AI Trajectory

null

{
  "EnableConfigs": [
    "TLS",
    "TLS_DEVICE",
    "BPF_STREAM_PARSER"
  ],
  "FocusSymbols": [
    "sock_dequeue_err_skb",
    "tls_rx_rec_wait",
    "tls_sw_recvmsg",
    "tls_sw_sendmsg",
    "tls_sw_sendmsg_locked",
    "tls_encrypt_done",
    "bpf_exec_tx_verdict",
    "tls_push_data",
    "tls_device_sendmsg",
    "strp_abort_strp",
    "sk_psock_backlog"
  ],
  "KMSANReasoning": "The patch addresses data races on `sk-\u003esk_err` by adding `READ_ONCE()` and `WRITE_ONCE()` annotations and refactoring error handling in TLS, strparser, and core skbuff routines.\n\nKMSAN is specifically designed to track and detect uninitialized memory reads and information leaks of uninitialized kernel memory to userspace. This patch does not introduce any uninitialized memory risks:\n1. No new stack or heap allocations, complex structs, or padding fields are introduced.\n2. The local helper variables introduced (`skerr`, `rc`) are explicitly initialized before evaluation.\n3. Socket structures and `sk-\u003esk_err` are fully initialized at socket creation time.\n4. No data copying to user space or length/bound calculations are modified in a manner that could expose uninitialized buffer contents.\n\nThe concurrency and data-race bugs targeted by this patch fall within the scope of KCSAN, and pointer/lifetime safety falls under KASAN. A dedicated KMSAN fuzzing session is not warranted.",
  "NeedsKMSAN": false,
  "Reasoning": "The patch alters socket error reporting and concurrency handling (READ_ONCE/WRITE_ONCE and sock_error() consumption) for sk-\u003esk_err across kTLS, socket error queue dequeueing, strparser, and psock. These changes affect reachable core networking and kTLS paths that can be exercised via user-space socket calls. Fuzzing is warranted to test for race conditions, unexpected error propagation, or state corruption.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit 81eb749005a44840efc46fa7f5abd086c7d9b464\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Fri Oct 16 07:13:18 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/include/linux/skmsg.h b/include/linux/skmsg.h\nindex d5e35f24738d5..52ce45f25f5a6 100644\n--- a/include/linux/skmsg.h\n+++ b/include/linux/skmsg.h\n@@ -429,7 +429,7 @@ static inline void sk_psock_report_error(struct sk_psock *psock, int err)\n {\n \tstruct sock *sk = psock-\u003esk;\n \n-\tsk-\u003esk_err = err;\n+\tWRITE_ONCE(sk-\u003esk_err, err);\n \tsk_error_report(sk);\n }\n \ndiff --git a/net/core/skbuff.c b/net/core/skbuff.c\nindex d56f4f0102f75..a6c9cf57bc3bf 100644\n--- a/net/core/skbuff.c\n+++ b/net/core/skbuff.c\n@@ -5539,12 +5539,13 @@ struct sk_buff *sock_dequeue_err_skb(struct sock *sk)\n \tif (skb \u0026\u0026 (skb_next = skb_peek(q))) {\n \t\ticmp_next = is_icmp_err_skb(skb_next);\n \t\tif (icmp_next)\n-\t\t\tsk-\u003esk_err = SKB_EXT_ERR(skb_next)-\u003eee.ee_errno;\n+\t\t\tWRITE_ONCE(sk-\u003esk_err,\n+\t\t\t\t   SKB_EXT_ERR(skb_next)-\u003eee.ee_errno);\n \t}\n \tspin_unlock_irqrestore(\u0026q-\u003elock, flags);\n \n \tif (is_icmp_err_skb(skb) \u0026\u0026 !icmp_next)\n-\t\tsk-\u003esk_err = 0;\n+\t\tWRITE_ONCE(sk-\u003esk_err, 0);\n \n \tif (skb_next)\n \t\tsk_error_report(sk);\ndiff --git a/net/strparser/strparser.c b/net/strparser/strparser.c\nindex 9c1559d7923f2..5f1da32b152fc 100644\n--- a/net/strparser/strparser.c\n+++ b/net/strparser/strparser.c\n@@ -56,7 +56,7 @@ static void strp_abort_strp(struct strparser *strp, int err)\n \tstrp-\u003eneed_bytes = 0;\n \n \t/* Report an error on the lower socket */\n-\tsk-\u003esk_err = -err;\n+\tWRITE_ONCE(sk-\u003esk_err, -err);\n \tsk_error_report(sk);\n }\n \ndiff --git a/net/tls/tls_device.c b/net/tls/tls_device.c\nindex f11d0528fc431..03ce83a9d4e9c 100644\n--- a/net/tls/tls_device.c\n+++ b/net/tls/tls_device.c\n@@ -444,8 +444,9 @@ static int tls_push_data(struct sock *sk,\n \tif ((flags \u0026 (MSG_MORE | MSG_EOR)) == (MSG_MORE | MSG_EOR))\n \t\treturn -EINVAL;\n \n-\tif (unlikely(sk-\u003esk_err))\n-\t\treturn -sk-\u003esk_err;\n+\trc = -READ_ONCE(sk-\u003esk_err);\n+\tif (unlikely(rc))\n+\t\treturn rc;\n \n \tflags |= MSG_SENDPAGE_DECRYPTED;\n \ttls_push_record_flags = flags | MSG_MORE;\ndiff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c\nindex 312e51270f293..4221b2ad3c1d3 100644\n--- a/net/tls/tls_sw.c\n+++ b/net/tls/tls_sw.c\n@@ -473,6 +473,7 @@ static void tls_encrypt_done(void *data, int err)\n \tstruct scatterlist *sge;\n \tstruct sk_msg *msg_en;\n \tstruct sock *sk;\n+\tint skerr;\n \n \tif (err == -EINPROGRESS) /* see the comment in tls_decrypt_done() */\n \t\treturn;\n@@ -488,13 +489,15 @@ static void tls_encrypt_done(void *data, int err)\n \tsge-\u003eoffset -= prot-\u003eprepend_size;\n \tsge-\u003elength += prot-\u003eprepend_size;\n \n+\tskerr = READ_ONCE(sk-\u003esk_err);\n+\n \t/* Check if error is previously set on socket */\n-\tif (err || sk-\u003esk_err) {\n+\tif (err || skerr) {\n \t\trec = NULL;\n \n \t\t/* If err is already set on socket, return the same code */\n-\t\tif (sk-\u003esk_err) {\n-\t\t\tctx-\u003easync_wait.err = -sk-\u003esk_err;\n+\t\tif (skerr) {\n+\t\t\tctx-\u003easync_wait.err = -skerr;\n \t\t} else {\n \t\t\tctx-\u003easync_wait.err = err;\n \t\t\ttls_err_abort(sk, err);\n@@ -701,13 +704,17 @@ static int tls_push_record(struct sock *sk, int flags,\n static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,\n \t\t\t       u8 record_type, ssize_t *copied, int flags)\n {\n+\tint skerr;\n \tint err;\n \n \terr = tls_push_record(sk, flags, record_type);\n-\tif (err \u0026\u0026 err != -EINPROGRESS \u0026\u0026 sk-\u003esk_err == EBADMSG) {\n-\t\t*copied -= sk_msg_free(sk, msg);\n-\t\ttls_free_open_rec(sk);\n-\t\terr = -sk-\u003esk_err;\n+\tif (err \u0026\u0026 err != -EINPROGRESS) {\n+\t\tskerr = READ_ONCE(sk-\u003esk_err);\n+\t\tif (skerr == EBADMSG) {\n+\t\t\t*copied -= sk_msg_free(sk, msg);\n+\t\t\ttls_free_open_rec(sk);\n+\t\t\terr = -skerr;\n+\t\t}\n \t}\n \treturn err;\n }\n@@ -800,10 +807,9 @@ static int tls_sw_sendmsg_locked(struct sock *sk, struct msghdr *msg,\n \t}\n \n \twhile (msg_data_left(msg)) {\n-\t\tif (sk-\u003esk_err) {\n-\t\t\tret = -sk-\u003esk_err;\n+\t\tret = -READ_ONCE(sk-\u003esk_err);\n+\t\tif (ret)\n \t\t\tgoto send_end;\n-\t\t}\n \n \t\tif (ctx-\u003eopen_rec)\n \t\t\trec = ctx-\u003eopen_rec;\n@@ -1098,6 +1104,7 @@ tls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)\n \tstruct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);\n \tDEFINE_WAIT_FUNC(wait, woken_wake_function);\n \tint ret = 0;\n+\tint skerr;\n \tlong timeo;\n \n \t/* a rekey is pending, let userspace deal with it */\n@@ -1107,10 +1114,14 @@ tls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)\n \ttimeo = sock_rcvtimeo(sk, nonblock);\n \n \twhile (!tls_strp_msg_ready(ctx)) {\n-\t\tif (sk-\u003esk_err) {\n-\t\t\tif (has_copied)\n-\t\t\t\treturn -READ_ONCE(sk-\u003esk_err);\n-\t\t\treturn sock_error(sk);\n+\t\tif (has_copied) {\n+\t\t\tskerr = READ_ONCE(sk-\u003esk_err);\n+\t\t\tif (skerr)\n+\t\t\t\treturn -skerr;\n+\t\t} else {\n+\t\t\tskerr = sock_error(sk);\n+\t\t\tif (skerr)\n+\t\t\t\treturn skerr;\n \t\t}\n \n \t\tif (ret \u003c 0)\n@@ -1132,10 +1143,14 @@ tls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)\n \t\t * sk_err here so a connection abort surfaces as the\n \t\t * actual error rather than a clean EOF.\n \t\t */\n-\t\tif (sk-\u003esk_err) {\n-\t\t\tif (has_copied)\n-\t\t\t\treturn -READ_ONCE(sk-\u003esk_err);\n-\t\t\treturn sock_error(sk);\n+\t\tif (has_copied) {\n+\t\t\tskerr = READ_ONCE(sk-\u003esk_err);\n+\t\t\tif (skerr)\n+\t\t\t\treturn -skerr;\n+\t\t} else {\n+\t\t\tskerr = sock_error(sk);\n+\t\t\tif (skerr)\n+\t\t\t\treturn skerr;\n \t\t}\n \t\tif (sk-\u003esk_shutdown \u0026 RCV_SHUTDOWN)\n \t\t\treturn 0;\n"
}

core

null

{
  "EnableConfigs": [
    "TLS",
    "TLS_DEVICE",
    "BPF_STREAM_PARSER"
  ],
  "FocusSymbols": [
    "sock_dequeue_err_skb",
    "tls_rx_rec_wait",
    "tls_sw_recvmsg",
    "tls_sw_sendmsg",
    "tls_sw_sendmsg_locked",
    "tls_encrypt_done",
    "bpf_exec_tx_verdict",
    "tls_push_data",
    "tls_device_sendmsg",
    "strp_abort_strp",
    "sk_psock_backlog"
  ],
  "Reasoning": "The patch alters socket error reporting and concurrency handling (READ_ONCE/WRITE_ONCE and sock_error() consumption) for sk-\u003esk_err across kTLS, socket error queue dequeueing, strparser, and psock. These changes affect reachable core networking and kTLS paths that can be exercised via user-space socket calls. Fuzzing is warranted to test for race conditions, unexpected error propagation, or state corruption.",
  "WorthFuzzing": true
}

You are an expert Linux kernel maintainer and security engineer.
Your job is to review a provided patch series and evaluate whether it warrants fuzzing with syzkaller.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on internal assumptions. You must actively use your code access
tools to inspect the actual source code, callers, and surrounding context.

================================================================================
1. CORE TRIAGE PHILOSOPHY
================================================================================
The goal of patch fuzzing is to discover crashes, regressions, exposed latent bugs,
and newly triggered assertions introduced by the patch series.

- REACHABILITY IS THE PRIMARY GATE:
  Fuzzing can only discover bugs in code that can actually execute in standard virtualized
  environments (GCE or QEMU, utilizing software-emulated devices like USB gadgets, netdev, tun/tap).
  If the modified code is structurally unreachable (see Section 2), it MUST NOT be fuzzed,
  regardless of whether it adds assertions or complex logic.

- DO NOT BLINDLY TRUST "NO FUNCTIONAL CHANGE" (NFCI) OR "REFACTORING" CLAIMS:
  Patch authors routinely label changes as "cleanups", "refactorings", or state
  "No functional change intended". Do NOT take these claims at face value.
  Code refactorings that rearrange logic, introduce helper functions, or alter state management
  in core subsystems frequently introduce subtle semantic shifts or uncover latent kernel bugs.
  If reachable executable code is modified or refactored, it MUST be fuzzed.

- NEW OR MODIFIED ASSERTIONS IN REACHABLE CODE MUST BE FUZZED:
  When a patch introduces or modifies runtime checks or assertions (e.g., WARN_ON*, VM_WARN_ON*,
  BUG_ON*, lockdep_assert*) in reachable code paths, it enforces new or stricter invariants.
  Even if the author believes the invariant always holds, fuzzing is essential to verify whether
  an unusual sequence of operations can violate it.

================================================================================
2. WHEN TO RETURN WorthFuzzing=false (NEGATIVE CRITERIA)
================================================================================
Return WorthFuzzing=false ONLY IF all modified code falls strictly into one or more of these categories:

- Non-kernel and non-executable changes:
  * Modifications to Documentation/, comments, or spelling fixes.
  * User-space directories, self-tests, samples, or scripts (e.g., tools/, samples/, scripts/, usr/)
    that do not affect the compiled kernel image (vmlinux) or kernel modules.
  * Purely decorative logging (e.g., message strings in pr_err, printk, dev_info) or tracepoints
    that do not alter control flow or data structures.
  * Build system or Kconfig changes that do not alter compiled C logic.
- Structurally unreachable hardware:
  * Vendor-specific PCIe switches, SmartNICs, or GPU drivers (e.g., mlxsw, pds_core, qed,
    ionic, amdgpu) requiring physical ASIC/PCIe cards not emulated in standard QEMU.
- Unreachable execution paths:
  * Driver teardown callbacks (.remove, .shutdown, pci_unregister_driver) executed only during
    physical PCI hot-unplug or manual sysfs driver unbinding.
  * Code paths exclusive to architectures other than the target architecture.

================================================================================
3. WHEN TO RETURN WorthFuzzing=true (POSITIVE CRITERIA)
================================================================================
Return WorthFuzzing=true whenever the patch touches reachable executable code, including:
- Core Subsystems:
  * Any logic modifications in memory management (mm/), synchronization/locking (kernel/locking/),
    BPF, scheduler, core networking, VFS, or syscall handling.
- Refactorings and Code Cleanups:
  * Any restructuring of reachable data structures, helper abstractions, or algorithm flows.
- Runtime Assertions and Defensive Checks:
  * Any introduction or alteration of assertions (WARN_ON*, VM_WARN_ON*, BUG_ON*, etc.) in reachable paths.
- Reachable Drivers and Protocols:
  * Drivers accessible via virtual buses (virtio, USB gadget, loopback, netlink, binder, sockets, etc.).

================================================================================
4. EXTRACTING FocusSymbols (PREVENTING DILUTION)
================================================================================
When WorthFuzzing=true, you must extract specific kernel functions into FocusSymbols to guide the fuzzer:

- AVOID UBIQUITOUS LIFECYCLE HOT-PATHS:
  Do NOT list generic, ubiquitous functions called by almost every program in the corpus
  (including, but not limited to: general memory allocators and deallocators, page fault
  and trap handlers, or core synchronization primitives; this is not an exhaustive list).
  Listing ubiquitous functions causes the fuzzer to classify thousands of unrelated tests as "focused",
  which severely dilutes fuzzing effort away from the actual changes.

- TARGET SPECIFIC FEATURE LOGIC AND ENTRYPOINTS:
  List functions that specifically implement the logic being added or altered, or direct API entrypoints
  for the subsystem feature under review.

- HANDLING STATIC INLINE FUNCTIONS IN HEADERS (.h):
  Compiler-inlined static functions (such as static inlines in mm/*.h or include/linux/*.h) lack
  distinct symbol addresses in vmlinux and cannot be targeted directly by symbol coverage filters.
  If the changes are primarily in static inline helpers, identify non-static, feature-specific caller
  functions in .c files that exercise them (avoiding ubiquitous lifecycle wrappers).

================================================================================
5. IDENTIFYING EnableConfigs
================================================================================
Identify any specific CONFIG_ options required to properly compile and reach the modified code:
- Inspect Kconfig files and #ifdef guards; do not make assumptions.
- Check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed.
- Strip any '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.

Target architecture: amd64

For your convenience, here is the diff of the changes:
commit 81eb749005a44840efc46fa7f5abd086c7d9b464
Author: syz-cluster <triage@syzkaller.com>
Date:   Fri Oct 16 07:13:18 2026 +0000

    syz-cluster: applied patch under review

diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index d5e35f24738d5..52ce45f25f5a6 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -429,7 +429,7 @@ static inline void sk_psock_report_error(struct sk_psock *psock, int err)
 {
 	struct sock *sk = psock->sk;
 
-	sk->sk_err = err;
+	WRITE_ONCE(sk->sk_err, err);
 	sk_error_report(sk);
 }
 
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index d56f4f0102f75..a6c9cf57bc3bf 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -5539,12 +5539,13 @@ struct sk_buff *sock_dequeue_err_skb(struct sock *sk)
 	if (skb && (skb_next = skb_peek(q))) {
 		icmp_next = is_icmp_err_skb(skb_next);
 		if (icmp_next)
-			sk->sk_err = SKB_EXT_ERR(skb_next)->ee.ee_errno;
+			WRITE_ONCE(sk->sk_err,
+				   SKB_EXT_ERR(skb_next)->ee.ee_errno);
 	}
 	spin_unlock_irqrestore(&q->lock, flags);
 
 	if (is_icmp_err_skb(skb) && !icmp_next)
-		sk->sk_err = 0;
+		WRITE_ONCE(sk->sk_err, 0);
 
 	if (skb_next)
 		sk_error_report(sk);
diff --git a/net/strparser/strparser.c b/net/strparser/strparser.c
index 9c1559d7923f2..5f1da32b152fc 100644
--- a/net/strparser/strparser.c
+++ b/net/strparser/strparser.c
@@ -56,7 +56,7 @@ static void strp_abort_strp(struct strparser *strp, int err)
 	strp->need_bytes = 0;
 
 	/* Report an error on the lower socket */
-	sk->sk_err = -err;
+	WRITE_ONCE(sk->sk_err, -err);
 	sk_error_report(sk);
 }
 
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index f11d0528fc431..03ce83a9d4e9c 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -444,8 +444,9 @@ static int tls_push_data(struct sock *sk,
 	if ((flags & (MSG_MORE | MSG_EOR)) == (MSG_MORE | MSG_EOR))
 		return -EINVAL;
 
-	if (unlikely(sk->sk_err))
-		return -sk->sk_err;
+	rc = -READ_ONCE(sk->sk_err);
+	if (unlikely(rc))
+		return rc;
 
 	flags |= MSG_SENDPAGE_DECRYPTED;
 	tls_push_record_flags = flags | MSG_MORE;
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 312e51270f293..4221b2ad3c1d3 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -473,6 +473,7 @@ static void tls_encrypt_done(void *data, int err)
 	struct scatterlist *sge;
 	struct sk_msg *msg_en;
 	struct sock *sk;
+	int skerr;
 
 	if (err == -EINPROGRESS) /* see the comment in tls_decrypt_done() */
 		return;
@@ -488,13 +489,15 @@ static void tls_encrypt_done(void *data, int err)
 	sge->offset -= prot->prepend_size;
 	sge->length += prot->prepend_size;
 
+	skerr = READ_ONCE(sk->sk_err);
+
 	/* Check if error is previously set on socket */
-	if (err || sk->sk_err) {
+	if (err || skerr) {
 		rec = NULL;
 
 		/* If err is already set on socket, return the same code */
-		if (sk->sk_err) {
-			ctx->async_wait.err = -sk->sk_err;
+		if (skerr) {
+			ctx->async_wait.err = -skerr;
 		} else {
 			ctx->async_wait.err = err;
 			tls_err_abort(sk, err);
@@ -701,13 +704,17 @@ static int tls_push_record(struct sock *sk, int flags,
 static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 			       u8 record_type, ssize_t *copied, int flags)
 {
+	int skerr;
 	int err;
 
 	err = tls_push_record(sk, flags, record_type);
-	if (err && err != -EINPROGRESS && sk->sk_err == EBADMSG) {
-		*copied -= sk_msg_free(sk, msg);
-		tls_free_open_rec(sk);
-		err = -sk->sk_err;
+	if (err && err != -EINPROGRESS) {
+		skerr = READ_ONCE(sk->sk_err);
+		if (skerr == EBADMSG) {
+			*copied -= sk_msg_free(sk, msg);
+			tls_free_open_rec(sk);
+			err = -skerr;
+		}
 	}
 	return err;
 }
@@ -800,10 +807,9 @@ static int tls_sw_sendmsg_locked(struct sock *sk, struct msghdr *msg,
 	}
 
 	while (msg_data_left(msg)) {
-		if (sk->sk_err) {
-			ret = -sk->sk_err;
+		ret = -READ_ONCE(sk->sk_err);
+		if (ret)
 			goto send_end;
-		}
 
 		if (ctx->open_rec)
 			rec = ctx->open_rec;
@@ -1098,6 +1104,7 @@ tls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 	int ret = 0;
+	int skerr;
 	long timeo;
 
 	/* a rekey is pending, let userspace deal with it */
@@ -1107,10 +1114,14 @@ tls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)
 	timeo = sock_rcvtimeo(sk, nonblock);
 
 	while (!tls_strp_msg_ready(ctx)) {
-		if (sk->sk_err) {
-			if (has_copied)
-				return -READ_ONCE(sk->sk_err);
-			return sock_error(sk);
+		if (has_copied) {
+			skerr = READ_ONCE(sk->sk_err);
+			if (skerr)
+				return -skerr;
+		} else {
+			skerr = sock_error(sk);
+			if (skerr)
+				return skerr;
 		}
 
 		if (ret < 0)
@@ -1132,10 +1143,14 @@ tls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)
 		 * sk_err here so a connection abort surfaces as the
 		 * actual error rather than a clean EOF.
 		 */
-		if (sk->sk_err) {
-			if (has_copied)
-				return -READ_ONCE(sk->sk_err);
-			return sock_error(sk);
+		if (has_copied) {
+			skerr = READ_ONCE(sk->sk_err);
+			if (skerr)
+				return -skerr;
+		} else {
+			skerr = sock_error(sk);
+			if (skerr)
+				return skerr;
 		}
 		if (sk->sk_shutdown & RCV_SHUTDOWN)
 			return 0;

gemini-3.8-flash

null

null

							input: 5156
							output: 34
							thoughts: 712
						

**Fuzzing Potential: A Quick Assessment**

Okay, so I've got this patch series in front of me, and the question is: does this warrant a syzkaller fuzzing session? Let's break it down. First, I need to check the diff against the HEAD commit in the workspace. Alright, let's see what's changed.

The patch touches a few files: `include/linux/skmsg.h`, `net/core/skbuff.c`, `net/strparser/strparser.c`, `net/tls/tls_device.c`, and `net/tls/tls_sw.c`. The common thread seems to be around `sk->sk_err`, which indicates error handling within the sockets layer. I see `WRITE_ONCE` and `READ_ONCE` being used, which hints at potential concurrency issues, something fuzzers love to exploit.

Specifically, I'm seeing changes related to how `sk->sk_err` is set and read in several functions. I see `sk_psock_report_error()`, `sock_dequeue_err_skb()`, `strp_abort_strp()`, and `tls_push_data()`. These all seem straightforward.

However, the changes in `net/tls/tls_sw.c` are a bit more interesting. I'm seeing multiple instances where `READ_ONCE(sk->sk_err)` is used and I noticed a significant change in `tls_rx_rec_wait()`. The *old* code checked `if (sk->sk_err)` to check if it was non-zero. The *new* code, when `has_copied` is false, unconditionally calls `sock_error(sk)`. That's a semantic change I need to investigate further. `sock_error(sk)` consumes the error, it zeroes `sk->sk_err` via `xchg(&sk->sk_err, 0)`.

A semantic change like that is a prime candidate for fuzzing. I need to understand what this `sock_error(sk)` is doing in detail and how the change affects the error handling logic, so I'm going to quickly check its definition using `grepper` (or by looking at `include/net/sock.h`). Then, I'll be in a better position to determine if syzkaller is the right tool to give this patch a good workout.

{
  "Expression": "static inline int sock_error",
  "PathPrefixes": [
    "include/net/sock.h"
  ]
}

{
  "Output": "include/net/sock.h=2553=struct sk_buff *sock_dequeue_err_skb(struct sock *sk);\n--\ninclude/net/sock.h-2558-\ninclude/net/sock.h:2559:static inline int sock_error(struct sock *sk)\ninclude/net/sock.h-2560-{\n"
}

gemini-3.8-flash

null

null

							input: 6527
							output: 36
							thoughts: 19
						

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

**Diving into the `sock_error` Macro**

Right, let's pull up `sock_error` from `include/net/sock.h`. I'm guessing this is where the kernel handles the reporting of socket errors, likely mapping internal error codes to user-space visible values, and maybe even setting the `errno` appropriately. I need to refresh my memory on the interactions here, especially around how it deals with races or concurrency issues in a multithreaded environment. I'll be looking for how it handles things like `EAGAIN`, `EWOULDBLOCK`, and the various connection-related errors (ECONNRESET, etc.). It's also worth seeing if there are any subtle interactions with signaling mechanisms or workqueues within the network stack. I'm keen to spot any potential locking issues or inefficiencies in the error propagation path, especially considering the performance-critical nature of socket operations. I'll be also looking for how it interacts with the different socket families (IPv4, IPv6, UNIX sockets) and their respective error handling mechanisms. A solid understanding of this is crucial to diagnose those seemingly cryptic socket errors that pop up in real-world applications. Time to dig in!

{
  "File": "include/net/sock.h",
  "FirstLine": 2555,
  "LineCount": 20
}

{
  "Contents": "2555:\t/*\n2556:\t *\tRecover an error report and clear atomically\n2557:\t */\n2558:\t\n2559:\tstatic inline int sock_error(struct sock *sk)\n2560:\t{\n2561:\t\tint err;\n2562:\t\n2563:\t\t/* Avoid an atomic operation for the common case.\n2564:\t\t * This is racy since another cpu/thread can change sk_err under us.\n2565:\t\t */\n2566:\t\tif (likely(data_race(!sk-\u003esk_err)))\n2567:\t\t\treturn 0;\n2568:\t\n2569:\t\terr = xchg(\u0026sk-\u003esk_err, 0);\n2570:\t\treturn -err;\n2571:\t}\n2572:\t\n2573:\tvoid sk_error_report(struct sock *sk);\n2574:\t\n"
}

gemini-3.8-flash

null

null

							input: 7112
							output: 36
							thoughts: 725
						

**Analyzing a Network Code Patch: A Fuzzing Perspective**

Okay, so I'm looking at this code snippet, and my immediate concern is how error handling interacts with the loop in `tls_rx_rec_wait()`. The key is that `sock_error(sk)` *could* potentially clear `sk->sk_err` which is critical to understand if we are looking at something like a race condition, or some other unexpected behavior. We're in a loop and depending on the value of `has_copied`, there's a different path, where if `has_copied` is false, `sock_error()` is called which is a potential issue.

The thing that throws a red flag is this check: `sock_error()` returning a *negative* error code. It's a subtle point, but if `sk->sk_err` is set, the function returns `-err`. The surrounding logic suggests the code *intends* to handle socket errors, so I need to understand this interplay precisely.

The code seems to be addressing a potential race condition where the socket error might get cleared between checks. If I were reviewing this, I'd want to understand the exact circumstances under which `sk->sk_err` might be cleared by `sock_error()` and how this new logic affects the race window.

Alright, so the commit message itself doesn't offer much insight directly, but based on the code changes and the subsystems touched (`net/core/skbuff.c`, `net/tls/tls_sw.c`, `net/tls/tls_device.c`, `net/strparser/strparser.c`, `include/linux/skmsg.h`), which are core networking and kTLS, this definitely falls under "WorthFuzzing" criteria.

Let's apply the WorthFuzzing rules: Reachability is key. kTLS is definitely reachable because Syzkaller and QEMU test it heavily through the standard network stack (`AF_INET`/`AF_INET6` + `TCP_ULP` -> `tls`) and `setsockopt` calls.

The core subsystems modified – networking and kTLS – mean this is a high-priority fuzzing target. The patch clearly touches core networking and kTLS subsystems. The rule "DO NOT BLINDLY TRUST 'NO FUNCTIONAL CHANGE'" applies here; regardless of claims about refactoring, any logic changes in core subsystems warrant fuzzing.

My next step is to carefully check the configurations. I need to figure out which Kconfig options enable TLS and the modified files by searching Kconfig for `net/tls`, `net/strparser`, and `net/core/skbuff.c`. This will give me the environment I need to run this code and verify this code change.

{
  "Expression": "obj-.*tls",
  "PathPrefixes": [
    "net/tls/Makefile",
    "net/Makefile"
  ]
}

{
  "Output": "net/Makefile=17=obj-$(CONFIG_INET)\t\t+= ipv4/\nnet/Makefile:18:obj-$(CONFIG_TLS)\t\t+= tls/\nnet/Makefile-19-obj-$(CONFIG_XFRM)\t\t+= xfrm/\n--\nnet/tls/Makefile=6=CFLAGS_trace.o := -I$(src)\nnet/tls/Makefile-7-\nnet/tls/Makefile:8:obj-$(CONFIG_TLS) += tls.o\nnet/tls/Makefile-9-\n"
}

gemini-3.8-flash

null

null

							input: 8592
							output: 31
							thoughts: 32
						

Okay, let's dive into this. Here's how I'd approach that snippet, considering my expertise:

**Checking the TLS Compilation Process**

Alright, so someone's asked me to look into how `tls_device.c` and `tls_sw.c` get compiled, specifically within the `net/tls` directory. My initial thought is to go straight to the `Makefile` in that directory. That's the logical place to start – it's the build system's blueprint, the script that defines the build rules and dependencies for this particular module. I'd expect to find the relevant compilation commands, linker directives, and any conditional logic that controls how these two specific source files are handled. I'm looking for the standard compile flags (like `-I` for include paths, `-D` for defines, `-O` for optimization) and how they relate to the target architecture or chosen TLS implementation. It's also possible there's some conditional compilation going on here based on whether we're targeting a hardware TLS device or a software-based implementation. Finding this out should provide valuable context.

{
  "File": "net/tls/Makefile",
  "FirstLine": 1,
  "LineCount": 30
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0-only\n   2:\t#\n   3:\t# Makefile for the TLS subsystem.\n   4:\t#\n   5:\t\n   6:\tCFLAGS_trace.o := -I$(src)\n   7:\t\n   8:\tobj-$(CONFIG_TLS) += tls.o\n   9:\t\n  10:\ttls-y := tls_main.o tls_sw.o tls_proc.o trace.o tls_strp.o\n  11:\t\n  12:\ttls-$(CONFIG_TLS_DEVICE) += tls_device.o tls_device_fallback.o\n"
}

gemini-3.8-flash

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null

							input: 9061
							output: 29
							thoughts: 70
						

Here's my summary, as I see it:

**Investigating TLS Compilation Dependencies**

Okay, so I'm looking at how the TLS support is built into this system. I see that the object file `tls_sw.o` is only compiled if the `CONFIG_TLS` flag is set during the build process, which makes sense. Similarly, `tls_device.o` is tied to `CONFIG_TLS_DEVICE`. Now, the crucial part is understanding the *dependencies* these configurations have. To get the whole picture of what enabling TLS actually entails, I need to dig into the `net/tls/Kconfig` file. That's where all the configuration dependencies are defined, and where I'll find out what other options are pulled in when either of these main TLS configurations are enabled. Let's go check that Kconfig file.

{
  "Expression": "config TLS",
  "PathPrefixes": [
    "net/tls/Kconfig"
  ]
}

{
  "Output": "net/tls/Kconfig-4-#\nnet/tls/Kconfig:5:config TLS\nnet/tls/Kconfig-6-\ttristate \"Transport Layer Security support\"\n--\nnet/tls/Kconfig-18-\nnet/tls/Kconfig:19:config TLS_DEVICE\nnet/tls/Kconfig-20-\tbool \"Transport Layer Security HW offload\"\n"
}

gemini-3.8-flash

null

null

							input: 9443
							output: 32
							thoughts: 12
						

Okay, here's my interpretation of that thought process, tailored for an expert audience, and written in the first person:

**Diving into the `net/tls/Kconfig` File**

Alright, let's get down to brass tacks. The mental cue here is clear: it's time to dig into the `net/tls/Kconfig` file. Given the context, I'm assuming we're dealing with the configuration options for TLS within a network-focused kernel environment, likely within a Linux-based system. My first thought is to assess the scope. Is this a new project, or am I troubleshooting something specific? That will inform how deeply I need to go.

My mind's already racing through what I expect to see. I anticipate a structured file format, likely using the Kconfig language. I'll be looking for configuration options related to different TLS versions (1.2, 1.3, potentially even experimental older versions), supported cipher suites, key exchange algorithms (ECDHE, RSA, etc.), and potential hardware acceleration features. I'm hoping it's well-commented; good Kconfig files are a joy to work with.

Beyond the specific options, I'll be scanning for dependencies and relationships. How are these TLS options linked to other kernel subsystems or network components? Are there any obvious security considerations or potential performance trade-offs that are immediately apparent? I’ll be checking whether there are any defaults.

Essentially, I'm expecting to construct a mental model of the available TLS configuration choices. I will understand the design and rationale behind them. From that, I will be ready to address the question at hand, be it understanding the available options, a potential tweak or enhancement, or troubleshooting.

{
  "File": "net/tls/Kconfig",
  "FirstLine": 1,
  "LineCount": 40
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0-only\n   2:\t#\n   3:\t# TLS configuration\n   4:\t#\n   5:\tconfig TLS\n   6:\t\ttristate \"Transport Layer Security support\"\n   7:\t\tdepends on INET\n   8:\t\tselect CRYPTO\n   9:\t\tselect CRYPTO_AES\n  10:\t\tselect CRYPTO_GCM\n  11:\t\tselect NET_SOCK_MSG\n  12:\t\tdefault n\n  13:\t\thelp\n  14:\t\tEnable kernel support for TLS protocol. This allows symmetric\n  15:\t\tencryption handling of the TLS protocol to be done in-kernel.\n  16:\t\n  17:\t\tIf unsure, say N.\n  18:\t\n  19:\tconfig TLS_DEVICE\n  20:\t\tbool \"Transport Layer Security HW offload\"\n  21:\t\tdepends on TLS\n  22:\t\tselect SKB_DECRYPTED\n  23:\t\tselect SOCK_VALIDATE_XMIT\n  24:\t\tselect SOCK_RX_QUEUE_MAPPING\n  25:\t\tdefault n\n  26:\t\thelp\n  27:\t\tEnable kernel support for HW offload of the TLS protocol.\n  28:\t\n  29:\t\tIf unsure, say N.\n"
}

gemini-3.8-flash

null

null

							input: 10176
							output: 25
							thoughts: 23
						

Okay, here's my summarized thought process, assuming I'm an expert and this is a common task:

**Debugging the `strparser` Enablement**

Alright, so I need to figure out what's enabling, or disabling, this `strparser` functionality. My first instinct, given my experience with build systems, is to dive straight into the configuration files. I'm going to quickly check `net/strparser/Kconfig` – that's the obvious place where a new feature like this would be controlled by a configuration option. If it *is* controlled by `Kconfig`, I can trace the dependencies from there. If I don't find it there, my next port of call is the `Makefile` within the `net/strparser` directory. Sometimes the enablement is handled directly in the build process through some conditional compilation. That will show me if there are any specific compilation flags I need to consider, or potential dependencies on other modules. This is a pretty standard debugging approach for build-time issues, so I'll be able to track it down pretty quickly.

{
  "Expression": "strparser",
  "PathPrefixes": [
    "net/"
  ]
}

{
  "Output": "\nFull output is too long, showing 200 out of 363 lines.\nUse more precise expression or PathPrefixes if possible.\n\nNumber of matching lines per file (13 files in total):\nnet/Kconfig:1\nnet/Makefile:1\nnet/core/skmsg.c:6\nnet/ipv4/tcp_bpf.c:2\nnet/kcm/kcmsock.c:5\nnet/strparser/Makefile:1\nnet/strparser/strparser.c:17\nnet/tls/tls.h:14\nnet/tls/tls_device.c:2\nnet/tls/tls_main.c:2\nnet/tls/tls_strp.c:28\nnet/tls/tls_sw.c:7\nnet/xfrm/espintcp.c:3\n\nnet/Kconfig=418=source \"net/kcm/Kconfig\"\nnet/Kconfig:419:source \"net/strparser/Kconfig\"\nnet/Kconfig-420-source \"net/mctp/Kconfig\"\n--\nnet/Makefile=34=obj-$(CONFIG_AF_KCM)\t\t+= kcm/\nnet/Makefile:35:obj-$(CONFIG_STREAM_PARSER)\t+= strparser/\nnet/Makefile-36-obj-$(CONFIG_ATM)\t\t+= atm/\n--\nnet/core/skmsg.c=671=static void sk_psock_backlog(struct work_struct *work)\n--\nnet/core/skmsg.c-698-\t\toff = 0;\nnet/core/skmsg.c:699:\t\tif (skb_bpf_strparser(skb)) {\nnet/core/skmsg.c-700-\t\t\tstruct strp_msg *stm = strp_msg(skb);\n--\nnet/core/skmsg.c=996=static int sk_psock_verdict_apply(struct sk_psock *psock, struct sk_buff *skb,\n--\nnet/core/skmsg.c-1025-\t\t\toff = 0;\nnet/core/skmsg.c:1026:\t\t\tif (skb_bpf_strparser(skb)) {\nnet/core/skmsg.c-1027-\t\t\t\tstruct strp_msg *stm = strp_msg(skb);\n--\nnet/core/skmsg.c=1061=static void sk_psock_write_space(struct sock *sk)\n--\nnet/core/skmsg.c-1078-#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)\nnet/core/skmsg.c:1079:static void sk_psock_strp_read(struct strparser *strp, struct sk_buff *skb)\nnet/core/skmsg.c-1080-{\n--\nnet/core/skmsg.c-1098-\t\tret = bpf_prog_run_pin_on_cpu(prog, skb);\nnet/core/skmsg.c:1099:\t\tskb_bpf_set_strparser(skb);\nnet/core/skmsg.c-1100-\t\tret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb));\n--\nnet/core/skmsg.c-1107-\nnet/core/skmsg.c:1108:static int sk_psock_strp_read_done(struct strparser *strp, int err)\nnet/core/skmsg.c-1109-{\n--\nnet/core/skmsg.c-1112-\nnet/core/skmsg.c:1113:static int sk_psock_strp_parse(struct strparser *strp, struct sk_buff *skb)\nnet/core/skmsg.c-1114-{\n--\nnet/ipv4/tcp_bpf.c=15=void tcp_eat_skb(struct sock *sk, struct sk_buff *skb)\n--\nnet/ipv4/tcp_bpf.c-22-\nnet/ipv4/tcp_bpf.c:23:\tif (skb_bpf_strparser(skb))\nnet/ipv4/tcp_bpf.c-24-\t\treturn;\n--\nnet/ipv4/tcp_bpf.c=677=static int tcp_bpf_assert_proto_ops(struct proto *ops)\n--\nnet/ipv4/tcp_bpf.c-687-#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)\nnet/ipv4/tcp_bpf.c:688:int tcp_bpf_strp_read_sock(struct strparser *strp, read_descriptor_t *desc,\nnet/ipv4/tcp_bpf.c-689-\t\t\t   sk_read_actor_t recv_actor)\n--\nnet/kcm/kcmsock.c=352=static void psock_data_ready(struct sock *sk)\n--\nnet/kcm/kcmsock.c-367-/* Called with lower sock held */\nnet/kcm/kcmsock.c:368:static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb)\nnet/kcm/kcmsock.c-369-{\n--\nnet/kcm/kcmsock.c-388-\nnet/kcm/kcmsock.c:389:static int kcm_parse_func_strparser(struct strparser *strp, struct sk_buff *skb)\nnet/kcm/kcmsock.c-390-{\n--\nnet/kcm/kcmsock.c-400-\nnet/kcm/kcmsock.c:401:static int kcm_read_sock_done(struct strparser *strp, int err)\nnet/kcm/kcmsock.c-402-{\n--\nnet/kcm/kcmsock.c=1240=static int kcm_attach(struct socket *sock, struct socket *csock,\n--\nnet/kcm/kcmsock.c-1249-\tstatic const struct strp_callbacks cb = {\nnet/kcm/kcmsock.c:1250:\t\t.rcv_msg = kcm_rcv_strparser,\nnet/kcm/kcmsock.c:1251:\t\t.parse_msg = kcm_parse_func_strparser,\nnet/kcm/kcmsock.c-1252-\t\t.read_sock_done = kcm_read_sock_done,\n--\nnet/strparser/Makefile-1-# SPDX-License-Identifier: GPL-2.0-only\nnet/strparser/Makefile:2:obj-$(CONFIG_STREAM_PARSER) += strparser.o\n--\nnet/strparser/strparser.c-23-#include \u003clinux/workqueue.h\u003e\nnet/strparser/strparser.c:24:#include \u003cnet/strparser.h\u003e\nnet/strparser/strparser.c-25-#include \u003cnet/netns/generic.h\u003e\n--\nnet/strparser/strparser.c=30=static inline struct _strp_msg *_strp_msg(struct sk_buff *skb)\n--\nnet/strparser/strparser.c-36-/* Lower lock held */\nnet/strparser/strparser.c:37:static void strp_abort_strp(struct strparser *strp, int err)\nnet/strparser/strparser.c-38-{\n--\nnet/strparser/strparser.c-62-\nnet/strparser/strparser.c:63:static void strp_start_timer(struct strparser *strp, long timeo)\nnet/strparser/strparser.c-64-{\n--\nnet/strparser/strparser.c-69-/* Lower lock held */\nnet/strparser/strparser.c:70:static void strp_parser_err(struct strparser *strp, int err,\nnet/strparser/strparser.c-71-\t\t\t    read_descriptor_t *desc)\n--\nnet/strparser/strparser.c-78-\nnet/strparser/strparser.c:79:static inline int strp_peek_len(struct strparser *strp)\nnet/strparser/strparser.c-80-{\n--\nnet/strparser/strparser.c=87=static int strp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb,\n--\nnet/strparser/strparser.c-89-{\nnet/strparser/strparser.c:90:\tstruct strparser *strp = (struct strparser *)desc-\u003earg.data;\nnet/strparser/strparser.c-91-\tlong timeo = READ_ONCE(strp-\u003esk-\u003esk_rcvtimeo);\n--\nnet/strparser/strparser.c-314-\nnet/strparser/strparser.c:315:static int default_read_sock_done(struct strparser *strp, int err)\nnet/strparser/strparser.c-316-{\n--\nnet/strparser/strparser.c-320-/* Called with lock held on lower socket */\nnet/strparser/strparser.c:321:static int strp_read_sock(struct strparser *strp)\nnet/strparser/strparser.c-322-{\n--\nnet/strparser/strparser.c-347-/* Lower sock lock held */\nnet/strparser/strparser.c:348:void strp_data_ready(struct strparser *strp)\nnet/strparser/strparser.c-349-{\n--\nnet/strparser/strparser.c=373=EXPORT_SYMBOL_GPL(strp_data_ready);\nnet/strparser/strparser.c-374-\nnet/strparser/strparser.c:375:static void do_strp_work(struct strparser *strp)\nnet/strparser/strparser.c-376-{\n--\nnet/strparser/strparser.c=395=static void strp_work(struct work_struct *w)\nnet/strparser/strparser.c-396-{\nnet/strparser/strparser.c:397:\tdo_strp_work(container_of(w, struct strparser, work));\nnet/strparser/strparser.c-398-}\n--\nnet/strparser/strparser.c=400=static void strp_msg_timeout(struct work_struct *w)\nnet/strparser/strparser.c-401-{\nnet/strparser/strparser.c:402:\tstruct strparser *strp = container_of(w, struct strparser,\nnet/strparser/strparser.c-403-\t\t\t\t\t      msg_timer_work.work);\n--\nnet/strparser/strparser.c-411-\nnet/strparser/strparser.c:412:int strp_init(struct strparser *strp, struct sock *sk,\nnet/strparser/strparser.c-413-\t      const struct strp_callbacks *cb)\n--\nnet/strparser/strparser.c=433=EXPORT_SYMBOL_GPL(strp_init);\nnet/strparser/strparser.c-434-\nnet/strparser/strparser.c:435:void strp_unpause(struct strparser *strp)\nnet/strparser/strparser.c-436-{\n--\nnet/strparser/strparser.c=444=EXPORT_SYMBOL_GPL(strp_unpause);\n--\nnet/strparser/strparser.c-448- */\nnet/strparser/strparser.c:449:void strp_done(struct strparser *strp)\nnet/strparser/strparser.c-450-{\n--\nnet/strparser/strparser.c=465=EXPORT_SYMBOL_GPL(strp_done);\nnet/strparser/strparser.c-466-\nnet/strparser/strparser.c:467:void strp_stop(struct strparser *strp)\nnet/strparser/strparser.c-468-{\n--\nnet/strparser/strparser.c=471=EXPORT_SYMBOL_GPL(strp_stop);\nnet/strparser/strparser.c-472-\nnet/strparser/strparser.c:473:void strp_check_rcv(struct strparser *strp)\nnet/strparser/strparser.c-474-{\n--\nnet/tls/tls.h=144=void tls_err_abort(struct sock *sk, int err);\nnet/tls/tls.h:145:void tls_strp_abort_strp(struct tls_strparser *strp, int err);\nnet/tls/tls.h-146-\n--\nnet/tls/tls.h=152=void tls_update_rx_zc_capable(struct tls_context *tls_ctx);\nnet/tls/tls.h:153:void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);\nnet/tls/tls.h:154:void tls_sw_strparser_done(struct tls_context *tls_ctx);\nnet/tls/tls.h-155-int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);\n--\nnet/tls/tls.h=188=void tls_strp_dev_exit(void);\nnet/tls/tls.h-189-\nnet/tls/tls.h:190:void tls_strp_done(struct tls_strparser *strp);\nnet/tls/tls.h:191:void __tls_strp_done(struct tls_strparser *strp);\nnet/tls/tls.h:192:void tls_strp_stop(struct tls_strparser *strp);\nnet/tls/tls.h:193:int tls_strp_init(struct tls_strparser *strp, struct sock *sk);\nnet/tls/tls.h:194:void tls_strp_data_ready(struct tls_strparser *strp);\nnet/tls/tls.h-195-\nnet/tls/tls.h:196:void tls_strp_check_rcv(struct tls_strparser *strp, bool announce);\nnet/tls/tls.h:197:void tls_strp_msg_consume(struct tls_strparser *strp);\nnet/tls/tls.h-198-\nnet/tls/tls.h:199:int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb);\nnet/tls/tls.h:200:void tls_rx_msg_maybe_announce(struct tls_strparser *strp);\nnet/tls/tls.h-201-\nnet/tls/tls.h:202:bool tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh);\nnet/tls/tls.h-203-int tls_strp_msg_cow(struct tls_sw_context_rx *ctx);\nnet/tls/tls.h=204=struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx);\nnet/tls/tls.h:205:int tls_strp_msg_hold(struct tls_strparser *strp, struct sk_buff_head *dst);\nnet/tls/tls.h-206-\n--\nnet/tls/tls_device.c=887=tls_device_reencrypt(struct sock *sk, struct tls_context *tls_ctx)\n--\nnet/tls/tls_device.c-948-\t\t/* Practically all frags must belong to msg if reencrypt\nnet/tls/tls_device.c:949:\t\t * is needed with current strparser and coalescing logic,\nnet/tls/tls_device.c:950:\t\t * but strparser may \"get optimized\", so let's be safe.\nnet/tls/tls_device.c-951-\t\t */\n--\nnet/tls/tls_main.c=361=static void tls_sk_proto_close(struct sock *sk, long timeout)\n--\nnet/tls/tls_main.c-387-\tif (ctx-\u003erx_conf == TLS_SW || ctx-\u003erx_conf == TLS_HW)\nnet/tls/tls_main.c:388:\t\ttls_sw_strparser_done(ctx);\nnet/tls/tls_main.c-389-\tif (ctx-\u003erx_conf == TLS_SW)\n--\nnet/tls/tls_main.c=621=static int do_tls_setsockopt_conf(struct sock *sk, sockptr_t optval,\n--\nnet/tls/tls_main.c-750-\t\tif (!update)\nnet/tls/tls_main.c:751:\t\t\ttls_sw_strparser_arm(sk, ctx);\n\n"
}

gemini-3.8-flash

null

null

							input: 14711
							output: 33
							thoughts: 13
						

Okay, here's my take on those thoughts, tailored for an expert audience and presented in the first person:

**Navigating the Kconfig Landscape**

Right, let's dive into the core of the matter. I need to get a handle on how this parsing is configured. My initial instinct is to go straight to `net/strparser/Kconfig`. That's usually the place where these things are defined and exposed to the build system. I'm assuming, given the context, that this likely holds the configuration options related to whatever string parsing functionality we're discussing. Things like whether certain features are enabled, default behavior, perhaps even compile-time optimizations based on specific hardware targets. I'll need to scrutinize the dependencies, the *select* statements, and any default values configured to understand the default behavior and how a user can tweak it for their specific environment. The details in the Kconfig will point me towards associated source files to examine or, perhaps, other Kconfig files that include or source this one. This seems like a reasonable starting point before further investigation. I'm keen to see if this is as I expect. Let's see what's in there.

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

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0-only\n   2:\tconfig STREAM_PARSER\n   3:\t\tdef_bool n\n"
}

gemini-3.8-flash

null

null

							input: 15055
							output: 19
							thoughts: 12
						

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

**Investigating the `STREAM_PARSER` Selection**

Okay, so the immediate question here is: *who* is choosing to utilize the `STREAM_PARSER`? We need to pinpoint the code path, the configuration, the module, or the component responsible for making that selection. This isn't just a casual curiosity; the `STREAM_PARSER` choice likely carries performance, memory, or even security implications, depending on the architecture. Is it a default, a user-configurable option, or something determined dynamically based on input characteristics? Understanding this is critical for diagnosing performance bottlenecks, identifying potential vulnerabilities, or ensuring optimal resource utilization. My initial thought would be to look for any initialization code, conditional statements, or configuration settings that directly reference or set the `STREAM_PARSER` value, in this project.

{
  "Expression": "select STREAM_PARSER"
}

{
  "Output": "drivers/net/Kconfig=103=config OVPN\n--\ndrivers/net/Kconfig-111-\tselect CRYPTO_CHACHA20POLY1305\ndrivers/net/Kconfig:112:\tselect STREAM_PARSER\ndrivers/net/Kconfig-113-\thelp\n--\nnet/Kconfig=360=config BPF_STREAM_PARSER\n--\nnet/Kconfig-364-\tdepends on CGROUP_BPF\nnet/Kconfig:365:\tselect STREAM_PARSER\nnet/Kconfig-366-\tselect NET_SOCK_MSG\n--\nnet/ipv4/Kconfig=382=config INET_ESPINTCP\n--\nnet/ipv4/Kconfig-384-\tdepends on XFRM \u0026\u0026 INET_ESP\nnet/ipv4/Kconfig:385:\tselect STREAM_PARSER\nnet/ipv4/Kconfig-386-\tselect NET_SOCK_MSG\n--\nnet/ipv6/Kconfig=90=config INET6_ESPINTCP\n--\nnet/ipv6/Kconfig-92-\tdepends on XFRM \u0026\u0026 INET6_ESP\nnet/ipv6/Kconfig:93:\tselect STREAM_PARSER\nnet/ipv6/Kconfig-94-\tselect NET_SOCK_MSG\n--\nnet/kcm/Kconfig=3=config AF_KCM\n--\nnet/kcm/Kconfig-6-\tselect BPF_SYSCALL\nnet/kcm/Kconfig:7:\tselect STREAM_PARSER\nnet/kcm/Kconfig-8-\thelp\n"
}

gemini-3.8-flash

null

null

							input: 15674
							output: 22
							thoughts: 67
						

Okay, let's dive into this.

**Investigating the Usage of `skmsg.h`**

My immediate thought is to check `skmsg.h`. It's a key file in the networking stack, and I need to understand its scope. Specifically, I'm trying to figure out which modules or functions rely on it. My primary focus right now is on that file.

I've identified `sk_psock_report_error()` as being defined within `include/linux/skmsg.h`. This suggests it's a critical component in this context, so I need to track down exactly where this particular function is employed. My next step will be to ascertain the direct calls to this function. This is critical, as it'll give me a direct view of how the `skmsg.h` header file is utilized.

{
  "Expression": "sk_psock_report_error"
}

{
  "Output": "include/linux/skmsg.h=421=static inline void kfree_sk_msg(struct sk_msg *msg)\n--\ninclude/linux/skmsg.h-427-\ninclude/linux/skmsg.h:428:static inline void sk_psock_report_error(struct sk_psock *psock, int err)\ninclude/linux/skmsg.h-429-{\n--\nnet/core/skmsg.c=671=static void sk_psock_backlog(struct work_struct *work)\n--\nnet/core/skmsg.c-731-\t\t\t\t/* Hard errors break pipe and stop xmit. */\nnet/core/skmsg.c:732:\t\t\t\tsk_psock_report_error(psock, ret ? -ret : EPIPE);\nnet/core/skmsg.c-733-\t\t\t\tsk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);\n"
}

gemini-3.8-flash

null

null

							input: 16185
							output: 28
							thoughts: 43
						

Okay, here's my interpretation of that thought process, from an expert's perspective:

**Debugging a Potential Socket Backlog Issue**

Right, so `sk_psock_backlog` has flagged something, and it's calling `sk_psock_report_error`. That's the signal of some sort of problem with the packet socket backlog. I need to figure out what's going on. First, I need to know where `skmsg.c` is enabled, as the packet socket code can be configured in multiple ways. Now, let's go check the `net/core/Makefile` to see how that module is built, what the config options are, and if the specific features I'm interested in are enabled. Understanding the build context is critical here.

{
  "Expression": "skmsg",
  "PathPrefixes": [
    "net/core/Makefile"
  ]
}

{
  "Output": "net/core/Makefile=43=obj-$(CONFIG_FAILOVER) += failover.o\nnet/core/Makefile:44:obj-$(CONFIG_NET_SOCK_MSG) += skmsg.o\nnet/core/Makefile-45-obj-$(CONFIG_BPF_SYSCALL) += sock_map.o\n"
}

gemini-3.8-flash

null

null

							input: 16512
							output: 22
							thoughts: 91
						

Okay, here's my breakdown of this kernel configuration and code flow, reflecting my expertise:

**Diving into SKB Error Handling**

Alright, so `CONFIG_NET_SOCK_MSG` is flagged, which immediately tells me this is related to socket message handling, likely involving TLS or BPF stream parsers. That's my first clue. My next step, as always, is to follow the data. I'm focusing on `sock_dequeue_err_skb()` within `net/core/skbuff.c`. Of course, `skbuff.c` is going to be present in any networked kernel – that's fundamental. Now, the real question is: where is this error-handling function *actually* called? I need to understand its context and how errors are being propagated. I'm thinking about the possible call sites and what errors can happen. I'm going to start with a quick search of the source code for calls to this function.

{
  "Expression": "sock_dequeue_err_skb"
}

{
  "Output": "include/net/sock.h=2552=int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);\ninclude/net/sock.h:2553:struct sk_buff *sock_dequeue_err_skb(struct sock *sk);\ninclude/net/sock.h-2554-\n--\nnet/core/skbuff.c=5521=static bool is_icmp_err_skb(const struct sk_buff *skb)\n--\nnet/core/skbuff.c-5526-\nnet/core/skbuff.c:5527:struct sk_buff *sock_dequeue_err_skb(struct sock *sk)\nnet/core/skbuff.c-5528-{\n--\nnet/core/skbuff.c-5554-}\nnet/core/skbuff.c:5555:EXPORT_SYMBOL(sock_dequeue_err_skb);\nnet/core/skbuff.c-5556-\n--\nnet/core/sock.c=4020=int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,\n--\nnet/core/sock.c-4027-\terr = -EAGAIN;\nnet/core/sock.c:4028:\tskb = sock_dequeue_err_skb(sk);\nnet/core/sock.c-4029-\tif (skb == NULL)\n--\nnet/ipv4/ip_sockglue.c=523=int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)\n--\nnet/ipv4/ip_sockglue.c-535-\terr = -EAGAIN;\nnet/ipv4/ip_sockglue.c:536:\tskb = sock_dequeue_err_skb(sk);\nnet/ipv4/ip_sockglue.c-537-\tif (!skb)\n--\nnet/ipv6/datagram.c=455=int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)\n--\nnet/ipv6/datagram.c-468-\terr = -EAGAIN;\nnet/ipv6/datagram.c:469:\tskb = sock_dequeue_err_skb(sk);\nnet/ipv6/datagram.c-470-\tif (!skb)\n"
}

gemini-3.8-flash

null

null

							input: 17442
							output: 30
							thoughts: 41
						

Okay, here's my take on those thoughts, framed from my perspective:

**Diving into the TLS Data Push Function**

Alright, let's zero in on `tls_push_data` within `net/tls/tls_device.c`. My immediate goal is to understand its role and impact. I need to trace its usage, see where it's invoked, and what specific tasks it's responsible for. This is where the real work begins – understanding the data flow within the TLS context. Pinpointing the call sites will be key to grasping its purpose and how it fits into the broader network stack. So, let's get digging into the code and see what we can unearth.

{
  "Expression": "tls_push_data",
  "PathPrefixes": [
    "net/tls/"
  ]
}

{
  "Output": "net/tls/tls_device.c=396=static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)\n--\nnet/tls/tls_device.c-420-\nnet/tls/tls_device.c:421:static int tls_push_data(struct sock *sk,\nnet/tls/tls_device.c-422-\t\t\t struct iov_iter *iter,\n--\nnet/tls/tls_device.c=567=int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\n--\nnet/tls/tls_device.c-584-\nnet/tls/tls_device.c:585:\trc = tls_push_data(sk, \u0026msg-\u003emsg_iter, size, msg-\u003emsg_flags,\nnet/tls/tls_device.c-586-\t\t\t   record_type);\n--\nnet/tls/tls_device.c=594=void tls_device_splice_eof(struct socket *sock)\n--\nnet/tls/tls_device.c-609-\t\tiov_iter_bvec(\u0026iter, ITER_SOURCE, NULL, 0, 0);\nnet/tls/tls_device.c:610:\t\ttls_push_data(sk, \u0026iter, 0, 0, TLS_RECORD_TYPE_DATA);\nnet/tls/tls_device.c-611-\t}\n--\nnet/tls/tls_device.c=677=static int tls_device_push_pending_record(struct sock *sk, int flags)\n--\nnet/tls/tls_device.c-681-\tiov_iter_kvec(\u0026iter, ITER_SOURCE, NULL, 0, 0);\nnet/tls/tls_device.c:682:\treturn tls_push_data(sk, \u0026iter, 0, flags, TLS_RECORD_TYPE_DATA);\nnet/tls/tls_device.c-683-}\n"
}

gemini-3.8-flash

null

null

							input: 18165
							output: 38
							thoughts: 130
						

Here's my analysis of the provided code snippets:

**Diving into the TLS Software Encryption in the Linux Kernel**

Okay, so I'm looking at `net/tls/tls_sw.c`. Immediately, I see some key functions that are critical to understand the software TLS implementation. First off, `tls_encrypt_done` - that screams asynchronous crypto callback to me. That's a good starting point for tracing how encryption results are handled. Next, `bpf_exec_tx_verdict` caught my eye; that's the BPF verdict on the TLS socket. I'll need to remember that for analyzing any performance impacts or policy enforcement. Then, `tls_sw_sendmsg_locked` is interesting because it's called from both `tls_sw_sendmsg` and `tls_sw_sendpage_locked`, indicating a central point for handling sending data over the TLS socket, regardless of the underlying API used. Finally, there's `tls_rx_rec_wait`. I know from experience that waiting is usually associated with incoming data. Since this is in the receive path (`tls_sw_recvmsg`), I'm guessing that this is about waiting for TLS messages to arrive. I'll focus on `tls_rx_rec_wait` for this specific analysis. I need to understand how the receiving side works.

{
  "File": "net/tls/tls_sw.c",
  "FirstLine": 1095,
  "LineCount": 70
}

{
  "Contents": "1095:\t/* When has_copied is true the caller has already moved bytes to\n1096:\t * userspace. Report sk_err but leave it set so the next read\n1097:\t * surfaces it instead of a spurious EOF, otherwise sk_err is\n1098:\t * consumed via sock_error().\n1099:\t */\n1100:\tstatic int\n1101:\ttls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)\n1102:\t{\n1103:\t\tstruct tls_context *tls_ctx = tls_get_ctx(sk);\n1104:\t\tstruct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);\n1105:\t\tDEFINE_WAIT_FUNC(wait, woken_wake_function);\n1106:\t\tint ret = 0;\n1107:\t\tint skerr;\n1108:\t\tlong timeo;\n1109:\t\n1110:\t\t/* a rekey is pending, let userspace deal with it */\n1111:\t\tif (unlikely(ctx-\u003ekey_update_pending))\n1112:\t\t\treturn -EKEYEXPIRED;\n1113:\t\n1114:\t\ttimeo = sock_rcvtimeo(sk, nonblock);\n1115:\t\n1116:\t\twhile (!tls_strp_msg_ready(ctx)) {\n1117:\t\t\tif (has_copied) {\n1118:\t\t\t\tskerr = READ_ONCE(sk-\u003esk_err);\n1119:\t\t\t\tif (skerr)\n1120:\t\t\t\t\treturn -skerr;\n1121:\t\t\t} else {\n1122:\t\t\t\tskerr = sock_error(sk);\n1123:\t\t\t\tif (skerr)\n1124:\t\t\t\t\treturn skerr;\n1125:\t\t\t}\n1126:\t\n1127:\t\t\tif (ret \u003c 0)\n1128:\t\t\t\treturn ret;\n1129:\t\n1130:\t\t\tif (sk_flush_backlog(sk))\n1131:\t\t\t\treleased = true;\n1132:\t\t\tif (!skb_queue_empty(\u0026sk-\u003esk_receive_queue)) {\n1133:\t\t\t\t/* Defer notification to the exit point; this thread\n1134:\t\t\t\t * will consume the record directly.\n1135:\t\t\t\t */\n1136:\t\t\t\ttls_strp_check_rcv(\u0026ctx-\u003estrp, false);\n1137:\t\t\t\tif (tls_strp_msg_ready(ctx))\n1138:\t\t\t\t\tbreak;\n1139:\t\t\t}\n1140:\t\n1141:\t\t\t/* sk_flush_backlog() can run tcp_reset(), which sets\n1142:\t\t\t * sk_err and then sk_shutdown via tcp_done(). Recheck\n1143:\t\t\t * sk_err here so a connection abort surfaces as the\n1144:\t\t\t * actual error rather than a clean EOF.\n1145:\t\t\t */\n1146:\t\t\tif (has_copied) {\n1147:\t\t\t\tskerr = READ_ONCE(sk-\u003esk_err);\n1148:\t\t\t\tif (skerr)\n1149:\t\t\t\t\treturn -skerr;\n1150:\t\t\t} else {\n1151:\t\t\t\tskerr = sock_error(sk);\n1152:\t\t\t\tif (skerr)\n1153:\t\t\t\t\treturn skerr;\n1154:\t\t\t}\n1155:\t\t\tif (sk-\u003esk_shutdown \u0026 RCV_SHUTDOWN)\n1156:\t\t\t\treturn 0;\n1157:\t\n1158:\t\t\tif (sock_flag(sk, SOCK_DONE))\n1159:\t\t\t\treturn 0;\n1160:\t\n1161:\t\t\tif (!timeo)\n1162:\t\t\t\treturn -EAGAIN;\n1163:\t\n1164:\t\t\treleased = true;\n"
}

gemini-3.8-flash

null

null

							input: 19640
							output: 32
							thoughts: 274
						

**Analyzing a Patch for Data Race Prevention in the Kernel**

Okay, let's take a look at this patch. My immediate thought is, "Ah, finally, someone's cleaning up these data race issues and potentially missing annotations." I'm seeing a pattern here – the use of `READ_ONCE`, `WRITE_ONCE`, and correct calls to `sock_error(sk)`. This is precisely the kind of low-level synchronization that's crucial for kernel stability, especially when dealing with shared socket structures.

The modifications are scattered across a few key areas, which tells me this patch has a broad impact on several parts of the networking stack. Specifically, I'm noting these changes:

1.  `sk_psock_report_error` in `include/linux/skmsg.h`: I'm observing the use of `WRITE_ONCE` to update `sk->sk_err`. Makes sense; this is about atomically writing the error code.
2.  `sock_dequeue_err_skb` in `net/core/skbuff.c`: The same `WRITE_ONCE` pattern is evident here as well, likely a critical area for ensuring error handling is consistent.
3.  `strp_abort_strp` in `net/strparser/strparser.c`: I see a similar pattern with `WRITE_ONCE(sk->sk_err, -err)`, I'll have to investigate the specific meaning of the negative error code here.
4.  `tls_push_data` in `net/tls/tls_device.c`: And here we have `rc = -READ_ONCE(sk->sk_err)`, the `READ_ONCE` function, meaning that the error code is read in a safe manner to avoid data races.
5.  Various functions within `net/tls/tls_sw.c`: `tls_encrypt_done`, `bpf_exec_tx_verdict`, `tls_sw_sendmsg_locked`, and `tls_rx_rec_wait`. I'm going to pay close attention to the implications in the TLS software implementation. I notice that `tls_rx_rec_wait` is being updated with `READ_ONCE` as well. Since this function is crucial to TLS, I should probably check where it is used.

{
  "Expression": "tls_rx_rec_wait",
  "PathPrefixes": [
    "net/tls/"
  ]
}

{
  "Output": "net/tls/tls_sw.c=1100=static int\nnet/tls/tls_sw.c:1101:tls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)\nnet/tls/tls_sw.c-1102-{\n--\nnet/tls/tls_sw.c-1177-\tif (unlikely(!tls_strp_msg_load(\u0026ctx-\u003estrp, released)))\nnet/tls/tls_sw.c:1178:\t\treturn tls_rx_rec_wait(sk, nonblock, false, has_copied);\nnet/tls/tls_sw.c-1179-\n--\nnet/tls/tls_sw.c=1821=int tls_sw_recvmsg(struct sock *sk,\n--\nnet/tls/tls_sw.c-1875-\nnet/tls/tls_sw.c:1876:\t\terr = tls_rx_rec_wait(sk, flags \u0026 MSG_DONTWAIT,\nnet/tls/tls_sw.c-1877-\t\t\t\t      released, !!(decrypted + copied));\n--\nnet/tls/tls_sw.c=2014=ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,\n--\nnet/tls/tls_sw.c-2041-\nnet/tls/tls_sw.c:2042:\t\terr = tls_rx_rec_wait(sk, flags \u0026 SPLICE_F_NONBLOCK,\nnet/tls/tls_sw.c-2043-\t\t\t\t      true, false);\n--\nnet/tls/tls_sw.c=2088=int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,\n--\nnet/tls/tls_sw.c-2126-\nnet/tls/tls_sw.c:2127:\t\t\terr = tls_rx_rec_wait(sk, true, released, !!copied);\nnet/tls/tls_sw.c-2128-\t\t\tif (err \u003c= 0)\n"
}

gemini-3.8-flash

null

null

							input: 20980
							output: 33
							thoughts: 19
						

Okay, let's dive in.

**Tracing the `tls_sw_sendmsg_locked` Function**

Right, time to get to work. First things first, I need to figure out where this `tls_sw_sendmsg_locked` function is being called. That's the crucial initial step. It's the only way to understand its context and how it's being used. I need to trace its usage patterns. I'll need to figure out the calling functions, and understand the calling context to analyze the flow.

{
  "Expression": "tls_sw_sendmsg_locked",
  "PathPrefixes": [
    "net/tls/"
  ]
}

{
  "Output": "net/tls/tls_sw.c=742=static int tls_sw_sendmsg_splice(struct sock *sk, struct msghdr *msg,\n--\nnet/tls/tls_sw.c-772-\nnet/tls/tls_sw.c:773:static int tls_sw_sendmsg_locked(struct sock *sk, struct msghdr *msg,\nnet/tls/tls_sw.c-774-\t\t\t\t size_t size)\n--\nnet/tls/tls_sw.c=1014=int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\n--\nnet/tls/tls_sw.c-1027-\tlock_sock(sk);\nnet/tls/tls_sw.c:1028:\tret = tls_sw_sendmsg_locked(sk, msg, size);\nnet/tls/tls_sw.c-1029-\trelease_sock(sk);\n"
}

gemini-3.8-flash

null

null

							input: 21398
							output: 34
							thoughts: 107
						

**Analyzing the Transmission Verdict in TLS Encryption**

Okay, let's break this down. My focus right now is on understanding how we're handling the transmission verdict within our TLS encryption process. Specifically, I need to understand how the `tls_encrypt_done` callback integrates with the overall flow. As a reminder, this is the asynchronous callback that triggers after the TLS crypto encryption is complete, receiving the result (`err`) and any associated data.

I'm particularly interested in how `bpf_exec_tx_verdict` is used here. I know that's called from both `tls_sw_sendmsg_locked` and `tls_sw_sendmsg_splice` (or `tls_sw_sendpage_locked`). So, the next logical step is to pinpoint the exact call sites of `bpf_exec_tx_verdict` to fully map the transmission path.

{
  "Expression": "bpf_exec_tx_verdict",
  "PathPrefixes": [
    "net/tls/"
  ]
}

{
  "Output": "net/tls/tls_sw.c=620=static int tls_push_record(struct sock *sk, int flags,\n--\nnet/tls/tls_sw.c-703-\nnet/tls/tls_sw.c:704:static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,\nnet/tls/tls_sw.c-705-\t\t\t       u8 record_type, ssize_t *copied, int flags)\n--\nnet/tls/tls_sw.c=722=static int tls_sw_push_pending_record(struct sock *sk, int flags)\n--\nnet/tls/tls_sw.c-737-\nnet/tls/tls_sw.c:738:\treturn bpf_exec_tx_verdict(msg_pl, sk, TLS_RECORD_TYPE_DATA,\nnet/tls/tls_sw.c-739-\t\t\t\t   \u0026copied, flags);\n--\nnet/tls/tls_sw.c=773=static int tls_sw_sendmsg_locked(struct sock *sk, struct msghdr *msg,\n--\nnet/tls/tls_sw.c-892-\t\t\tsk_msg_sg_copy_set(msg_pl, first);\nnet/tls/tls_sw.c:893:\t\t\tret = bpf_exec_tx_verdict(msg_pl, sk,\nnet/tls/tls_sw.c-894-\t\t\t\t\t\t  record_type, \u0026copied,\n--\nnet/tls/tls_sw.c-952-\t\tif (full_record || eor) {\nnet/tls/tls_sw.c:953:\t\t\tret = bpf_exec_tx_verdict(msg_pl, sk,\nnet/tls/tls_sw.c-954-\t\t\t\t\t\t  record_type, \u0026copied,\n--\nnet/tls/tls_sw.c=1037=void tls_sw_splice_eof(struct socket *sock)\n--\nnet/tls/tls_sw.c-1064-\t/* Perform transmission. */\nnet/tls/tls_sw.c:1065:\tret = bpf_exec_tx_verdict(msg_pl, sk, TLS_RECORD_TYPE_DATA,\nnet/tls/tls_sw.c-1066-\t\t\t\t  \u0026copied, 0);\n"
}

gemini-3.8-flash

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							input: 22317
							output: 33
							thoughts: 103
						

Okay, let's break this down.

**Investigating Error Reporting in the Sockets Layer**

Right, so I need to track down the error reporting path from the socket layer. I remember seeing `sk_psock_report_error` somewhere, so let's start there. Ah, yes, looking in `net/core/skmsg.c`, specifically the `sk_psock_backlog` function. It looks like this function calls `sk_psock_report_error` with either a negative return value (`-ret`) or `EPIPE`. Good, that gives me a clear entry point. Now I need to know under what conditions are errors being reported, and, most importantly, where the calls come from. 

Now, I also see that `strp_abort_strp` is a function that might be of interest. So, let me quickly pivot to look for the call sites of `strp_abort_strp` and see if there are any interesting interactions.

{
  "Expression": "strp_abort_strp",
  "PathPrefixes": [
    "net/strparser/"
  ]
}

{
  "Output": "net/strparser/strparser.c=30=static inline struct _strp_msg *_strp_msg(struct sk_buff *skb)\n--\nnet/strparser/strparser.c-36-/* Lower lock held */\nnet/strparser/strparser.c:37:static void strp_abort_strp(struct strparser *strp, int err)\nnet/strparser/strparser.c-38-{\n--\nnet/strparser/strparser.c=70=static void strp_parser_err(struct strparser *strp, int err,\n--\nnet/strparser/strparser.c-75-\tstrp-\u003eskb_head = NULL;\nnet/strparser/strparser.c:76:\tstrp_abort_strp(strp, err);\nnet/strparser/strparser.c-77-}\n--\nnet/strparser/strparser.c=400=static void strp_msg_timeout(struct work_struct *w)\n--\nnet/strparser/strparser.c-407-\tlock_sock(strp-\u003esk);\nnet/strparser/strparser.c:408:\tstrp_abort_strp(strp, -ETIMEDOUT);\nnet/strparser/strparser.c-409-\trelease_sock(strp-\u003esk);\n"
}

gemini-3.8-flash

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							input: 23005
							output: 44
							thoughts: 1140
						

**Fuzzing Target Identification: A Deep Dive into Kernel TLS Error Handling**

Okay, so I've got a handle on this patch. My initial assessment is that this is *definitely* worth fuzzing. The fact that these code paths are reachable in standard QEMU/KVM environments using kTLS via `setsockopt` on TCP sockets, and the involvement of `strparser` (used in KCM, BPF, ESP, TLS, and ovpn) as well as `sock_dequeue_err_skb` with its `MSG_ERRQUEUE` handling, suggests a wide attack surface.

The core of the change revolves around how the `sk->sk_err` field is read, written, and ultimately consumed. This touches critical functions, including `tls_rx_rec_wait()`, `tls_sw_sendmsg_locked()`, `sock_dequeue_err_skb()`, and `strp_abort_strp()`. I need to understand this refactoring in `tls_rx_rec_wait()`. It seems that the original code, when `sk->sk_err` was non-zero, would either return the error or call `sock_error(sk)`. Now, if `!has_copied` the code calls `sock_error(sk)` which, if `sk->sk_err != 0`, performs an atomic exchange with zero using `xchg()`. This is important, as it introduces new concurrency considerations. Furthermore, they are modifying concurrency handling for `sk_err` in `tls_device.c`, `tls_sw.c`, and `net/core/skbuff.c`. This is my focus.

Now, let's nail down the focus symbols, making sure I adhere to the guidelines. I need to avoid ubiquitous lifecycle hot-paths and target specific feature logic and entry points. I can't look at inline static functions.

Here is the breakdown, based on the modified functions:

1.  `include/linux/skmsg.h`: `sk_psock_report_error()` is a static inline and its caller is `sk_psock_backlog`. I will skip it.
2.  `net/core/skbuff.c`: `sock_dequeue_err_skb` is an exported symbol, and it's directly called by `sock_recv_errqueue`, `ip_recv_error`, and `ipv6_recv_error`. That is a clear target!
3.  `net/strparser/strparser.c`: `strp_abort_strp` is static, but its callers, `strp_parser_err` (called by `strp_recv`) and `strp_msg_timeout`, as well as `strp_recv`, `strp_data_ready`, and `do_strp_work` provide excellent coverage points.
4.  `net/tls/tls_device.c`: `tls_push_data` is static, but `tls_device_sendmsg` and `tls_device_splice_eof` are non-static and worthwhile.
5.  `net/tls/tls_sw.c`: Here's where it gets interesting. `tls_encrypt_done`, `bpf_exec_tx_verdict` and `tls_sw_sendmsg_locked` are static, but the fact that `tls_sw_sendmsg` and potentially `tls_sw_recvmsg` are *non-static* is crucial! And non-static callers for `tls_rx_rec_wait` are `tls_sw_recvmsg`, `tls_sw_splice_read`, and `tls_sw_read_sock`.

Now, I need to confirm: can I focus on `tls_sw_sendmsg`, `tls_sw_recvmsg`, `tls_sw_splice_read`, and `tls_sw_read_sock`? I will check `net/tls/tls_sw.c` to confirm.

{
  "Expression": "^(int|void|ssize_t) tls_sw_",
  "PathPrefixes": [
    "net/tls/tls_sw.c"
  ]
}

{
  "Output": "net/tls/tls_sw.c=773=static int tls_sw_sendmsg_locked(struct sock *sk, struct msghdr *msg,\n--\nnet/tls/tls_sw.c-1013-\nnet/tls/tls_sw.c:1014:int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\nnet/tls/tls_sw.c-1015-{\n--\nnet/tls/tls_sw.c-1036- */\nnet/tls/tls_sw.c:1037:void tls_sw_splice_eof(struct socket *sock)\nnet/tls/tls_sw.c-1038-{\n--\nnet/tls/tls_sw.c=1815=static void tls_rx_reader_unlock(struct sock *sk, struct tls_sw_context_rx *ctx)\n--\nnet/tls/tls_sw.c-1820-\nnet/tls/tls_sw.c:1821:int tls_sw_recvmsg(struct sock *sk,\nnet/tls/tls_sw.c-1822-\t\t   struct msghdr *msg,\n--\nnet/tls/tls_sw.c-2013-\nnet/tls/tls_sw.c:2014:ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,\nnet/tls/tls_sw.c-2015-\t\t\t   struct pipe_inode_info *pipe,\n--\nnet/tls/tls_sw.c-2087-\nnet/tls/tls_sw.c:2088:int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,\nnet/tls/tls_sw.c-2089-\t\t     sk_read_actor_t read_actor)\n--\nnet/tls/tls_sw.c=2274=static void tls_data_ready(struct sock *sk)\n--\nnet/tls/tls_sw.c-2287-\nnet/tls/tls_sw.c:2288:void tls_sw_cancel_work_tx(struct tls_context *tls_ctx)\nnet/tls/tls_sw.c-2289-{\n--\nnet/tls/tls_sw.c-2296-\nnet/tls/tls_sw.c:2297:void tls_sw_release_resources_tx(struct sock *sk)\nnet/tls/tls_sw.c-2298-{\n--\nnet/tls/tls_sw.c-2330-\nnet/tls/tls_sw.c:2331:void tls_sw_free_ctx_tx(struct tls_context *tls_ctx)\nnet/tls/tls_sw.c-2332-{\n--\nnet/tls/tls_sw.c-2337-\nnet/tls/tls_sw.c:2338:void tls_sw_release_resources_rx(struct sock *sk)\nnet/tls/tls_sw.c-2339-{\n--\nnet/tls/tls_sw.c-2358-\nnet/tls/tls_sw.c:2359:void tls_sw_strparser_done(struct tls_context *tls_ctx)\nnet/tls/tls_sw.c-2360-{\n--\nnet/tls/tls_sw.c-2365-\nnet/tls/tls_sw.c:2366:void tls_sw_free_ctx_rx(struct tls_context *tls_ctx)\nnet/tls/tls_sw.c-2367-{\n--\nnet/tls/tls_sw.c-2372-\nnet/tls/tls_sw.c:2373:void tls_sw_free_resources_rx(struct sock *sk)\nnet/tls/tls_sw.c-2374-{\n--\nnet/tls/tls_sw.c=2419=static bool tls_is_tx_ready(struct tls_sw_context_tx *ctx)\n--\nnet/tls/tls_sw.c-2429-\nnet/tls/tls_sw.c:2430:void tls_sw_write_space(struct sock *sk, struct tls_context *ctx)\nnet/tls/tls_sw.c-2431-{\n--\nnet/tls/tls_sw.c-2439-\nnet/tls/tls_sw.c:2440:void tls_sw_strparser_arm(struct sock *sk, struct tls_context *tls_ctx)\nnet/tls/tls_sw.c-2441-{\n"
}

gemini-3.8-flash

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							input: 26222
							output: 33
							thoughts: 1366
						

**Focusing on Target Functions and Configurations**

Okay, so I'm looking at how to best guide the fuzzer, and the prompt is emphasizing two critical things: targeting *specific* feature logic and entrypoints while avoiding ubiquitous functions.  The goal is to focus the fuzzing effort.

First, I identified a few entry points in `tls_sw.c`: `tls_sw_sendmsg`, `tls_sw_recvmsg`, `tls_sw_splice_read`, and `tls_sw_read_sock`. They're not static functions, so should have distinct symbols in vmlinux.

The prompt specifically mentions that static functions, *especially* inline ones, are problematic, but static functions *in .c files*, that *aren't* static inline, are good because they are usually in the symbol table.  Let me review the functions I've gathered.

From `net/tls/tls_sw.c` I have a few promising candidates: `tls_rx_rec_wait`, `tls_sw_sendmsg` (and `tls_sw_sendmsg_locked`), `tls_sw_recvmsg`, `tls_encrypt_done`, and `bpf_exec_tx_verdict`.  Then, there's `tls_device_sendmsg` from `net/tls/tls_device.c`, `sock_dequeue_err_skb` from `net/core/skbuff.c`, `strp_abort_strp` and `strp_recv` from `net/strparser/strparser.c`, and finally `sk_psock_backlog` from `net/core/skmsg.c`.

Now, let's determine if they are specific. `sock_dequeue_err_skb` is only called when reading from socket error queue, therefore is specific and looks good. The other `tls_sw` and `tls_device` functions are clearly related to kTLS software and device operations, so they look good too.  `strp_recv` is specific to the strparser functionality, and `sk_psock_backlog` is specific to the sockmap/psock backlog.

Next, I need to figure out what config options enable the code I'm targeting. I have: `CONFIG_TLS` (for `net/tls/tls_sw.o`), `CONFIG_TLS_DEVICE` (for `net/tls/tls_device.o`), `CONFIG_STREAM_PARSER` (for `net/strparser/strparser.o`), `CONFIG_NET_SOCK_MSG` (for `net/core/skmsg.o`), and `CONFIG_NET` (for `net/core/skbuff.c`).

Wait, the prompt says the configs need to be added to `EnableConfigs` and I recall some configs do not have a prompt to set them, e.g. `CONFIG_STREAM_PARSER` in `net/strparser/Kconfig`. It can be `n` unless selected by another option, so I need to be careful.  The Kconfig documentation says to check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed.

So, I think I'll focus on `TLS`, `TLS_DEVICE` and the config options that enable `STREAM_PARSER`, specifically.  `BPF_STREAM_PARSER`, `AF_KCM`, or `INET_ESPINTCP`.
I need to be *absolutely* sure that setting a config option with no prompt is valid. I'll need to double check the syzkaller documentation and Kconfig.

{
  "Expression": "config BPF_STREAM_PARSER",
  "PathPrefixes": [
    "net/Kconfig"
  ]
}

{
  "Output": "net/Kconfig=353=config BQL\n--\nnet/Kconfig-359-\nnet/Kconfig:360:config BPF_STREAM_PARSER\nnet/Kconfig-361-\tbool \"enable BPF STREAM_PARSER\"\n"
}

gemini-3.8-flash

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							input: 28476
							output: 32
							thoughts: 17
						

Okay, let's dive into this. Here's my summary, taking the first-person perspective as requested:

**Navigating the Kconfig Labyrinth**

Alright, time to get my hands dirty. I need to understand something specific, and I'm pretty sure the configuration files are where the answers lie. Let's see... based on my understanding of this system, `net/Kconfig` is probably the file I'm looking for, and around line 360 is a likely candidate. I'll need to open that up and see what I can find. Hopefully, the information I need is right there, clearly documented and easily interpretable within the context of the larger network configuration framework. Time to get started! Let's see what gems are waiting to be uncovered.

{
  "File": "net/Kconfig",
  "FirstLine": 355,
  "LineCount": 20
}

{
  "Contents": " 355:\t\tprompt \"Enable Byte Queue Limits\"\n 356:\t\tdepends on SYSFS\n 357:\t\tselect DQL\n 358:\t\tdefault y\n 359:\t\n 360:\tconfig BPF_STREAM_PARSER\n 361:\t\tbool \"enable BPF STREAM_PARSER\"\n 362:\t\tdepends on INET\n 363:\t\tdepends on BPF_SYSCALL\n 364:\t\tdepends on CGROUP_BPF\n 365:\t\tselect STREAM_PARSER\n 366:\t\tselect NET_SOCK_MSG\n 367:\t\thelp\n 368:\t\t  Enabling this allows a TCP stream parser to be used with\n 369:\t\t  BPF_MAP_TYPE_SOCKMAP.\n 370:\t\n 371:\tconfig NET_FLOW_LIMIT\n 372:\t\tbool \"Net flow limit\"\n 373:\t\tdepends on RPS\n 374:\t\tdefault y\n"
}

gemini-3.8-flash

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							input: 28951
							output: 31
							thoughts: 149
						

**My Configuration Deep Dive**

Okay, so I'm looking at these kernel configurations and trying to understand their dependencies. It seems like `BPF_STREAM_PARSER` is pulling in `STREAM_PARSER` and `NET_SOCK_MSG` – that makes sense, and it's what I expected. The `TLS` configuration also appears to require `NET_SOCK_MSG`, which is logical. Just to be thorough, I'm going to quickly glance at `AF_KCM`, and yep, it too is selecting `STREAM_PARSER`. I can skip `NET` and `INET` as those are pretty standard.

Now I need to list what configurations are actually required: `TLS`, `TLS_DEVICE`, `BPF_STREAM_PARSER`, `NET_SOCK_MSG`, and finally, `STREAM_PARSER` itself.

Alright, now I need to dive into `NET_SOCK_MSG` itself, time to check `net/Kconfig`.

{
  "Expression": "config NET_SOCK_MSG",
  "PathPrefixes": [
    "net/Kconfig"
  ]
}

{
  "Output": "net/Kconfig=474=config NET_SELFTESTS\n--\nnet/Kconfig-477-\nnet/Kconfig:478:config NET_SOCK_MSG\nnet/Kconfig-479-\tbool\n"
}

gemini-3.8-flash

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							input: 29409
							output: 245
							thoughts: 1307
						

**Analysis of Code Changes and Focus Symbol Selection**

Okay, so I've got this patch set to review, and the first thing I'm noting is the dependency structure. It looks like `NET_SOCK_MSG` is a direct result of enabling either `TLS` or `BPF_STREAM_PARSER`. So, if both those features are enabled, then, automatically, `NET_SOCK_MSG` and `STREAM_PARSER` are selected. By including `TLS`, `TLS_DEVICE`, and `BPF_STREAM_PARSER`, along with optional `STREAM_PARSER`, and `NET_SOCK_MSG`, we should have complete code coverage.

Now, the core of this is identifying the critical functions, the "FocusSymbols" as I call them. Based on the modifications, the affected functions or their direct callers/entrypoints seem to be: `sock_dequeue_err_skb`, `tls_rx_rec_wait`, `tls_sw_recvmsg`, `tls_sw_sendmsg`, `tls_sw_sendmsg_locked`, `tls_encrypt_done`, `bpf_exec_tx_verdict`, `tls_push_data`, `tls_device_sendmsg`, `strp_abort_strp`, and `sk_psock_backlog`.

Let's dive deeper. `tls_encrypt_done` - is it widely used? No, it's specific to the async crypto aspect of kTLS, so it needs to be included. Are `tls_sw_recvmsg` and `tls_sw_sendmsg` ubiquitous? No, they are only invoked for sockets running the TLS ULP! What about `sock_dequeue_err_skb`? It's only called when we read the error queue. `sk_psock_backlog`? Only for psock/sockmap backlog processing.

Now, let's examine these functions for the possibility of inlining. `sock_dequeue_err_skb` is EXPORT_SYMBOL, so no. `tls_sw_sendmsg` looks to be an exported symbol, or it's referenced in proto ops, so it won't be inlined. `tls_sw_recvmsg` is also in proto ops, so it's out. `tls_device_sendmsg` is another proto ops. `tls_rx_rec_wait` is static, so let's look at the source; it's called from several places; looking at line 1100 of `tls_sw.c`, it's not a static inline or __always_inline; it has a loop and waiting logic, and GCC is unlikely to inline it. `tls_sw_sendmsg_locked` is static, called from `tls_sw_sendmsg` and `tls_sw_sendpage_locked`. `tls_encrypt_done` is an async callback pointer; its address is taken, so it cannot be inlined. `bpf_exec_tx_verdict` is static, and it's called in three places. `strp_abort_strp` is static, too. `strp_recv` is exported as a function pointer.

Considering the coverage of both modified functions and their callers, that list seems solid. We want full coverage without needless dilution. So, the best set of FocusSymbols is:

*   `sock_dequeue_err_skb`
*   `tls_rx_rec_wait`
*   `tls_sw_recvmsg`
*   `tls_sw_sendmsg`
*   `tls_sw_sendmsg_locked`
*   `tls_encrypt_done`
*   `bpf_exec_tx_verdict`
*   `tls_push_data`
*   `tls_device_sendmsg`
*   `strp_abort_strp`
*   `sk_psock_backlog`

Just to make sure, let's look at the diff. I see `sk_psock_report_error` being called in `sk_psock_backlog`, then `sock_dequeue_err_skb` in net/core/skbuff.c, `strp_abort_strp` in strparser, and `tls_push_data` in tls_device. Everything matches the analysis!

The essential configuration elements are confirmed: `TLS`, `TLS_DEVICE`, and `BPF_STREAM_PARSER`.

Given the nature of these modifications, which touch error handling, and concurrency in the networking core, kTLS, and strparser subsystems, I'm marking this `WorthFuzzing: true`. Fuzzing will allow us to check the logic, especially with concurrent operations, asynchronous crypto

{
  "EnableConfigs": [
    "TLS",
    "TLS_DEVICE",
    "BPF_STREAM_PARSER"
  ],
  "FocusSymbols": [
    "sock_dequeue_err_skb",
    "tls_rx_rec_wait",
    "tls_sw_recvmsg",
    "tls_sw_sendmsg",
    "tls_sw_sendmsg_locked",
    "tls_encrypt_done",
    "bpf_exec_tx_verdict",
    "tls_push_data",
    "tls_device_sendmsg",
    "strp_abort_strp",
    "sk_psock_backlog"
  ],
  "Reasoning": "The patch alters socket error reporting and concurrency handling (READ_ONCE/WRITE_ONCE and sock_error() consumption) for sk-\u003esk_err across kTLS, socket error queue dequeueing, strparser, and psock. These changes affect reachable core networking and kTLS paths that can be exercised via user-space socket calls. Fuzzing is warranted to test for race conditions, unexpected error propagation, or state corruption.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "TLS",
    "TLS_DEVICE",
    "BPF_STREAM_PARSER"
  ],
  "FocusSymbols": [
    "sock_dequeue_err_skb",
    "tls_rx_rec_wait",
    "tls_sw_recvmsg",
    "tls_sw_sendmsg",
    "tls_sw_sendmsg_locked",
    "tls_encrypt_done",
    "bpf_exec_tx_verdict",
    "tls_push_data",
    "tls_device_sendmsg",
    "strp_abort_strp",
    "sk_psock_backlog"
  ],
  "Reasoning": "The patch alters socket error reporting and concurrency handling (READ_ONCE/WRITE_ONCE and sock_error() consumption) for sk-\u003esk_err across kTLS, socket error queue dequeueing, strparser, and psock. These changes affect reachable core networking and kTLS paths that can be exercised via user-space socket calls. Fuzzing is warranted to test for race conditions, unexpected error propagation, or state corruption.",
  "WorthFuzzing": true
}

{
  "WorthFuzzing": true
}

null

core

null

{
  "KMSANReasoning": "The patch addresses data races on `sk-\u003esk_err` by adding `READ_ONCE()` and `WRITE_ONCE()` annotations and refactoring error handling in TLS, strparser, and core skbuff routines.\n\nKMSAN is specifically designed to track and detect uninitialized memory reads and information leaks of uninitialized kernel memory to userspace. This patch does not introduce any uninitialized memory risks:\n1. No new stack or heap allocations, complex structs, or padding fields are introduced.\n2. The local helper variables introduced (`skerr`, `rc`) are explicitly initialized before evaluation.\n3. Socket structures and `sk-\u003esk_err` are fully initialized at socket creation time.\n4. No data copying to user space or length/bound calculations are modified in a manner that could expose uninitialized buffer contents.\n\nThe concurrency and data-race bugs targeted by this patch fall within the scope of KCSAN, and pointer/lifetime safety falls under KASAN. A dedicated KMSAN fuzzing session is not warranted.",
  "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.

Target architecture: amd64

For your convenience, here is the diff of the changes:
commit 81eb749005a44840efc46fa7f5abd086c7d9b464
Author: syz-cluster <triage@syzkaller.com>
Date:   Fri Oct 16 07:13:18 2026 +0000

    syz-cluster: applied patch under review

diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index d5e35f24738d5..52ce45f25f5a6 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -429,7 +429,7 @@ static inline void sk_psock_report_error(struct sk_psock *psock, int err)
 {
 	struct sock *sk = psock->sk;
 
-	sk->sk_err = err;
+	WRITE_ONCE(sk->sk_err, err);
 	sk_error_report(sk);
 }
 
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index d56f4f0102f75..a6c9cf57bc3bf 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -5539,12 +5539,13 @@ struct sk_buff *sock_dequeue_err_skb(struct sock *sk)
 	if (skb && (skb_next = skb_peek(q))) {
 		icmp_next = is_icmp_err_skb(skb_next);
 		if (icmp_next)
-			sk->sk_err = SKB_EXT_ERR(skb_next)->ee.ee_errno;
+			WRITE_ONCE(sk->sk_err,
+				   SKB_EXT_ERR(skb_next)->ee.ee_errno);
 	}
 	spin_unlock_irqrestore(&q->lock, flags);
 
 	if (is_icmp_err_skb(skb) && !icmp_next)
-		sk->sk_err = 0;
+		WRITE_ONCE(sk->sk_err, 0);
 
 	if (skb_next)
 		sk_error_report(sk);
diff --git a/net/strparser/strparser.c b/net/strparser/strparser.c
index 9c1559d7923f2..5f1da32b152fc 100644
--- a/net/strparser/strparser.c
+++ b/net/strparser/strparser.c
@@ -56,7 +56,7 @@ static void strp_abort_strp(struct strparser *strp, int err)
 	strp->need_bytes = 0;
 
 	/* Report an error on the lower socket */
-	sk->sk_err = -err;
+	WRITE_ONCE(sk->sk_err, -err);
 	sk_error_report(sk);
 }
 
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index f11d0528fc431..03ce83a9d4e9c 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -444,8 +444,9 @@ static int tls_push_data(struct sock *sk,
 	if ((flags & (MSG_MORE | MSG_EOR)) == (MSG_MORE | MSG_EOR))
 		return -EINVAL;
 
-	if (unlikely(sk->sk_err))
-		return -sk->sk_err;
+	rc = -READ_ONCE(sk->sk_err);
+	if (unlikely(rc))
+		return rc;
 
 	flags |= MSG_SENDPAGE_DECRYPTED;
 	tls_push_record_flags = flags | MSG_MORE;
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 312e51270f293..4221b2ad3c1d3 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -473,6 +473,7 @@ static void tls_encrypt_done(void *data, int err)
 	struct scatterlist *sge;
 	struct sk_msg *msg_en;
 	struct sock *sk;
+	int skerr;
 
 	if (err == -EINPROGRESS) /* see the comment in tls_decrypt_done() */
 		return;
@@ -488,13 +489,15 @@ static void tls_encrypt_done(void *data, int err)
 	sge->offset -= prot->prepend_size;
 	sge->length += prot->prepend_size;
 
+	skerr = READ_ONCE(sk->sk_err);
+
 	/* Check if error is previously set on socket */
-	if (err || sk->sk_err) {
+	if (err || skerr) {
 		rec = NULL;
 
 		/* If err is already set on socket, return the same code */
-		if (sk->sk_err) {
-			ctx->async_wait.err = -sk->sk_err;
+		if (skerr) {
+			ctx->async_wait.err = -skerr;
 		} else {
 			ctx->async_wait.err = err;
 			tls_err_abort(sk, err);
@@ -701,13 +704,17 @@ static int tls_push_record(struct sock *sk, int flags,
 static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 			       u8 record_type, ssize_t *copied, int flags)
 {
+	int skerr;
 	int err;
 
 	err = tls_push_record(sk, flags, record_type);
-	if (err && err != -EINPROGRESS && sk->sk_err == EBADMSG) {
-		*copied -= sk_msg_free(sk, msg);
-		tls_free_open_rec(sk);
-		err = -sk->sk_err;
+	if (err && err != -EINPROGRESS) {
+		skerr = READ_ONCE(sk->sk_err);
+		if (skerr == EBADMSG) {
+			*copied -= sk_msg_free(sk, msg);
+			tls_free_open_rec(sk);
+			err = -skerr;
+		}
 	}
 	return err;
 }
@@ -800,10 +807,9 @@ static int tls_sw_sendmsg_locked(struct sock *sk, struct msghdr *msg,
 	}
 
 	while (msg_data_left(msg)) {
-		if (sk->sk_err) {
-			ret = -sk->sk_err;
+		ret = -READ_ONCE(sk->sk_err);
+		if (ret)
 			goto send_end;
-		}
 
 		if (ctx->open_rec)
 			rec = ctx->open_rec;
@@ -1098,6 +1104,7 @@ tls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 	int ret = 0;
+	int skerr;
 	long timeo;
 
 	/* a rekey is pending, let userspace deal with it */
@@ -1107,10 +1114,14 @@ tls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)
 	timeo = sock_rcvtimeo(sk, nonblock);
 
 	while (!tls_strp_msg_ready(ctx)) {
-		if (sk->sk_err) {
-			if (has_copied)
-				return -READ_ONCE(sk->sk_err);
-			return sock_error(sk);
+		if (has_copied) {
+			skerr = READ_ONCE(sk->sk_err);
+			if (skerr)
+				return -skerr;
+		} else {
+			skerr = sock_error(sk);
+			if (skerr)
+				return skerr;
 		}
 
 		if (ret < 0)
@@ -1132,10 +1143,14 @@ tls_rx_rec_wait(struct sock *sk, bool nonblock, bool released, bool has_copied)
 		 * sk_err here so a connection abort surfaces as the
 		 * actual error rather than a clean EOF.
 		 */
-		if (sk->sk_err) {
-			if (has_copied)
-				return -READ_ONCE(sk->sk_err);
-			return sock_error(sk);
+		if (has_copied) {
+			skerr = READ_ONCE(sk->sk_err);
+			if (skerr)
+				return -skerr;
+		} else {
+			skerr = sock_error(sk);
+			if (skerr)
+				return skerr;
 		}
 		if (sk->sk_shutdown & RCV_SHUTDOWN)
 			return 0;

gemini-3.8-flash

null

null

							input: 4368
							output: 241
							thoughts: 1572
						

**Analysis of the Socket Error Patch**

Okay, let's break down this patch. My initial assessment is that it's focused on protecting `sk->sk_err` from data races. The patch modifies several files, primarily in the networking stack, specifically those related to TLS and core socket functionality. The changes revolve around consistently using `READ_ONCE` and `WRITE_ONCE` when accessing `sk->sk_err`. This immediately signals to me that the primary goal is to address potential race conditions where multiple threads or CPUs might be reading or writing to this field concurrently without proper synchronization. I'm seeing changes in `sk_psock_report_error()`, `sock_dequeue_err_skb()`, `strp_abort_strp()`, `tls_device.c`, and several functions within `tls_sw.c` like `tls_encrypt_done()`, `bpf_exec_tx_verdict()`, `tls_sw_sendmsg_locked()`, and `tls_rx_rec_wait()`. It looks like the patch is cleaning up and making the error handling logic more robust by using `READ_ONCE` everywhere `sk->sk_err` is read and using it consistently in the error propagation paths.

Now, my key concern as an expert in this area is uninitialized memory. Does this patch introduce a risk of reading uninitialized values? No, because `sk->sk_err` is a field within `struct sock`. `struct sock` is allocated and zeroed during socket creation via `sk_alloc`. The patch itself just adds `READ_ONCE` / `WRITE_ONCE` or cleans up how the error code is read and tested. It doesn't modify the socket structure's layout or the initialization process. Also I don't see any changes to memory allocations, conditional logic, or bounds checks that could lead to reading uninitialized data. In functions like `tls_rx_rec_wait` where there were potential race conditions on reading the error status, the patch ensures the error code is read only once to a local variable (`skerr`) before any checks are performed. That means `skerr` is always initialized before use.

In summary, this patch is only focused on addressing data races, which is the domain of KCSAN. This patch does *not* introduce any new uninitialized memory risks. Thus, `NeedsKMSAN = false`. We don't need to involve KMSAN (Kernel Memory Sanitizer) here, since it's designed to detect uninitialized memory reads. KASAN (Kernel Address Sanitizer) isn't relevant either because there's no change to memory safety. KCSAN, however, is a good fit to check for data races which this patch is fixing. My reasoning is solid. I'm going to set-results.

{
  "KMSANReasoning": "The patch addresses data races on `sk-\u003esk_err` by adding `READ_ONCE()` and `WRITE_ONCE()` annotations and refactoring error handling in TLS, strparser, and core skbuff routines.\n\nKMSAN is specifically designed to track and detect uninitialized memory reads and information leaks of uninitialized kernel memory to userspace. This patch does not introduce any uninitialized memory risks:\n1. No new stack or heap allocations, complex structs, or padding fields are introduced.\n2. The local helper variables introduced (`skerr`, `rc`) are explicitly initialized before evaluation.\n3. Socket structures and `sk-\u003esk_err` are fully initialized at socket creation time.\n4. No data copying to user space or length/bound calculations are modified in a manner that could expose uninitialized buffer contents.\n\nThe concurrency and data-race bugs targeted by this patch fall within the scope of KCSAN, and pointer/lifetime safety falls under KASAN. A dedicated KMSAN fuzzing session is not warranted.",
  "NeedsKMSAN": false
}

{
  "KMSANReasoning": "The patch addresses data races on `sk-\u003esk_err` by adding `READ_ONCE()` and `WRITE_ONCE()` annotations and refactoring error handling in TLS, strparser, and core skbuff routines.\n\nKMSAN is specifically designed to track and detect uninitialized memory reads and information leaks of uninitialized kernel memory to userspace. This patch does not introduce any uninitialized memory risks:\n1. No new stack or heap allocations, complex structs, or padding fields are introduced.\n2. The local helper variables introduced (`skerr`, `rc`) are explicitly initialized before evaluation.\n3. Socket structures and `sk-\u003esk_err` are fully initialized at socket creation time.\n4. No data copying to user space or length/bound calculations are modified in a manner that could expose uninitialized buffer contents.\n\nThe concurrency and data-race bugs targeted by this patch fall within the scope of KCSAN, and pointer/lifetime safety falls under KASAN. A dedicated KMSAN fuzzing session is not warranted.",
  "NeedsKMSAN": false
}