG_NET_ACT_PEDIT=m\narch/sh/configs/titan_defconfig-140-CONFIG_FW_LOADER=m\n--\ninclude/net/tc_wrapper.h=47=static inline int tc_act(struct sk_buff *skb, const struct tc_action *a,\n--\ninclude/net/tc_wrapper.h-60-#endif\ninclude/net/tc_wrapper.h:61:#if IS_BUILTIN(CONFIG_NET_ACT_PEDIT)\ninclude/net/tc_wrapper.h-62-\tif (a-\u003eops-\u003eact == tcf_pedit_act)\n--\ninclude/net/tc_wrapper.h=203=static inline void tc_wrapper_init(void)\n--\ninclude/net/tc_wrapper.h-217-\t\tIS_BUILTIN(CONFIG_NET_ACT_MIRRED) +\ninclude/net/tc_wrapper.h:218:\t\tIS_BUILTIN(CONFIG_NET_ACT_PEDIT) +\ninclude/net/tc_wrapper.h-219-\t\tIS_BUILTIN(CONFIG_NET_ACT_SKBEDIT) +\n--\nnet/sched/Makefile=16=obj-$(CONFIG_NET_ACT_NAT)\t+= act_nat.o\nnet/sched/Makefile:17:obj-$(CONFIG_NET_ACT_PEDIT)\t+= act_pedit.o\nnet/sched/Makefile-18-obj-$(CONFIG_NET_ACT_SIMP)\t+= act_simple.o\n--\ntools/testing/selftests/net/config=69=CONFIG_NET_ACT_MIRRED=m\ntools/testing/selftests/net/config:70:CONFIG_NET_ACT_PEDIT=m\ntools/testing/selftests/net/config-71-CONFIG_NET_ACT_TUNNEL_KEY=m\n--\ntools/testing/selftests/net/forwarding/config=22=CONFIG_NET_ACT_MPLS=m\ntools/testing/selftests/net/forwarding/config:23:CONFIG_NET_ACT_PEDIT=m\ntools/testing/selftests/net/forwarding/config-24-CONFIG_NET_ACT_POLICE=m\n--\ntools/testing/selftests/net/mptcp/config=15=CONFIG_NET_ACT_CSUM=m\ntools/testing/selftests/net/mptcp/config:16:CONFIG_NET_ACT_PEDIT=m\ntools/testing/selftests/net/mptcp/config-17-CONFIG_NET_CLS_ACT=y\n--\ntools/testing/selftests/tc-testing/config=89=CONFIG_NET_ACT_NAT=m\ntools/testing/selftests/tc-testing/config:90:CONFIG_NET_ACT_PEDIT=m\ntools/testing/selftests/tc-testing/config-91-CONFIG_NET_ACT_SIMP=m\n"
}

gemini-3.1-pro-preview

null

null

							input: 9517
							output: 20
							thoughts: 72
						

**Examining the Kernel Configuration for Network Action Modules**

Okay, so I'm looking into these network action modules, specifically `NET_ACT_NAT` and `NET_ACT_PEDIT`. I know there are functions associated with them – `tcf_nat_act` and `tcf_pedit_act`, respectively. Now, to understand how these modules are configured, I need to dive into the kernel configuration. I'm going to check `net/sched/Kconfig` to see how `NET_ACT_NAT` and `NET_ACT_PEDIT` are defined and what dependencies they might have. This will give me a better handle on their availability and how they can be controlled during kernel builds, which in turn informs how I use them.

{
  "Expression": "config NET_ACT_NAT"
}

{
  "Output": "net/sched/Kconfig=752=config NET_ACT_SAMPLE\n--\nnet/sched/Kconfig-763-\nnet/sched/Kconfig:764:config NET_ACT_NAT\nnet/sched/Kconfig-765-\ttristate \"Stateless NAT\"\n"
}

gemini-3.1-pro-preview

null

null

							input: 9854
							output: 21
							thoughts: 21
						

Here's my take on those thoughts:

**Checking the Kconfig for NET_ACT_PEDIT**

Okay, so I need to quickly refresh my memory on where the configuration option for `NET_ACT_PEDIT` is defined. My first instinct, as always with networking related kernel features, is to look in the `net/sched/Kconfig` file. That's the usual home for scheduling and traffic control related options. I'm assuming it should be in there, but let's just make sure; a quick check will keep me from wasting time if it's been moved elsewhere in a later kernel version or renamed. Time to pull up that file and confirm.

{
  "Expression": "config NET_ACT_PEDIT"
}

{
  "Output": "net/sched/Kconfig=764=config NET_ACT_NAT\n--\nnet/sched/Kconfig-773-\nnet/sched/Kconfig:774:config NET_ACT_PEDIT\nnet/sched/Kconfig-775-\ttristate \"Packet Editing\"\n"
}

gemini-3.1-pro-preview

null

null

							input: 10123
							output: 34
							thoughts: 22
						

Okay, here's my take on those thoughts, framed as an expert's internal monologue:

**Investigating the NET_ACT_NAT Dependencies**

Right, let's dive into the guts of the networking scheduler configuration. The task at hand is to understand the dependencies surrounding `NET_ACT_NAT`. Given my background, I already have a decent grasp of the overall architecture, but a specific dependency check is a good practice to ensure the system is being configured correctly. I need to make sure I haven't overlooked any crucial interconnections within the kernel's scheduling logic. So, `net/sched/Kconfig` is the obvious place to start. That file should contain the conditional logic and relationships that define when `NET_ACT_NAT` is enabled or disabled, and, more importantly, *why*. I'm looking for clues about other related features, configuration options, or kernel modules that might have a direct impact on whether this specific action is available and working as intended. This is about making sure all the pieces fit together seamlessly.

{
  "File": "net/sched/Kconfig",
  "FirstLine": 760,
  "LineCount": 30
}

{
  "Contents": " 760:\t\n 761:\t\t  To compile this code as a module, choose M here: the\n 762:\t\t  module will be called act_sample.\n 763:\t\n 764:\tconfig NET_ACT_NAT\n 765:\t\ttristate \"Stateless NAT\"\n 766:\t\tdepends on NET_CLS_ACT\n 767:\t\thelp\n 768:\t\t  Say Y here to do stateless NAT on IPv4 packets.  You should use\n 769:\t\t  netfilter for NAT unless you know what you are doing.\n 770:\t\n 771:\t\t  To compile this code as a module, choose M here: the\n 772:\t\t  module will be called act_nat.\n 773:\t\n 774:\tconfig NET_ACT_PEDIT\n 775:\t\ttristate \"Packet Editing\"\n 776:\t\tdepends on NET_CLS_ACT\n 777:\t\thelp\n 778:\t\t  Say Y here if you want to mangle the content of packets.\n 779:\t\n 780:\t\t  To compile this code as a module, choose M here: the\n 781:\t\t  module will be called act_pedit.\n 782:\t\n 783:\tconfig NET_ACT_SIMP\n 784:\t\ttristate \"Simple Example (Debug)\"\n 785:\t\tdepends on NET_CLS_ACT\n 786:\t\thelp\n 787:\t\t  Say Y here to add a simple action for demonstration purposes.\n 788:\t\t  It is meant as an example and for debugging purposes. It will\n 789:\t\t  print a configured policy string followed by the packet count\n"
}

gemini-3.1-pro-preview

null

null

							input: 10839
							output: 20
							thoughts: 24
						

Okay, here's my take on those thoughts, framed as an expert's internal monologue:

**Dependencies Deep Dive**

Alright, the core issue seems to revolve around `NET_CLS_ACT`. My initial thought is to immediately zoom in on its dependencies. I need to understand what this feature or module relies upon. A quick scan of the code, or perhaps even a mental map, should reveal the crucial links. I'm thinking I'll need to assess *those* dependencies, because the root problem is most likely stemming from an underlying dependency that is not yet fully configured.

{
  "Expression": "config NET_CLS_ACT"
}

{
  "Output": "net/sched/Kconfig=690=config NET_EMATCH_IPT\n--\nnet/sched/Kconfig-701-\nnet/sched/Kconfig:702:config NET_CLS_ACT\nnet/sched/Kconfig-703-\tbool \"Actions\"\n"
}

gemini-3.1-pro-preview

null

null

							input: 11085
							output: 34
							thoughts: 22
						

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

**Examining the Dependencies of `NET_CLS_ACT`**

Okay, time to dig into the kernel's networking configuration. I need to understand the dependencies of `NET_CLS_ACT`. I'll start by checking the `net/sched/Kconfig` file. I'm assuming it's the right place, but better to be sure. I'm looking for any immediate dependencies like other options, symbols, or even other Kconfig files that `NET_CLS_ACT` might rely on. This is likely a key component for traffic classification and action, but a deeper understanding of its dependencies is key to any modification or troubleshooting. I'll need to know what other features or configurations this is connected to. I'm expecting this will likely point me to other related options that may have an effect on this feature, or other modules that are closely related. This will provide context, and help ensure I don't break anything.

{
  "File": "net/sched/Kconfig",
  "FirstLine": 698,
  "LineCount": 20
}

{
  "Contents": " 698:\t\n 699:\t\t  To compile this code as a module, choose M here: the\n 700:\t\t  module will be called em_ipt.\n 701:\t\n 702:\tconfig NET_CLS_ACT\n 703:\t\tbool \"Actions\"\n 704:\t\tselect NET_CLS\n 705:\t\tselect NET_XGRESS\n 706:\t\thelp\n 707:\t\t  Say Y here if you want to use traffic control actions. Actions\n 708:\t\t  get attached to classifiers and are invoked after a successful\n 709:\t\t  classification. They are used to overwrite the classification\n 710:\t\t  result, instantly drop or redirect packets, etc.\n 711:\t\n 712:\t\t  A recent version of the iproute2 package is required to use\n 713:\t\t  extended matches.\n 714:\t\n 715:\tconfig NET_ACT_POLICE\n 716:\t\ttristate \"Traffic Policing\"\n 717:\t\tdepends on NET_CLS_ACT\n"
}

gemini-3.1-pro-preview

null

null

							input: 11635
							output: 32
							thoughts: 82
						

Okay, let's break this down.

**Network Configuration Dependencies**

Alright, so `NET_CLS_ACT` is acting as a Boolean switch, deciding whether we enable `NET_CLS` and `NET_XGRESS`. Thinking about what's actually needed in the broader picture, the key configurations to enable seem to be `NET_ACT_NAT`, `NET_ACT_PEDIT`, and of course, `NET_CLS_ACT` itself. My gut says we'll also need to enable `NET_SCHED` to get the scheduling aspects working. I should probably double-check that by heading over to the top of `net/sched/Kconfig` to confirm any dependencies or relevant context there. It's always good to be thorough with these network configurations.

{
  "File": "net/sched/Kconfig",
  "FirstLine": 1,
  "LineCount": 20
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0-only\n   2:\t#\n   3:\t# Traffic control configuration.\n   4:\t#\n   5:\t\n   6:\tmenuconfig NET_SCHED\n   7:\t\tbool \"QoS and/or fair queueing\"\n   8:\t\tselect NET_SCH_FIFO\n   9:\t\thelp\n  10:\t\t  When the kernel has several packets to send out over a network\n  11:\t\t  device, it has to decide which ones to send first, which ones to\n  12:\t\t  delay, and which ones to drop. This is the job of the queueing\n  13:\t\t  disciplines, several different algorithms for how to do this\n  14:\t\t  \"fairly\" have been proposed.\n  15:\t\n  16:\t\t  If you say N here, you will get the standard packet scheduler, which\n  17:\t\t  is a FIFO (first come, first served). If you say Y here, you will be\n  18:\t\t  able to choose from among several alternative algorithms which can\n  19:\t\t  then be attached to different network devices. This is useful for\n  20:\t\t  example if some of your network devices are real time devices that\n"
}

gemini-3.1-pro-preview

null

null

							input: 12223
							output: 19
							thoughts: 138
						

**My Initial Assessment of the Network Scheduling Patch**

Okay, so I see this patch is going to hinge on `NET_SCHED`. That's the core. To get this thing working, I'll need to enable `NET_SCHED`, and then I'll definitely want `NET_CLS_ACT`, `NET_ACT_NAT`, and `NET_ACT_PEDIT` too. Those configs are pretty standard for this type of network traffic management. The two primary functions I need to keep an eye on are `tcf_nat_act` and `tcf_pedit_act`. They're probably where the core logic of the NAT and packet editing happen.

Hold on, I see `nf_reset_ct(skb)` being used. That throws a red flag. I know that function is used to reset the connection tracking state. I need to be absolutely sure this won't cause any conflicts and needs to be supported, what Netfilter configurations need to be enabled for this? Time to double check the includes. Is it `include/linux/skbuff.h` or `include/net/netfilter/nf_conntrack.h` that defines it? Let me check those files directly, and verify what's what.

{
  "Expression": "nf_reset_ct"
}

{
  "Output": "drivers/net/ovpn/io.c=356=netdev_tx_t ovpn_net_xmit(struct sk_buff *skb, struct net_device *dev)\n--\ndrivers/net/ovpn/io.c-366-\t/* reset netfilter state */\ndrivers/net/ovpn/io.c:367:\tnf_reset_ct(skb);\ndrivers/net/ovpn/io.c-368-\n--\ndrivers/net/ppp/pptp.c=149=static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)\n--\ndrivers/net/ppp/pptp.c-256-\ndrivers/net/ppp/pptp.c:257:\tnf_reset_ct(skb);\ndrivers/net/ppp/pptp.c-258-\n--\ndrivers/net/ppp/pptp.c=350=static int pptp_rcv(struct sk_buff *skb)\n--\ndrivers/net/ppp/pptp.c-376-\t\tskb_dst_drop(skb);\ndrivers/net/ppp/pptp.c:377:\t\tnf_reset_ct(skb);\ndrivers/net/ppp/pptp.c-378-\t\treturn sk_receive_skb(\u0026po-\u003esk, skb, 0);\n--\ndrivers/net/tun.c=1003=static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)\n--\ndrivers/net/tun.c-1062-\ndrivers/net/tun.c:1063:\tnf_reset_ct(skb);\ndrivers/net/tun.c-1064-\n--\ndrivers/net/virtio_net.c=3336=static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)\n--\ndrivers/net/virtio_net.c-3373-\t\tskb_dst_drop(skb);\ndrivers/net/virtio_net.c:3374:\t\tnf_reset_ct(skb);\ndrivers/net/virtio_net.c-3375-\t}\n--\ndrivers/net/vrf.c=382=static void vrf_nf_set_untracked(struct sk_buff *skb)\n--\ndrivers/net/vrf.c-387-\ndrivers/net/vrf.c:388:static void vrf_nf_reset_ct(struct sk_buff *skb)\ndrivers/net/vrf.c-389-{\ndrivers/net/vrf.c-390-\tif (skb_get_nfct(skb) == IP_CT_UNTRACKED)\ndrivers/net/vrf.c:391:\t\tnf_reset_ct(skb);\ndrivers/net/vrf.c-392-}\n--\ndrivers/net/vrf.c=395=static int vrf_ip6_local_out(struct net *net, struct sock *sk,\n--\ndrivers/net/vrf.c-399-\ndrivers/net/vrf.c:400:\tvrf_nf_reset_ct(skb);\ndrivers/net/vrf.c-401-\n--\ndrivers/net/vrf.c=475=static int vrf_ip_local_out(struct net *net, struct sock *sk,\n--\ndrivers/net/vrf.c-479-\ndrivers/net/vrf.c:480:\tvrf_nf_reset_ct(skb);\ndrivers/net/vrf.c-481-\n--\ndrivers/net/vrf.c=577=static void vrf_finish_direct(struct sk_buff *skb)\n--\ndrivers/net/vrf.c-595-\ndrivers/net/vrf.c:596:\tvrf_nf_reset_ct(skb);\ndrivers/net/vrf.c-597-}\n--\ndrivers/net/vrf.c=601=static int vrf_finish_output6(struct net *net, struct sock *sk,\n--\ndrivers/net/vrf.c-609-\ndrivers/net/vrf.c:610:\tvrf_nf_reset_ct(skb);\ndrivers/net/vrf.c-611-\n--\ndrivers/net/vrf.c=796=static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)\n--\ndrivers/net/vrf.c-804-\ndrivers/net/vrf.c:805:\tvrf_nf_reset_ct(skb);\ndrivers/net/vrf.c-806-\n--\ndrivers/net/wireless/virtual/mac80211_hwsim_main.c=1902=static bool mac80211_hwsim_tx_frame_no_nl(struct ieee80211_hw *hw,\n--\ndrivers/net/wireless/virtual/mac80211_hwsim_main.c-1955-\tskb_ext_reset(skb);\ndrivers/net/wireless/virtual/mac80211_hwsim_main.c:1956:\tnf_reset_ct(skb);\ndrivers/net/wireless/virtual/mac80211_hwsim_main.c-1957-\n--\ndrivers/staging/octeon/ethernet-tx.c=126=netdev_tx_t cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev)\n--\ndrivers/staging/octeon/ethernet-tx.c-350-\tskb_ext_reset(skb);\ndrivers/staging/octeon/ethernet-tx.c:351:\tnf_reset_ct(skb);\ndrivers/staging/octeon/ethernet-tx.c-352-\tskb_reset_redirect(skb);\n--\ninclude/linux/skbuff.h=5133=static inline bool skb_has_extensions(struct sk_buff *skb) { return false; }\n--\ninclude/linux/skbuff.h-5135-\ninclude/linux/skbuff.h:5136:static inline void nf_reset_ct(struct sk_buff *skb)\ninclude/linux/skbuff.h-5137-{\n--\nnet/batman-adv/mesh-interface.c=407=void batadv_interface_rx(struct net_device *mesh_iface,\n--\nnet/batman-adv/mesh-interface.c-426-\t */\nnet/batman-adv/mesh-interface.c:427:\tnf_reset_ct(skb);\nnet/batman-adv/mesh-interface.c-428-\n--\nnet/bridge/br_netfilter_hooks.c=585=static unsigned int br_nf_local_in(void *priv,\n--\nnet/bridge/br_netfilter_hooks.c-595-\tif (promisc) {\nnet/bridge/br_netfilter_hooks.c:596:\t\tnf_reset_ct(skb);\nnet/bridge/br_netfilter_hooks.c-597-\t\treturn NF_ACCEPT;\n--\nnet/bridge/br_netfilter_hooks.c-607-\tif (WARN_ON_ONCE(refcount_read(\u0026nfct-\u003euse) != 1)) {\nnet/bridge/br_netfilter_hooks.c:608:\t\tnf_reset_ct(skb);\nnet/bridge/br_netfilter_hooks.c-609-\t\treturn NF_ACCEPT;\n--\nnet/bridge/netfilter/nf_conntrack_bridge.c=239=static unsigned int nf_ct_bridge_pre(void *priv, struct sk_buff *skb,\n--\nnet/bridge/netfilter/nf_conntrack_bridge.c-282-\tdefault:\nnet/bridge/netfilter/nf_conntrack_bridge.c:283:\t\tnf_reset_ct(skb);\nnet/bridge/netfilter/nf_conntrack_bridge.c-284-\t\tnf_ct_set(skb, NULL, IP_CT_UNTRACKED);\n--\nnet/bridge/netfilter/nf_conntrack_bridge.c=294=static unsigned int nf_ct_bridge_in(void *priv, struct sk_buff *skb,\n--\nnet/bridge/netfilter/nf_conntrack_bridge.c-301-\tif (promisc) {\nnet/bridge/netfilter/nf_conntrack_bridge.c:302:\t\tnf_reset_ct(skb);\nnet/bridge/netfilter/nf_conntrack_bridge.c-303-\t\treturn NF_ACCEPT;\n--\nnet/core/gro.c=654=static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)\n--\nnet/core/gro.c-682-\t\tskb_ext_reset(skb);\nnet/core/gro.c:683:\t\tnf_reset_ct(skb);\nnet/core/gro.c-684-\t\tskb-\u003eslow_gro = 0;\n--\nnet/core/skbuff.c=1169=void skb_release_head_state(struct sk_buff *skb)\n--\nnet/core/skbuff.c-1187-\t}\nnet/core/skbuff.c:1188:\tnf_reset_ct(skb);\nnet/core/skbuff.c-1189-\tskb_ext_reset(skb);\n--\nnet/core/skbuff.c=1495=void napi_skb_free_stolen_head(struct sk_buff *skb)\n--\nnet/core/skbuff.c-1497-\tif (unlikely(skb-\u003eslow_gro)) {\nnet/core/skbuff.c:1498:\t\tnf_reset_ct(skb);\nnet/core/skbuff.c-1499-\t\tskb_dst_drop(skb);\n--\nnet/core/skbuff.c=6278=void skb_scrub_packet(struct sk_buff *skb, bool xnet)\n--\nnet/core/skbuff.c-6284-\tskb_ext_reset(skb);\nnet/core/skbuff.c:6285:\tnf_reset_ct(skb);\nnet/core/skbuff.c-6286-\tnf_reset_trace(skb);\n--\nnet/ipv4/inet_fragment.c=433=int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,\n--\nnet/ipv4/inet_fragment.c-492-\tif (offset)\nnet/ipv4/inet_fragment.c:493:\t\tnf_reset_ct(skb);\nnet/ipv4/inet_fragment.c-494-\n--\nnet/ipv4/ip_input.c=189=void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int protocol)\n--\nnet/ipv4/ip_input.c-204-\t\t\t}\nnet/ipv4/ip_input.c:205:\t\t\tnf_reset_ct(skb);\nnet/ipv4/ip_input.c-206-\t\t}\n--\nnet/ipv4/ipmr.c=1838=static void ip_encap(struct net *net, struct sk_buff *skb,\n--\nnet/ipv4/ipmr.c-1861-\tmemset(\u0026(IPCB(skb)-\u003eopt), 0, sizeof(IPCB(skb)-\u003eopt));\nnet/ipv4/ipmr.c:1862:\tnf_reset_ct(skb);\nnet/ipv4/ipmr.c-1863-}\n--\nnet/ipv4/ipmr.c=2189=int ip_mr_input(struct sk_buff *skb)\n--\nnet/ipv4/ipmr.c-2238-\t\t\tif (mroute_sk) {\nnet/ipv4/ipmr.c:2239:\t\t\t\tnf_reset_ct(skb);\nnet/ipv4/ipmr.c-2240-\t\t\t\traw_rcv(mroute_sk, skb);\n--\nnet/ipv4/netfilter/nf_dup_ipv4.c=51=void nf_dup_ipv4(struct net *net, struct sk_buff *skb, unsigned int hooknum,\n--\nnet/ipv4/netfilter/nf_dup_ipv4.c-69-\t/* Avoid counting cloned packets towards the original connection. */\nnet/ipv4/netfilter/nf_dup_ipv4.c:70:\tnf_reset_ct(skb);\nnet/ipv4/netfilter/nf_dup_ipv4.c-71-\tnf_ct_set(skb, NULL, IP_CT_UNTRACKED);\n--\nnet/ipv4/raw.c=318=int raw_rcv(struct sock *sk, struct sk_buff *skb)\n--\nnet/ipv4/raw.c-324-\t}\nnet/ipv4/raw.c:325:\tnf_reset_ct(skb);\nnet/ipv4/raw.c-326-\n--\nnet/ipv4/tcp_ipv4.c=2070=int tcp_v4_rcv(struct sk_buff *skb)\n--\nnet/ipv4/tcp_ipv4.c-2182-\t\t}\nnet/ipv4/tcp_ipv4.c:2183:\t\tnf_reset_ct(skb);\nnet/ipv4/tcp_ipv4.c-2184-\t\tif (nsk == sk) {\n--\nnet/ipv4/tcp_ipv4.c-2223-\nnet/ipv4/tcp_ipv4.c:2224:\tnf_reset_ct(skb);\nnet/ipv4/tcp_ipv4.c-2225-\n--\nnet/ipv4/udp.c=2349=static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)\n--\nnet/ipv4/udp.c-2361-\t}\nnet/ipv4/udp.c:2362:\tnf_reset_ct(skb);\nnet/ipv4/udp.c-2363-\n--\nnet/ipv4/udp.c=2588=int udp_rcv(struct sk_buff *skb)\n--\nnet/ipv4/udp.c-2654-\t\tgoto drop;\nnet/ipv4/udp.c:2655:\tnf_reset_ct(skb);\nnet/ipv4/udp.c-2656-\n--\nnet/ipv6/ip6_input.c=403=void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr,\n--\nnet/ipv6/ip6_input.c-475-\t\t\t}\nnet/ipv6/ip6_input.c:476:\t\t\tnf_reset_ct(skb);\nnet/ipv6/ip6_input.c-477-\t\t}\n--\nnet/ipv6/netfilter/nf_dup_ipv6.c=47=void nf_dup_ipv6(struct net *net, struct sk_buff *skb, unsigned int hooknum,\n--\nnet/ipv6/netfilter/nf_dup_ipv6.c-57-#if IS_ENABLED(CONFIG_NF_CONNTRACK)\nnet/ipv6/netfilter/nf_dup_ipv6.c:58:\tnf_reset_ct(skb);\nnet/ipv6/netfilter/nf_dup_ipv6.c-59-\tnf_ct_set(skb, NULL, IP_CT_UNTRACKED);\n--\nnet/ipv6/raw.c=388=int rawv6_rcv(struct sock *sk, struct sk_buff *skb)\n--\nnet/ipv6/raw.c-397-\t}\nnet/ipv6/raw.c:398:\tnf_reset_ct(skb);\nnet/ipv6/raw.c-399-\n--\nnet/ipv6/seg6_iptunnel.c=396=static int seg6_do_srh(struct sk_buff *skb, struct dst_entry *cache_dst)\n--\nnet/ipv6/seg6_iptunnel.c-469-\tskb_set_transport_header(skb, sizeof(struct ipv6hdr));\nnet/ipv6/seg6_iptunnel.c:470:\tnf_reset_ct(skb);\nnet/ipv6/seg6_iptunnel.c-471-\n--\nnet/ipv6/seg6_local.c=929=static int input_action_end_dx6(struct sk_buff *skb,\n--\nnet/ipv6/seg6_local.c-942-\tskb_set_transport_header(skb, sizeof(struct ipv6hdr));\nnet/ipv6/seg6_local.c:943:\tnf_reset_ct(skb);\nnet/ipv6/seg6_local.c-944-\n--\nnet/ipv6/seg6_local.c=982=static int input_action_end_dx4(struct sk_buff *skb,\n--\nnet/ipv6/seg6_local.c-992-\tskb_set_transport_header(skb, sizeof(struct iphdr));\nnet/ipv6/seg6_local.c:993:\tnf_reset_ct(skb);\nnet/ipv6/seg6_local.c-994-\n--\nnet/ipv6/seg6_local.c=1131=static struct sk_buff *end_dt_vrf_core(struct sk_buff *skb,\n--\nnet/ipv6/seg6_local.c-1167-\tskb_set_transport_header(skb, hdrlen);\nnet/ipv6/seg6_local.c:1168:\tnf_reset_ct(skb);\nnet/ipv6/seg6_local.c-1169-\n--\nnet/ipv6/tcp_ipv6.c=1730=INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)\n--\nnet/ipv6/tcp_ipv6.c-1838-\t\t}\nnet/ipv6/tcp_ipv6.c:1839:\t\tnf_reset_ct(skb);\nnet/ipv6/tcp_ipv6.c-1840-\t\tif (nsk == sk) {\n--\nnet/ipv6/tcp_ipv6.c-1879-\nnet/ipv6/tcp_ipv6.c:1880:\tnf_reset_ct(skb);\nnet/ipv6/tcp_ipv6.c-1881-\n--\nnet/ipv6/udp.c=806=static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)\n--\nnet/ipv6/udp.c-815-\t}\nnet/ipv6/udp.c:816:\tnf_reset_ct(skb);\nnet/ipv6/udp.c-817-\n--\nnet/ipv6/udp.c=1067=INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)\n--\nnet/ipv6/udp.c-1152-\t\tgoto discard;\nnet/ipv6/udp.c:1153:\tnf_reset_ct(skb);\nnet/ipv6/udp.c-1154-\n--\nnet/l2tp/l2tp_core.c=1225=static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, unsigned int *len)\n--\nnet/l2tp/l2tp_core.c-1254-\nnet/l2tp/l2tp_core.c:1255:\tnf_reset_ct(skb);\nnet/l2tp/l2tp_core.c-1256-\n--\nnet/l2tp/l2tp_eth.c=107=static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)\n--\nnet/l2tp/l2tp_eth.c-123-\tskb_dst_drop(skb);\nnet/l2tp/l2tp_eth.c:124:\tnf_reset_ct(skb);\nnet/l2tp/l2tp_eth.c-125-\n--\nnet/l2tp/l2tp_ip.c=125=static int l2tp_ip_recv(struct sk_buff *skb)\n--\nnet/l2tp/l2tp_ip.c-197-\nnet/l2tp/l2tp_ip.c:198:\tnf_reset_ct(skb);\nnet/l2tp/l2tp_ip.c-199-\n--\nnet/l2tp/l2tp_ip6.c=135=static int l2tp_ip6_recv(struct sk_buff *skb)\n--\nnet/l2tp/l2tp_ip6.c-207-\nnet/l2tp/l2tp_ip6.c:208:\tnf_reset_ct(skb);\nnet/l2tp/l2tp_ip6.c-209-\n--\nnet/netfilter/ipvs/ip_vs_xmit.c=633=static inline int ip_vs_tunnel_xmit_prepare(struct sk_buff *skb,\n--\nnet/netfilter/ipvs/ip_vs_xmit.c-641-\tif (ret == NF_ACCEPT) {\nnet/netfilter/ipvs/ip_vs_xmit.c:642:\t\tnf_reset_ct(skb);\nnet/netfilter/ipvs/ip_vs_xmit.c-643-\t\tskb_forward_csum(skb);\n--\nnet/openvswitch/vport-internal_dev.c=186=static int internal_dev_recv(struct sk_buff *skb)\n--\nnet/openvswitch/vport-internal_dev.c-196-\tskb_dst_drop(skb);\nnet/openvswitch/vport-internal_dev.c:197:\tnf_reset_ct(skb);\nnet/openvswitch/vport-internal_dev.c-198-\n--\nnet/packet/af_packet.c=1869=static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,\n--\nnet/packet/af_packet.c-1906-\t/* drop conntrack reference */\nnet/packet/af_packet.c:1907:\tnf_reset_ct(skb);\nnet/packet/af_packet.c-1908-\n--\nnet/packet/af_packet.c=2133=static int packet_rcv(struct sk_buff *skb, struct net_device *dev,\n--\nnet/packet/af_packet.c-2219-\t/* drop conntrack reference */\nnet/packet/af_packet.c:2220:\tnf_reset_ct(skb);\nnet/packet/af_packet.c-2221-\n--\nnet/sched/act_mirred.c=254=static int tcf_mirred_to_dev(struct sk_buff *skb, struct tcf_mirred *m,\n--\nnet/sched/act_mirred.c-300-\t/* All mirred/redirected skbs should clear previous ct info */\nnet/sched/act_mirred.c:301:\tnf_reset_ct(skb_to_send);\nnet/sched/act_mirred.c-302-\tif (want_ingress \u0026\u0026 !at_ingress) /* drop dst for egress -\u003e ingress */\n--\nnet/sched/act_nat.c=115=TC_INDIRECT_SCOPE int tcf_nat_act(struct sk_buff *skb,\n--\nnet/sched/act_nat.c-259-out:\nnet/sched/act_nat.c:260:\tnf_reset_ct(skb);\nnet/sched/act_nat.c-261-\treturn action;\n--\nnet/sched/act_pedit.c=380=TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,\n--\nnet/sched/act_pedit.c-511-\tif (l3_l4_changed)\nnet/sched/act_pedit.c:512:\t\tnf_reset_ct(skb);\nnet/sched/act_pedit.c-513-\n--\nnet/sctp/input.c=88=int sctp_rcv(struct sk_buff *skb)\n--\nnet/sctp/input.c-190-\t\tgoto discard_release;\nnet/sctp/input.c:191:\tnf_reset_ct(skb);\nnet/sctp/input.c-192-\n--\nnet/xfrm/xfrm_input.c=466=int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)\n--\nnet/xfrm/xfrm_input.c-736-\nnet/xfrm/xfrm_input.c:737:\tnf_reset_ct(skb);\nnet/xfrm/xfrm_input.c-738-\n--\nnet/xfrm/xfrm_interface_core.c=293=static void xfrmi_scrub_packet(struct sk_buff *skb, bool xnet)\n--\nnet/xfrm/xfrm_interface_core.c-299-\tskb_dst_drop(skb);\nnet/xfrm/xfrm_interface_core.c:300:\tnf_reset_ct(skb);\nnet/xfrm/xfrm_interface_core.c-301-\tnf_reset_trace(skb);\n--\nnet/xfrm/xfrm_output.c=593=int xfrm_output_resume(struct sock *sk, struct sk_buff *skb, int err)\n--\nnet/xfrm/xfrm_output.c-597-\twhile (likely((err = xfrm_output_one(skb, err)) == 0)) {\nnet/xfrm/xfrm_output.c:598:\t\tnf_reset_ct(skb);\nnet/xfrm/xfrm_output.c-599-\n--\nnet/xfrm/xfrm_output.c=622=static int xfrm_dev_direct_output(struct sock *sk, struct xfrm_state *x,\n--\nnet/xfrm/xfrm_output.c-635-\tskb_dst_set(skb, dst);\nnet/xfrm/xfrm_output.c:636:\tnf_reset_ct(skb);\nnet/xfrm/xfrm_output.c-637-\n--\nnet/xfrm/xfrm_policy.c=2890=static void xfrm_policy_queue_process(struct timer_list *t)\n--\nnet/xfrm/xfrm_policy.c-2959-\nnet/xfrm/xfrm_policy.c:2960:\t\tnf_reset_ct(skb);\nnet/xfrm/xfrm_policy.c-2961-\t\tskb_dst_drop(skb);\n"
}

gemini-3.1-pro-preview

null

null

							input: 19704
							output: 20
							thoughts: 247
						

**My Analysis of the Patch**

Okay, so this patch is touching `nf_reset_ct`, which I see is defined as a static inline function within `include/linux/skbuff.h`. Good, so it's a simple function to reset connection tracking information. It's not conditional on any specific kernel configuration, which simplifies things. However, it seems this is being used in the context of traffic control, given the patch is modifying `tcf_nat_act` and `tcf_pedit_act`.

My immediate focus, therefore, shifts to those two functions. I'll need to examine `net/sched/act_nat.c` and `net/sched/act_pedit.c` to understand how `nf_reset_ct` is being incorporated and the implications of this change.

Now, let's consider the relevant kernel configurations. From what I can see so far, we're likely dealing with `NET_SCHED`, `NET_CLS_ACT`, `NET_ACT_NAT`, and `NET_ACT_PEDIT`. I need to confirm if there are any other related configs in this area. Specifically, `NET_ACT_NAT` and `NET_ACT_PEDIT` are dependent on `NET_CLS_ACT`, which, in turn, depends on `NET_SCHED`. So we have a clear dependency chain here: `NET_SCHED` -> `NET_CLS_ACT` -> (`NET_ACT_NAT`, `NET_ACT_PEDIT`). I'll double check the `net/sched/Kconfig` file again to confirm my understanding of the dependencies.

{
  "Expression": "menuconfig NET_SCHED"
}

{
  "Output": "net/sched/Kconfig-5-\nnet/sched/Kconfig:6:menuconfig NET_SCHED\nnet/sched/Kconfig-7-\tbool \"QoS and/or fair queueing\"\n"
}

gemini-3.1-pro-preview

null

null

							input: 20380
							output: 34
							thoughts: 72
						

**My Configuration Check**

Okay, so I'm pretty sure `NET_SCHED` is the primary menuconfig I need to be looking at. Right, confirmed. Now, to make sure this is all set up, the core configs I'm enabling here are `NET_SCHED`, `NET_CLS_ACT`, `NET_ACT_NAT`, and `NET_ACT_PEDIT`. Those should give me what I need.

Just to be absolutely certain, let me quickly double-check that `NET_ACT_NAT` doesn't introduce any hidden dependencies that I'm overlooking. No point in making assumptions, especially when dealing with this level of configuration. Better safe than sorry.

{
  "File": "net/sched/Kconfig",
  "FirstLine": 760,
  "LineCount": 20
}

{
  "Contents": " 760:\t\n 761:\t\t  To compile this code as a module, choose M here: the\n 762:\t\t  module will be called act_sample.\n 763:\t\n 764:\tconfig NET_ACT_NAT\n 765:\t\ttristate \"Stateless NAT\"\n 766:\t\tdepends on NET_CLS_ACT\n 767:\t\thelp\n 768:\t\t  Say Y here to do stateless NAT on IPv4 packets.  You should use\n 769:\t\t  netfilter for NAT unless you know what you are doing.\n 770:\t\n 771:\t\t  To compile this code as a module, choose M here: the\n 772:\t\t  module will be called act_nat.\n 773:\t\n 774:\tconfig NET_ACT_PEDIT\n 775:\t\ttristate \"Packet Editing\"\n 776:\t\tdepends on NET_CLS_ACT\n 777:\t\thelp\n 778:\t\t  Say Y here if you want to mangle the content of packets.\n 779:\t\n"
}

gemini-3.1-pro-preview

null

null

							input: 20921
							output: 20
							thoughts: 92
						

**Focusing on the Core Changes**

Okay, so there are no hidden dependencies here, that's good. My primary focus needs to be on these specific functions. The patch documentation clearly indicates that the changes are isolated to `tcf_nat_act` and `tcf_pedit_act`. Therefore, my `FocusSymbols` variable, or whatever equivalent I'm using, needs to be set to those two functions specifically. `tcf_nat_act` and `tcf_pedit_act`. Now, I just need to verify whether these are exported symbols or defined as static functions within the kernel module. I need to know the scope of their use.

{
  "Expression": "tcf_nat_act"
}

{
  "Output": "include/net/tc_wrapper.h=36=TC_INDIRECT_ACTION_DECLARE(tcf_mpls_act);\ninclude/net/tc_wrapper.h:37:TC_INDIRECT_ACTION_DECLARE(tcf_nat_act);\ninclude/net/tc_wrapper.h-38-TC_INDIRECT_ACTION_DECLARE(tcf_pedit_act);\n--\ninclude/net/tc_wrapper.h=47=static inline int tc_act(struct sk_buff *skb, const struct tc_action *a,\n--\ninclude/net/tc_wrapper.h-105-#if IS_BUILTIN(CONFIG_NET_ACT_NAT)\ninclude/net/tc_wrapper.h:106:\tif (a-\u003eops-\u003eact == tcf_nat_act)\ninclude/net/tc_wrapper.h:107:\t\treturn tcf_nat_act(skb, a, res);\ninclude/net/tc_wrapper.h-108-#endif\n--\nnet/sched/act_nat.c=35=static int tcf_nat_init(struct net *net, struct nlattr *nla, struct nlattr *est,\n--\nnet/sched/act_nat.c-114-\nnet/sched/act_nat.c:115:TC_INDIRECT_SCOPE int tcf_nat_act(struct sk_buff *skb,\nnet/sched/act_nat.c-116-\t\t\t\t  const struct tc_action *a,\n--\nnet/sched/act_nat.c=317=static struct tc_action_ops act_nat_ops = {\n--\nnet/sched/act_nat.c-320-\t.owner\t\t=\tTHIS_MODULE,\nnet/sched/act_nat.c:321:\t.act\t\t=\ttcf_nat_act,\nnet/sched/act_nat.c-322-\t.dump\t\t=\ttcf_nat_dump,\n"
}

gemini-3.1-pro-preview

null

null

							input: 21664
							output: 21
							thoughts: 53
						

Okay, here's my interpretation of these thoughts, formatted as you requested:

**Analyzing Variable Scope**

Alright, so we're looking at these variables, specifically `TC_INDIRECT_SCOPE int` types. That means these integers aren't static; they have some sort of dynamic or indirect scope. It's a clue, potentially, about how they're used and how their values are managed, which is important to consider in the overall code flow.

Now, `tcf_pedit_act` is also declared with the same indirect scope. This means it has similar characteristics in terms of lifetime and accessibility. Given that both `TC_INDIRECT_SCOPE int` and `tcf_pedit_act` share the same properties, a deeper look into `tcf_pedit_act` is probably warranted. I need to understand its behavior and how its value is set and used in relation to other pieces of the code. Let's dig into that and see what we can find.

{
  "Expression": "tcf_pedit_act"
}

{
  "Output": "include/net/tc_wrapper.h=37=TC_INDIRECT_ACTION_DECLARE(tcf_nat_act);\ninclude/net/tc_wrapper.h:38:TC_INDIRECT_ACTION_DECLARE(tcf_pedit_act);\ninclude/net/tc_wrapper.h-39-TC_INDIRECT_ACTION_DECLARE(tcf_police_act);\n--\ninclude/net/tc_wrapper.h=47=static inline int tc_act(struct sk_buff *skb, const struct tc_action *a,\n--\ninclude/net/tc_wrapper.h-61-#if IS_BUILTIN(CONFIG_NET_ACT_PEDIT)\ninclude/net/tc_wrapper.h:62:\tif (a-\u003eops-\u003eact == tcf_pedit_act)\ninclude/net/tc_wrapper.h:63:\t\treturn tcf_pedit_act(skb, a, res);\ninclude/net/tc_wrapper.h-64-#endif\n--\nnet/sched/act_pedit.c=350=static int pedit_skb_hdr_offset(struct sk_buff *skb,\n--\nnet/sched/act_pedit.c-379-\nnet/sched/act_pedit.c:380:TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,\nnet/sched/act_pedit.c-381-\t\t\t\t    const struct tc_action *a,\n--\nnet/sched/act_pedit.c=648=static struct tc_action_ops act_pedit_ops = {\n--\nnet/sched/act_pedit.c-651-\t.owner\t\t=\tTHIS_MODULE,\nnet/sched/act_pedit.c:652:\t.act\t\t=\ttcf_pedit_act,\nnet/sched/act_pedit.c-653-\t.stats_update\t=\ttcf_pedit_stats_update,\n"
}

gemini-3.1-pro-preview

null

null

							input: 22447
							output: 149
							thoughts: 154
						

**My Fuzzing Assessment**

Okay, so I've just analyzed this patch. From a fuzzing perspective, the changes are definitely *functional* and, importantly, *reachable*. The verdict is clear: WorthFuzzing=true.

Specifically, we're looking at changes involving the network scheduling actions - NAT and pedit - as the configs `NET_SCHED`, `NET_CLS_ACT`, `NET_ACT_NAT`, and `NET_ACT_PEDIT` indicate. The key symbols that capture my attention are `tcf_nat_act` and `tcf_pedit_act`.

The core of the change lies in adding `nf_reset_ct(skb)` to these actions when L3/L4 headers are modified. This is a pretty significant operational modification within the NAT and pedit actions. And, as we know, both NAT and pedit are triggered through traffic control (tc) commands, meaning these functions are definitely accessible. This is a perfect scenario for injecting crafted packets to trigger this modified behavior and discover potential vulnerabilities.

Let's log this change as set-results.

{
  "EnableConfigs": [
    "NET_SCHED",
    "NET_CLS_ACT",
    "NET_ACT_NAT",
    "NET_ACT_PEDIT"
  ],
  "FocusSymbols": [
    "tcf_nat_act",
    "tcf_pedit_act"
  ],
  "Reasoning": "The patch adds `nf_reset_ct(skb)` to `tcf_nat_act` and `tcf_pedit_act` when L3/L4 headers are modified. This is a functional change in the network scheduling actions (NAT and pedit) which are reachable via traffic control (tc) commands.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "NET_SCHED",
    "NET_CLS_ACT",
    "NET_ACT_NAT",
    "NET_ACT_PEDIT"
  ],
  "FocusSymbols": [
    "tcf_nat_act",
    "tcf_pedit_act"
  ],
  "Reasoning": "The patch adds `nf_reset_ct(skb)` to `tcf_nat_act` and `tcf_pedit_act` when L3/L4 headers are modified. This is a functional change in the network scheduling actions (NAT and pedit) which are reachable via traffic control (tc) commands.",
  "WorthFuzzing": true
}

{
  "WorthFuzzing": true
}

null

best-expensive

null

{
  "KMSANReasoning": "The patch fixes conntrack state tracking when packets are modified by tc actions (NAT and pedit). It does so by calling `nf_reset_ct(skb)` to clear the conntrack state if L3/L4 headers are modified. This change only affects packet metadata (skb-\u003enfct) and does not introduce any new data structures, allocations, or data copied to user space. There is no risk of uninitialized memory usage or info-leaks. Standard KASAN and other bug detectors are sufficient to catch any potential memory corruption or use-after-free bugs related to skb manipulation.",
  "NeedsKMSAN": false
}

You are an expert Linux kernel security engineer specializing in kernel memory
error detectors (KASAN and KMSAN). Your job is to review the provided patch series and
determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer)
fuzzing session in addition to standard KASAN fuzzing.

CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN:
- Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable
  a comprehensive suite of debugging tools and sanitizers, including KASAN
  (out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP
  (locking bugs and deadlocks), UB-sanitizers, and memory corruption checks.
- KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap,
  or page allocations) and kernel-to-user memory info-leaks.

Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN,
LOCKDEP, OR OTHER STANDARD BUG DETECTORS.
A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY
set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks
that are detected ONLY by KMSAN.

Look holistically at the patch series and surrounding code. Even if no direct
uninitialized field accesses or new buffer allocations are added in the diff itself,
a patch may alter control flow, bounds checking, or data length calculations in ways
that change how the rest of the code operates on existing buffers (e.g. allowing
uninitialized stack/heap memory to be read, copied to user space, or used in control
flow). Do not hesitate to use your code access tools to inspect the surrounding code,
called functions, and callers.

Set NeedsKMSAN=true ONLY IF the patch introduces or modifies:
1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb
   attributes, ioctl output arguments, socket options, or BPF buffers) where fields
   or structure padding might not be fully initialized/zeroed.
2. Conditional logic or branching that depends on potentially uninitialized variables
   or struct fields.
3. Allocation or initialization of complex data structures where uninitialized fields
   could be read later in reachable code paths.
4. Bounds checks, lengths, or logic in a way that allows surrounding code to access
   uninitialized bytes of existing buffers.

Set NeedsKMSAN=false IF:
- The code changes primarily risk out-of-bounds access, array overflows, NULL pointer
  dereferences, locking deadlocks, or use-after-free bugs (these are already caught
  by KASAN, LOCKDEP, or standard bug detectors).
- All stack/heap structures touched or introduced by the patch are fully zeroed
  or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied.
- The patch does not introduce any risk of uninitialized memory usage or info-leaks.

Use your code access tools to inspect the surrounding code if necessary, then provide
detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch.
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 a9cfd7688dcd354428d5c03c39a1ad02bb31aaf7
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Aug 19 21:07:50 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/sched/act_nat.c b/net/sched/act_nat.c
index abb332dee836d..0c3d3b89d3499 100644
--- a/net/sched/act_nat.c
+++ b/net/sched/act_nat.c
@@ -257,6 +257,7 @@ TC_INDIRECT_SCOPE int tcf_nat_act(struct sk_buff *skb,
 	}
 
 out:
+	nf_reset_ct(skb);
 	return action;
 
 drop:
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index d4d47a9921f45..b079257c2b7b6 100644
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -386,6 +386,7 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 	struct tcf_pedit *p = to_pedit(a);
 	struct tcf_pedit_key_ex *tkey_ex;
 	struct tcf_pedit_parms *parms;
+	bool l3_l4_changed = false;
 	struct tc_pedit_key *tkey;
 	int i;
 
@@ -398,7 +399,7 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 	tkey_ex = parms->tcfp_keys_ex;
 
 	for (i = parms->tcfp_nkeys; i > 0; i--, tkey++) {
-		int write_offset, write_len;
+		int write_offset, write_len, nw_offset;
 		int offset = tkey->off;
 		int hoffset = 0;
 		u32 cur_val, val;
@@ -418,6 +419,8 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 			goto bad;
 		}
 
+		nw_offset = skb_network_offset(skb);
+
 		if (tkey->offmask) {
 			u8 *d, _d;
 			int at_offset;
@@ -485,6 +488,19 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 		}
 
 		put_unaligned((cur_val & tkey->mask) ^ val, ptr);
+
+		/* Track if L3 or L4 headers were modified:
+		 * - Direct L3/L4 header types
+		 * - ETH header type with offset/length reaching into L3/L4
+		 */
+		if (htype == TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK ||
+		    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_IP4 ||
+		    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_IP6 ||
+		    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_TCP ||
+		    htype == TCA_PEDIT_KEY_EX_HDR_TYPE_UDP ||
+		    (htype == TCA_PEDIT_KEY_EX_HDR_TYPE_ETH &&
+		     write_offset + (int)sizeof(*ptr) > nw_offset))
+			l3_l4_changed = true;
 	}
 
 	goto done;
@@ -492,6 +508,9 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 bad:
 	tcf_action_inc_overlimit_qstats(&p->common);
 done:
+	if (l3_l4_changed)
+		nf_reset_ct(skb);
+
 	return parms->action;
 }
 
diff --git a/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json b/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json
index 8ab48def89b6a..18a7737483580 100644
--- a/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json
+++ b/tools/testing/selftests/tc-testing/tc-tests/actions/ct.json
@@ -742,5 +742,173 @@
         "teardown": [
             "$TC qdisc del dev $DEV1 clsact"
         ]
+    },
+    {
+        "id": "c2a9",
+        "name": "Verify conntrack reset after pedit modifies IP protocol",
+        "category": [
+            "actions",
+            "ct",
+            "pedit",
+            "scapy"
+        ],
+        "plugins": {
+            "requires": [
+                "nsPlugin",
+                "scapyPlugin"
+            ]
+        },
+        "setup": [
+            [
+                "$TC qdisc del dev $DEV1 ingress",
+                0,
+                1,
+                2,
+                255
+            ],
+            "iptables -t raw -F",
+            "iptables -t raw -A PREROUTING -i $DEV1 -p icmp -m conntrack --ctstate INVALID -j DROP",
+            "$TC qdisc add dev $DEV1 ingress"
+        ],
+        "cmdUnderTest": "$TC filter add dev $DEV1 ingress protocol ip prio 1 flower action ct commit pipe action pedit ex munge ip protocol set 1 pipe action csum ip4h continue",
+        "scapy": {
+            "iface": "$DEV0",
+            "count": 1,
+            "packet": "Ether(type=0x800)/IP(src='10.0.0.10',dst='10.0.0.20',proto=6)/TCP(sport=1234,dport=80,flags='S')"
+        },
+        "expExitCode": "0",
+        "verifyCmd": "iptables-save -c -t raw | grep 'ctstate INVALID'",
+        "matchPattern": "^\\[1:40\\]",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DEV1 ingress",
+            "iptables -t raw -F"
+        ]
+    },
+    {
+        "id": "d3b8",
+        "name": "Verify conntrack reset after TCP port modification",
+        "category": [
+            "actions",
+            "ct",
+            "pedit",
+            "scapy"
+        ],
+        "plugins": {
+            "requires": [
+                "nsPlugin",
+                "scapyPlugin"
+            ]
+        },
+        "setup": [
+            [
+                "$TC qdisc del dev $DEV1 ingress",
+                0,
+                1,
+                2,
+                255
+            ],
+            "iptables -t raw -F",
+            "iptables -t raw -A PREROUTING -i $DEV1 -p tcp -m conntrack --ctstate INVALID -j DROP",
+            "$TC qdisc add dev $DEV1 ingress"
+        ],
+        "cmdUnderTest": "$TC filter add dev $DEV1 ingress protocol ip prio 1 flower ip_proto tcp action ct commit pipe action pedit ex munge tcp sport set 9999 pipe",
+        "scapy": {
+            "iface": "$DEV0",
+            "count": 1,
+            "packet": "Ether(type=0x800)/IP(src='10.0.0.10',dst='10.0.0.20')/TCP(sport=1234,dport=80,flags='S')"
+        },
+        "expExitCode": "0",
+        "verifyCmd": "iptables-save -c -t raw | grep 'ctstate INVALID'",
+        "matchCount": "1",
+        "matchPattern": "^\\[1:40\\]",
+        "teardown": [
+            "$TC qdisc del dev $DEV1 ingress",
+            "iptables -t raw -F"
+        ]
+    },
+    {
+        "id": "a1b2",
+        "name": "Verify conntrack NOT reset when pedit modifies only MAC",
+        "category": [
+            "actions",
+            "ct",
+            "pedit",
+            "scapy"
+        ],
+        "plugins": {
+            "requires": [
+                "nsPlugin",
+                "scapyPlugin"
+            ]
+        },
+        "setup": [
+            [
+                "$TC qdisc del dev $DEV1 ingress",
+                0,
+                1,
+                2,
+                255
+            ],
+            "iptables -t raw -F",
+            "iptables -t raw -A PREROUTING -i $DEV1 -p icmp -m conntrack --ctstate NEW -j DROP",
+            "$TC qdisc add dev $DEV1 ingress"
+        ],
+        "cmdUnderTest": "$TC filter add dev $DEV1 ingress protocol ip prio 1 flower action ct commit pipe action pedit ex munge eth src set 11:22:33:44:55:66 pipe",
+        "scapy": {
+            "iface": "$DEV0",
+            "count": 1,
+            "packet": "Ether(src='aa:bb:cc:dd:ee:ff',type=0x800)/IP(src='10.0.0.11',dst='10.0.0.21')/ICMP()"
+        },
+        "expExitCode": "0",
+        "verifyCmd": "iptables-save -c -t raw | grep 'ctstate NEW'",
+        "matchPattern": "^\\[1:28\\]",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DEV1 ingress",
+            "iptables -t raw -F"
+        ]
+    },
+    {
+        "id": "b7f4",
+        "name": "Verify conntrack reset when ETH write extends into IP layer",
+        "category": [
+            "actions",
+            "ct",
+            "pedit",
+            "scapy"
+        ],
+        "plugins": {
+            "requires": [
+                "nsPlugin",
+                "scapyPlugin"
+            ]
+        },
+        "setup": [
+            [
+                "$TC qdisc del dev $DEV1 ingress",
+                0,
+                1,
+                2,
+                255
+            ],
+            "iptables -t raw -F",
+            "iptables -t raw -A PREROUTING -i $DEV1 -m conntrack --ctstate INVALID -j DROP",
+            "$TC qdisc add dev $DEV1 ingress"
+        ],
+        "cmdUnderTest": "$TC filter add dev $DEV1 ingress protocol ip prio 1 flower action ct commit pipe action pedit ex munge offset 12 u32 set 0x08004500 pipe csum ip4h continue",
+        "scapy": {
+            "iface": "$DEV0",
+            "count": 1,
+            "packet": "Ether(type=0x800)/IP(src='10.0.0.13',dst='10.0.0.23')/ICMP()"
+        },
+        "expExitCode": "0",
+        "verifyCmd": "iptables-save -t raw -c | grep 'ctstate INVALID'",
+        "matchPattern": "^\\[1:28\\]",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DEV1 ingress",
+            "iptables -t raw -F"
+        ]
     }
 ]
diff --git a/tools/testing/selftests/tc-testing/tdc.py b/tools/testing/selftests/tc-testing/tdc.py
index 511d66c36a2a0..19b8a1fd1c716 100755
--- a/tools/testing/selftests/tc-testing/tdc.py
+++ b/tools/testing/selftests/tc-testing/tdc.py
@@ -600,6 +600,18 @@ def mp_bins(alltests):
 
     return (serial, parallel)
 
+mp_pm = None
+mp_args = None
+
+def __mp_init__(pm, args):
+    """
+    This function is called once when each worker process starts.
+    It sets the global variables in the child process's memory space.
+    """
+    global mp_pm, mp_args
+    mp_pm = pm
+    mp_args = args
+
 def __mp_runner(tests):
     (_, tsr) = test_runner(mp_pm, mp_args, tests)
     return tsr._testsuite
@@ -615,14 +627,13 @@ def test_runner_mp(pm, args, alltests):
     print("Executing {} tests in parallel and {} in serial".format(len(parallel), len(serial)))
     print("Using {} batches and {} workers".format(len(batches), args.mp))
 
-    # We can't pickle these objects so workaround them
-    global mp_pm
-    mp_pm = pm
-
-    global mp_args
-    mp_args = args
-
-    with Pool(args.mp) as p:
+    # Use the 'initializer' to pass the unpickleable/shared objects
+    # to each worker process exactly once upon startup.
+    with Pool(
+        processes=args.mp,
+        initializer=__mp_init__,
+        initargs=(pm, args)
+    ) as p:
         pres = p.map(__mp_runner, batches)
 
     tsr = TestSuiteReport()

gemini-3.1-pro-preview

null

null

							input: 5394
							output: 154
							thoughts: 505
						

**Analyzing the Conntrack State Reset Patch**

Okay, so I've been looking over this patch. It focuses on `net/sched/act_nat.c` and `net/sched/act_pedit.c`, specifically. The core of the change involves calling `nf_reset_ct(skb)` in those actions. In the NAT action, it's a direct call before returning. For the pedit action, it's conditional, triggered if either L3 or L4 headers have been touched, based on checking `htype` and `write_offset`. They also updated some tests and fixed a multiprocessing issue in the testing scripts, which is always good to see.

My primary concern, as always with any kernel patch, is potential uninitialized memory issues. This is a crucial area and can lead to serious vulnerabilities. But, digging deeper, it seems pretty clear this patch is *not* introducing such risks. `nf_reset_ct(skb)` simply clears the conntrack state associated with the `skb`. It's essentially a reset.

There are no new structures, no new allocations, nothing being sent to userspace. It is just dealing with conntrack state changes. That's a good sign, so it should not introduce risks of uninitialized memory usage or info-leaks.

To be absolutely sure, I checked the definition of `nf_reset_ct` (it's either inline in `include/linux/skbuff.h` or within `include/net/netfilter/nf_conntrack.h`). It's a straightforward operation: it calls `nf_conntrack_put(skb->nfct)` and then sets `skb->nfct` to `NULL`. No fancy memory manipulation there; all operations involve structures already managed within the kernel.

Therefore, my conclusion is that this patch should *not* trigger a `NeedsKMSAN` flag. It is purely a logic fix for conntrack state and doesn't introduce any new memory safety concerns. I'm confident in saying that the standard KASAN and other bug detectors should be sufficient to catch any potential memory corruption or use-after-free bugs related to skb manipulation. I will use the `set-results` tool to mark the patch accordingly.

{
  "KMSANReasoning": "The patch fixes conntrack state tracking when packets are modified by tc actions (NAT and pedit). It does so by calling `nf_reset_ct(skb)` to clear the conntrack state if L3/L4 headers are modified. This change only affects packet metadata (skb-\u003enfct) and does not introduce any new data structures, allocations, or data copied to user space. There is no risk of uninitialized memory usage or info-leaks. Standard KASAN and other bug detectors are sufficient to catch any potential memory corruption or use-after-free bugs related to skb manipulation.",
  "NeedsKMSAN": false
}

{
  "KMSANReasoning": "The patch fixes conntrack state tracking when packets are modified by tc actions (NAT and pedit). It does so by calling `nf_reset_ct(skb)` to clear the conntrack state if L3/L4 headers are modified. This change only affects packet metadata (skb-\u003enfct) and does not introduce any new data structures, allocations, or data copied to user space. There is no risk of uninitialized memory usage or info-leaks. Standard KASAN and other bug detectors are sufficient to catch any potential memory corruption or use-after-free bugs related to skb manipulation.",
  "NeedsKMSAN": false
}