AI Trajectory

null

{
  "EnableConfigs": [
    "BPF_SYSCALL"
  ],
  "FocusSymbols": [
    "tcp_bpf_ioctl"
  ],
  "Reasoning": "The patch fixes the SIOCINQ (FIONREAD) ioctl for TCP sockets attached to a BPF sockmap without a verdict program. It modifies `tcp_bpf_ioctl` to correctly account for data in `sk_receive_queue` when no verdict program is attached. This is a functional change in core network/BPF logic that can be reached from user space via ioctl.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit 55aa5f7eb8b447242c07be65bb4ea7958e20a38d\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Thu Jul 9 06:38:22 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c\nindex cc0bd73f36b6d6..8e905b50deadbe 100644\n--- a/net/ipv4/tcp_bpf.c\n+++ b/net/ipv4/tcp_bpf.c\n@@ -334,6 +334,7 @@ static int tcp_bpf_recvmsg_parser(struct sock *sk,\n \n static int tcp_bpf_ioctl(struct sock *sk, int cmd, int *karg)\n {\n+\tstruct sk_psock *psock;\n \tbool slow;\n \n \tif (cmd != SIOCINQ)\n@@ -344,7 +345,21 @@ static int tcp_bpf_ioctl(struct sock *sk, int cmd, int *karg)\n \t\treturn -EINVAL;\n \n \tslow = lock_sock_fast(sk);\n-\t*karg = sk_psock_msg_inq(sk);\n+\tpsock = sk_psock_get(sk);\n+\tif (unlikely(!psock)) {\n+\t\tunlock_sock_fast(sk, slow);\n+\t\treturn tcp_ioctl(sk, cmd, karg);\n+\t}\n+\t*karg = sk_psock_get_msg_len_nolock(psock);\n+\t/* Without a verdict program, ingress data is never diverted to\n+\t * ingress_msg: it stays in sk_receive_queue and is read through\n+\t * the fallback to tcp_recvmsg(), so account for it like\n+\t * tcp_ioctl() does.\n+\t */\n+\tif (!READ_ONCE(psock-\u003eprogs.stream_verdict) \u0026\u0026\n+\t    !READ_ONCE(psock-\u003eprogs.skb_verdict))\n+\t\t*karg += tcp_inq(sk);\n+\tsk_psock_put(sk, psock);\n \tunlock_sock_fast(sk, slow);\n \n \treturn 0;\ndiff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c\nindex cb3229711f93a3..f0f368201ddadb 100644\n--- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c\n+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c\n@@ -1373,6 +1373,43 @@ static void test_sockmap_multi_channels(int sotype)\n \ttest_sockmap_pass_prog__destroy(skel);\n }\n \n+/* A socket in a sockmap without a verdict program keeps its ingress data\n+ * in sk_receive_queue: FIONREAD must account for it.\n+ */\n+static void test_sockmap_no_verdict_fionread(void)\n+{\n+\tint err, map, zero = 0, sent, avail;\n+\tint c0 = -1, c1 = -1, p0 = -1, p1 = -1;\n+\tstruct test_sockmap_pass_prog *skel;\n+\tchar buf[256] = \"0123456789\";\n+\n+\tskel = test_sockmap_pass_prog__open_and_load();\n+\tif (!ASSERT_OK_PTR(skel, \"open_and_load\"))\n+\t\treturn;\n+\tmap = bpf_map__fd(skel-\u003emaps.sock_map_rx);\n+\n+\terr = create_socket_pairs(AF_INET, SOCK_STREAM, \u0026c0, \u0026c1, \u0026p0, \u0026p1);\n+\tif (!ASSERT_OK(err, \"create_socket_pairs()\"))\n+\t\tgoto out;\n+\n+\terr = bpf_map_update_elem(map, \u0026zero, \u0026c1, BPF_NOEXIST);\n+\tif (!ASSERT_OK(err, \"bpf_map_update_elem(c1)\"))\n+\t\tgoto out_close;\n+\n+\tsent = xsend(p1, \u0026buf, sizeof(buf), 0);\n+\tASSERT_EQ(sent, sizeof(buf), \"xsend(p1)\");\n+\tavail = wait_for_fionread(c1, sizeof(buf), IO_TIMEOUT_SEC);\n+\tASSERT_EQ(avail, sizeof(buf), \"ioctl(FIONREAD)\");\n+\n+out_close:\n+\tclose(c0);\n+\tclose(p0);\n+\tclose(c1);\n+\tclose(p1);\n+out:\n+\ttest_sockmap_pass_prog__destroy(skel);\n+}\n+\n void test_sockmap_basic(void)\n {\n \tif (test__start_subtest(\"sockmap create_update_free\"))\n@@ -1415,6 +1452,8 @@ void test_sockmap_basic(void)\n \t\ttest_sockmap_skb_verdict_shutdown();\n \tif (test__start_subtest(\"sockmap skb_verdict fionread\"))\n \t\ttest_sockmap_skb_verdict_fionread(true);\n+\tif (test__start_subtest(\"sockmap no_verdict fionread\"))\n+\t\ttest_sockmap_no_verdict_fionread();\n \tif (test__start_subtest(\"sockmap skb_verdict fionread on drop\"))\n \t\ttest_sockmap_skb_verdict_fionread(false);\n \tif (test__start_subtest(\"sockmap skb_verdict change tail\"))\n"
}

gemini-3.1-pro-preview

null

{
  "EnableConfigs": [
    "BPF_SYSCALL"
  ],
  "FocusSymbols": [
    "tcp_bpf_ioctl"
  ],
  "Reasoning": "The patch fixes the SIOCINQ (FIONREAD) ioctl for TCP sockets attached to a BPF sockmap without a verdict program. It modifies `tcp_bpf_ioctl` to correctly account for data in `sk_receive_queue` when no verdict program is attached. This is a functional change in core network/BPF logic that can be reached from user space via ioctl.",
  "WorthFuzzing": true
}

You are an expert Linux kernel maintainer.
Your job is to review a provided patch series and determine
if it makes functional changes to the kernel that should be fuzzed.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively
use your code access tools to examine the actual source code and confirm any assumptions.

Return WorthFuzzing=false if the patch only contains:
- Modifications to Documentation/, Kconfig files, or code comments.
- Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints.
- Changes to numeric constants or macros that do not functionally alter execution flow.
- Code paths that are impossible to reach in virtualized environments like GCE or QEMU,
even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim).

If it modifies reachable core kernel logic, drivers, or architectures, use your code search
tools to verify the code can be executed, then return WorthFuzzing=true.

When returning WorthFuzzing=true, you MUST ALSO:
1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols.
   Avoid listing generic hot-path functions to prevent skewed test distributions.
2. Identify any specific CONFIG_ options required to properly test this new/modified feature.
   Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions.
   Do not list too generic configs (we already have them enabled). Only list those that
   specifically cover the modified code. List them in the EnableConfigs output array,
   and DO NOT add a 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4").
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

For your convenience, here is the diff of the changes:
commit 55aa5f7eb8b447242c07be65bb4ea7958e20a38d
Author: syz-cluster <triage@syzkaller.com>
Date:   Thu Jul 9 06:38:22 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index cc0bd73f36b6d6..8e905b50deadbe 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -334,6 +334,7 @@ static int tcp_bpf_recvmsg_parser(struct sock *sk,
 
 static int tcp_bpf_ioctl(struct sock *sk, int cmd, int *karg)
 {
+	struct sk_psock *psock;
 	bool slow;
 
 	if (cmd != SIOCINQ)
@@ -344,7 +345,21 @@ static int tcp_bpf_ioctl(struct sock *sk, int cmd, int *karg)
 		return -EINVAL;
 
 	slow = lock_sock_fast(sk);
-	*karg = sk_psock_msg_inq(sk);
+	psock = sk_psock_get(sk);
+	if (unlikely(!psock)) {
+		unlock_sock_fast(sk, slow);
+		return tcp_ioctl(sk, cmd, karg);
+	}
+	*karg = sk_psock_get_msg_len_nolock(psock);
+	/* Without a verdict program, ingress data is never diverted to
+	 * ingress_msg: it stays in sk_receive_queue and is read through
+	 * the fallback to tcp_recvmsg(), so account for it like
+	 * tcp_ioctl() does.
+	 */
+	if (!READ_ONCE(psock->progs.stream_verdict) &&
+	    !READ_ONCE(psock->progs.skb_verdict))
+		*karg += tcp_inq(sk);
+	sk_psock_put(sk, psock);
 	unlock_sock_fast(sk, slow);
 
 	return 0;
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
index cb3229711f93a3..f0f368201ddadb 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
@@ -1373,6 +1373,43 @@ static void test_sockmap_multi_channels(int sotype)
 	test_sockmap_pass_prog__destroy(skel);
 }
 
+/* A socket in a sockmap without a verdict program keeps its ingress data
+ * in sk_receive_queue: FIONREAD must account for it.
+ */
+static void test_sockmap_no_verdict_fionread(void)
+{
+	int err, map, zero = 0, sent, avail;
+	int c0 = -1, c1 = -1, p0 = -1, p1 = -1;
+	struct test_sockmap_pass_prog *skel;
+	char buf[256] = "0123456789";
+
+	skel = test_sockmap_pass_prog__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_and_load"))
+		return;
+	map = bpf_map__fd(skel->maps.sock_map_rx);
+
+	err = create_socket_pairs(AF_INET, SOCK_STREAM, &c0, &c1, &p0, &p1);
+	if (!ASSERT_OK(err, "create_socket_pairs()"))
+		goto out;
+
+	err = bpf_map_update_elem(map, &zero, &c1, BPF_NOEXIST);
+	if (!ASSERT_OK(err, "bpf_map_update_elem(c1)"))
+		goto out_close;
+
+	sent = xsend(p1, &buf, sizeof(buf), 0);
+	ASSERT_EQ(sent, sizeof(buf), "xsend(p1)");
+	avail = wait_for_fionread(c1, sizeof(buf), IO_TIMEOUT_SEC);
+	ASSERT_EQ(avail, sizeof(buf), "ioctl(FIONREAD)");
+
+out_close:
+	close(c0);
+	close(p0);
+	close(c1);
+	close(p1);
+out:
+	test_sockmap_pass_prog__destroy(skel);
+}
+
 void test_sockmap_basic(void)
 {
 	if (test__start_subtest("sockmap create_update_free"))
@@ -1415,6 +1452,8 @@ void test_sockmap_basic(void)
 		test_sockmap_skb_verdict_shutdown();
 	if (test__start_subtest("sockmap skb_verdict fionread"))
 		test_sockmap_skb_verdict_fionread(true);
+	if (test__start_subtest("sockmap no_verdict fionread"))
+		test_sockmap_no_verdict_fionread();
 	if (test__start_subtest("sockmap skb_verdict fionread on drop"))
 		test_sockmap_skb_verdict_fionread(false);
 	if (test__start_subtest("sockmap skb_verdict change tail"))

gemini-3.1-pro-preview

null

null

							input: 3037
							output: 37
							thoughts: 240
						

**Analyzing a Core Network/BPF Patch**

Okay, so I'm looking at a patch that's touching `net/ipv4/tcp_bpf.c`, specifically, the `tcp_bpf_ioctl` function. And it seems to involve a selftest in `tools/testing/selftests/bpf/prog_tests/sockmap_basic.c`. My gut feeling is this is going to be important for BPF-based socket mapping, especially considering the file names. This is likely a functional change, not just a cosmetic one. The core logic of how `SIOCINQ` (aka FIONREAD), which gives information about the amount of data that can be read from the socket, is being handled for TCP sockets attached to BPF sockmaps.

I see it's using things like `sk_psock_get(sk)`, `sk_psock_get_msg_len_nolock(psock)`, and checking `psock->progs.stream_verdict` and `psock->progs.skb_verdict`. Right, so this is about how the BPF programs attached to the socket map are influencing the data available. If there's no verdict program attached, the patch adds `tcp_inq(sk)` to the result. That's a critical point to note, a fallback mechanism, I'd need to consider edge cases and whether this is the optimal default.

I need to dive into `tcp_bpf_ioctl` now, understand exactly how this affects the control path. Let's fire up `grepper` and see where this function is called and what kernel config options are needed to enable it. This will help me understand the scope of the change and what dependencies are in play. I need to be sure any modifications are well-integrated and don't introduce unintended side-effects.

{
  "Expression": "tcp_bpf_ioctl",
  "PathPrefix": "net/ipv4/tcp_bpf.c"
}

{
  "Output": "net/ipv4/tcp_bpf.c=221=static int tcp_bpf_recvmsg_parser(struct sock *sk,\n--\nnet/ipv4/tcp_bpf.c-334-\nnet/ipv4/tcp_bpf.c:335:static int tcp_bpf_ioctl(struct sock *sk, int cmd, int *karg)\nnet/ipv4/tcp_bpf.c-336-{\n--\nnet/ipv4/tcp_bpf.c=638=static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS],\n--\nnet/ipv4/tcp_bpf.c-645-\tprot[TCP_BPF_BASE].sock_is_readable\t= sk_msg_is_readable;\nnet/ipv4/tcp_bpf.c:646:\tprot[TCP_BPF_BASE].ioctl\t\t= tcp_bpf_ioctl;\nnet/ipv4/tcp_bpf.c-647-\n"
}

gemini-3.1-pro-preview

null

null

							input: 3975
							output: 32
							thoughts: 61
						

Okay, let's see what's going on here.

**BPF Sockmap and TCP: Dissecting `tcp_bpf_ioctl`**

Alright, so `tcp_bpf_ioctl` is getting slotted into `prot[TCP_BPF_BASE].ioctl`. That immediately tells me this is related to BPF sockmap functionality specifically for TCP. The name alone confirms that. Now, the natural next step is to dive into the core implementation. I need to understand the configuration requirements within `net/ipv4/tcp_bpf.c`. Time to see what kind of interactions it's designed for, the likely ioctl operations it supports, and how it fits into the broader BPF framework for TCP socket management. I need to get a handle on the necessary configuration options and data structures involved, and the potential implications for performance and security.

{
  "Expression": "tcp_bpf\\.o",
  "PathPrefix": "net/ipv4/Makefile"
}

{
  "Output": "net/ipv4/Makefile=62=obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o\nnet/ipv4/Makefile:63:obj-$(CONFIG_NET_SOCK_MSG) += tcp_bpf.o\nnet/ipv4/Makefile-64-obj-$(CONFIG_BPF_SYSCALL) += udp_bpf.o\n"
}

gemini-3.1-pro-preview

null

null

							input: 4352
							output: 20
							thoughts: 65
						

Okay, let's see, my initial observation is that `CONFIG_NET_SOCK_MSG` is definitely a prerequisite here. That makes sense, given what I'm working on. Now, a BPF-related system usually pulls in `CONFIG_BPF_SYSCALL` – it's practically a given. Therefore, I need to confirm both are set. Let me just quickly cross-reference `CONFIG_NET_SOCK_MSG`. I'll check the `net/Kconfig` file, or something equivalent, to verify the exact dependencies and implications.

{
  "Expression": "config NET_SOCK_MSG"
}

{
  "Output": "net/Kconfig=475=config NET_SELFTESTS\n--\nnet/Kconfig-478-\nnet/Kconfig:479:config NET_SOCK_MSG\nnet/Kconfig-480-\tbool\n"
}

gemini-3.1-pro-preview

null

null

							input: 4625
							output: 20
							thoughts: 43
						

Okay, here's my take on those thoughts, tailored for an expert audience, and written as if they were my own immediate processing:

**Digging into NET_SOCK_MSG's Selection**

Alright, so `NET_SOCK_MSG`... that's a hidden bool, right? I'm pretty sure it's involved in some interesting eBPF interactions. I vaguely remember seeing it tied to both `BPF_SYSCALL` and `CGROUP_BPF` somehow. My initial hunch is that it's acting as some kind of filter or flag, but I need to quickly confirm what triggers this thing. Time to dive deeper and see what the selection criteria actually *are*. This is probably a pointer to understanding the overall control flow better. Let's see how and *why* it gets selected.

{
  "Expression": "select NET_SOCK_MSG"
}

{
  "Output": "kernel/bpf/Kconfig=27=config BPF_SYSCALL\n--\nkernel/bpf/Kconfig-33-\tselect BINARY_PRINTF\nkernel/bpf/Kconfig:34:\tselect NET_SOCK_MSG if NET\nkernel/bpf/Kconfig-35-\tselect NET_XGRESS if NET\n--\nnet/Kconfig=361=config BPF_STREAM_PARSER\n--\nnet/Kconfig-366-\tselect STREAM_PARSER\nnet/Kconfig:367:\tselect NET_SOCK_MSG\nnet/Kconfig-368-\thelp\n--\nnet/ipv4/Kconfig=382=config INET_ESPINTCP\n--\nnet/ipv4/Kconfig-385-\tselect STREAM_PARSER\nnet/ipv4/Kconfig:386:\tselect NET_SOCK_MSG\nnet/ipv4/Kconfig-387-\tselect XFRM_ESPINTCP\n--\nnet/ipv6/Kconfig=90=config INET6_ESPINTCP\n--\nnet/ipv6/Kconfig-93-\tselect STREAM_PARSER\nnet/ipv6/Kconfig:94:\tselect NET_SOCK_MSG\nnet/ipv6/Kconfig-95-\tselect XFRM_ESPINTCP\n--\nnet/tls/Kconfig=5=config TLS\n--\nnet/tls/Kconfig-10-\tselect CRYPTO_GCM\nnet/tls/Kconfig:11:\tselect NET_SOCK_MSG\nnet/tls/Kconfig-12-\tdefault n\n"
}

gemini-3.1-pro-preview

null

null

							input: 5257
							output: 41
							thoughts: 137
						

**My Assessment of the Proposed Changes**

Okay, so the core of this seems to be about integrating BPF syscalls with the networking stack, specifically around `NET_SOCK_MSG`. My initial thought is that enabling both `BPF_SYSCALL` and `NET` appears to be the right approach, assuming `NET` provides the necessary base functionality. The patch also touches `tcp_bpf_ioctl`, which immediately catches my attention. I need to understand the implications there.

My immediate question is, does this interact in any specific way with `sockmap`? Though, maybe `BPF_SYSCALL` covers it. I need to confirm. My focus now needs to be on the `tcp_bpf_ioctl` function.

I also see that `sk_psock_get_msg_len_nolock` is being called. That's another critical piece of the puzzle. I need to dig into `sk_psock_get_msg_len_nolock` to fully grasp the ramifications of this change. It is necessary to trace how this function works.

{
  "Expression": "sk_psock_get_msg_len_nolock",
  "PathPrefix": "include/linux/skmsg.h"
}

{
  "Output": "include/linux/skmsg.h=327=static inline void sock_drop(struct sock *sk, struct sk_buff *skb)\n--\ninclude/linux/skmsg.h-332-\ninclude/linux/skmsg.h:333:static inline u32 sk_psock_get_msg_len_nolock(struct sk_psock *psock)\ninclude/linux/skmsg.h-334-{\n--\ninclude/linux/skmsg.h=339=static inline void sk_psock_msg_len_add_locked(struct sk_psock *psock, int diff)\ninclude/linux/skmsg.h-340-{\ninclude/linux/skmsg.h:341:\t/* Use WRITE_ONCE to ensure correct read in sk_psock_get_msg_len_nolock().\ninclude/linux/skmsg.h-342-\t * ingress_lock should be held to prevent concurrent updates to msg_tot_len\n--\ninclude/linux/skmsg.h=555=static inline ssize_t sk_psock_msg_inq(struct sock *sk)\n--\ninclude/linux/skmsg.h-561-\tif (likely(psock)) {\ninclude/linux/skmsg.h:562:\t\tinq = sk_psock_get_msg_len_nolock(psock);\ninclude/linux/skmsg.h-563-\t\tsk_psock_put(sk, psock);\n"
}

gemini-3.1-pro-preview

null

null

							input: 6037
							output: 37
							thoughts: 40
						

Here's my take on the thought process, as requested:

**Diving Back into `tcp_bpf_ioctl`**

Okay, so this patch is touching `tcp_bpf_ioctl`, specifically within `net/ipv4/tcp_bpf.c`. That function's got my attention. It's the key interface for, well, interacting with BPF (Berkeley Packet Filter) within the TCP stack. The interaction likely has something to do with the specific change made by the patch. Given my expertise, I need to revisit that function with fresh eyes. I want to see how the changes are implemented and to fully grasp the ramifications for the BPF functionality. Let's dig in and re-examine its implementation.

{
  "Expression": "tcp_bpf_ioctl",
  "PathPrefix": "net/ipv4/tcp_bpf.c"
}

{
  "Output": "net/ipv4/tcp_bpf.c=221=static int tcp_bpf_recvmsg_parser(struct sock *sk,\n--\nnet/ipv4/tcp_bpf.c-334-\nnet/ipv4/tcp_bpf.c:335:static int tcp_bpf_ioctl(struct sock *sk, int cmd, int *karg)\nnet/ipv4/tcp_bpf.c-336-{\n--\nnet/ipv4/tcp_bpf.c=638=static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS],\n--\nnet/ipv4/tcp_bpf.c-645-\tprot[TCP_BPF_BASE].sock_is_readable\t= sk_msg_is_readable;\nnet/ipv4/tcp_bpf.c:646:\tprot[TCP_BPF_BASE].ioctl\t\t= tcp_bpf_ioctl;\nnet/ipv4/tcp_bpf.c-647-\n"
}

gemini-3.1-pro-preview

null

null

							input: 6533
							output: 22
							thoughts: 239
						

**My Assessment of the TCP BPF Sockmap Patch**

Okay, so this patch is aimed at fixing how `SIOCINQ` (FIONREAD), that's the "bytes waiting to be read" ioctl, works on TCP sockets connected to a BPF sockmap *without* a verdict program. That's a pretty specific scenario, but important nonetheless. It's a functional change, which means we need to treat it seriously. This means it needs fuzzing to ensure that it operates safely under all conditions, and that any edge cases are accounted for.

The core of the change seems to be within `tcp_bpf_ioctl`, and specifically how it handles the `sk_receive_queue` when there's no verdict program involved. So, `tcp_bpf_ioctl` is definitely the key symbol to focus on.

Let's look at the configs that are relevant here. `CONFIG_BPF_SYSCALL` is the big one, obviously. We'll need to double check to see if there are others. `CONFIG_NET` and `CONFIG_INET` are also needed, but those are pretty generic. I'm wondering if `CONFIG_BPF_STREAM_PARSER` plays a role here, because we're dealing with TCP sockets, and sockmaps, so let's delve into that one a bit deeper.

{
  "Expression": "config BPF_STREAM_PARSER"
}

{
  "Output": "net/Kconfig=354=config BQL\n--\nnet/Kconfig-360-\nnet/Kconfig:361:config BPF_STREAM_PARSER\nnet/Kconfig-362-\tbool \"enable BPF STREAM_PARSER\"\n"
}

gemini-3.1-pro-preview

null

null

							input: 7160
							output: 130
							thoughts: 473
						

**Analyzing TCP BPF Interaction**

Okay, let's break this down systematically. I need to understand the dependencies and hot paths for this `tcp_bpf` interaction. First, I need to make sure I understand the code.

My initial thought is to verify whether compiling `tcp_bpf.c` needs `BPF_STREAM_PARSER`. I quickly see that it's actually dependent on `NET_SOCK_MSG`. And that in turn is selected by `BPF_SYSCALL` if `NET` is set. So, `BPF_SYSCALL` seems to be sufficient for my purposes.

Next, I need to check if `tcp_bpf_ioctl` is a critical path. Since it's an ioctl, it's not a hot path, so this seems to be a good symbol to focus on.

Now, let me go through that patch to verify it again.
```c
static int tcp_bpf_ioctl(struct sock *sk, int cmd, int *karg)
{
	struct sk_psock *psock;
	bool slow;

	if (cmd != SIOCINQ)
		return -ENOIOCTLCMD;

	if (sk->sk_state == TCP_LISTEN)
		return -EINVAL;

	slow = lock_sock_fast(sk);
	psock = sk_psock_get(sk);
	if (unlikely(!psock)) {
		unlock_sock_fast(sk, slow);
		return tcp_ioctl(sk, cmd, karg);
	}
	*karg = sk_psock_get_msg_len_nolock(psock);
	/* Without a verdict program, ingress data is never diverted to
	 * ingress_msg: it stays in sk_receive_queue and is read through
	 * the fallback to tcp_recvmsg(), so account for it like
	 * tcp_ioctl() does.
	 */
	if (!READ_ONCE(psock->progs.stream_verdict) &&
	    !READ_ONCE(psock->progs.skb_verdict))
		*karg += tcp_inq(sk);
	sk_psock_put(sk, psock);
	unlock_sock_fast(sk, slow);

	return 0;
}
```
Yeah, the patch looks functional. I can now set the results.

{
  "EnableConfigs": [
    "BPF_SYSCALL"
  ],
  "FocusSymbols": [
    "tcp_bpf_ioctl"
  ],
  "Reasoning": "The patch fixes the SIOCINQ (FIONREAD) ioctl for TCP sockets attached to a BPF sockmap without a verdict program. It modifies `tcp_bpf_ioctl` to correctly account for data in `sk_receive_queue` when no verdict program is attached. This is a functional change in core network/BPF logic that can be reached from user space via ioctl.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "BPF_SYSCALL"
  ],
  "FocusSymbols": [
    "tcp_bpf_ioctl"
  ],
  "Reasoning": "The patch fixes the SIOCINQ (FIONREAD) ioctl for TCP sockets attached to a BPF sockmap without a verdict program. It modifies `tcp_bpf_ioctl` to correctly account for data in `sk_receive_queue` when no verdict program is attached. This is a functional change in core network/BPF logic that can be reached from user space via ioctl.",
  "WorthFuzzing": true
}