AI Trajectory

null

{
  "EnableConfigs": [
    "BPF_SYSCALL",
    "BPF_STREAM_PARSER"
  ],
  "FocusSymbols": [
    "tcp_bpf_send_verdict",
    "tcp_bpf_sendmsg",
    "tcp_bpf_sendmsg_redir"
  ],
  "Reasoning": "The patch fixes a potential use-after-free issue in `tcp_bpf_send_verdict` by holding a reference to `sk_redir` while it is being used. This is a functional change in the core BPF sockmap logic that is reachable from userspace and should be fuzzed.",
  "WorthFuzzing": true
}

null

{
  "PatchDiff": "commit 1d20ba607ddf2190525103e203b51244efa4f7da\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Sun Jul 19 16:04:50 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 8e905b50deadbe..69cc8bc33bcd1c 100644\n--- a/net/ipv4/tcp_bpf.c\n+++ b/net/ipv4/tcp_bpf.c\n@@ -469,6 +469,7 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,\n \tcase __SK_REDIRECT:\n \t\tredir_ingress = psock-\u003eredir_ingress;\n \t\tsk_redir = psock-\u003esk_redir;\n+\t\tsock_hold(sk_redir);\n \t\tsk_msg_apply_bytes(psock, tosend);\n \t\tif (!psock-\u003eapply_bytes) {\n \t\t\t/* Clean up before releasing the sock lock. */\n@@ -489,6 +490,7 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,\n \n \t\tif (eval == __SK_REDIRECT)\n \t\t\tsock_put(sk_redir);\n+\t\tsock_put(sk_redir);\n \n \t\tlock_sock(sk);\n \t\tsk_mem_uncharge(sk, sent);\n"
}

gemini-3.1-pro-preview

null

{
  "EnableConfigs": [
    "BPF_SYSCALL",
    "BPF_STREAM_PARSER"
  ],
  "FocusSymbols": [
    "tcp_bpf_send_verdict",
    "tcp_bpf_sendmsg",
    "tcp_bpf_sendmsg_redir"
  ],
  "Reasoning": "The patch fixes a potential use-after-free issue in `tcp_bpf_send_verdict` by holding a reference to `sk_redir` while it is being used. This is a functional change in the core BPF sockmap logic that is reachable from userspace and should be fuzzed.",
  "WorthFuzzing": true
}

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

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

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

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 1d20ba607ddf2190525103e203b51244efa4f7da
Author: syz-cluster <triage@syzkaller.com>
Date:   Sun Jul 19 16:04:50 2026 +0000

    syz-cluster: applied patch under review

diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 8e905b50deadbe..69cc8bc33bcd1c 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -469,6 +469,7 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
 	case __SK_REDIRECT:
 		redir_ingress = psock->redir_ingress;
 		sk_redir = psock->sk_redir;
+		sock_hold(sk_redir);
 		sk_msg_apply_bytes(psock, tosend);
 		if (!psock->apply_bytes) {
 			/* Clean up before releasing the sock lock. */
@@ -489,6 +490,7 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
 
 		if (eval == __SK_REDIRECT)
 			sock_put(sk_redir);
+		sock_put(sk_redir);
 
 		lock_sock(sk);
 		sk_mem_uncharge(sk, sent);

gemini-3.1-pro-preview

null

null

							input: 1948
							output: 40
							thoughts: 107
						

**Analyzing a TCP BPF Patch**

Okay, so there's a patch submitted to `net/ipv4/tcp_bpf.c`. It looks like the core of the change revolves around the `tcp_bpf_send_verdict` function. Specifically, it's adding `sock_hold(sk_redir)` and `sock_put(sk_redir)`. Immediately, I recognize this as a likely fix for a memory management issue – probably a use-after-free scenario or something similar related to that `sk_redir` socket pointer. The code comments aren't explicitly stating the issue, but these hold/put operations are red flags that are likely related to tracking usage.

Given that it's in a critical function like this, I need to thoroughly understand the context of `tcp_bpf_send_verdict`. I'll have to delve into the function's logic and trace the usage of `sk_redir` to see where the potential race or memory corruption could occur. I'll need to figure out exactly when `sk_redir` is being assigned, when it might be accessed after being freed, and how these `sock_hold` and `sock_put` calls are meant to remedy the problem. Understanding the precise call path and data flow is essential to verifying the fix's correctness and potential side effects. I'll be looking for any concurrent access scenarios and how this patch affects them.

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

{
  "Output": "net/ipv4/tcp_bpf.c=368=static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,\n--\nnet/ipv4/tcp_bpf.c-417-\nnet/ipv4/tcp_bpf.c:418:static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,\nnet/ipv4/tcp_bpf.c-419-\t\t\t\tstruct sk_msg *msg, int *copied, int flags)\n--\nnet/ipv4/tcp_bpf.c=534=static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\n--\nnet/ipv4/tcp_bpf.c-599-\nnet/ipv4/tcp_bpf.c:600:\t\terr = tcp_bpf_send_verdict(sk, psock, msg_tx, \u0026copied, flags);\nnet/ipv4/tcp_bpf.c-601-\t\tif (unlikely(err \u003c 0))\n"
}

gemini-3.1-pro-preview

null

null

							input: 2684
							output: 30
							thoughts: 45
						

Okay, here's my interpretation of that thought process, tailored for an expert audience:

**Investigating the `tcp_bpf_send_verdict` Path**

Right, so `tcp_bpf_send_verdict` is being called from within `tcp_bpf_sendmsg`. Hmm, that's interesting. I need to get a handle on the configuration options associated with this path in `tcp_bpf.c`. This isn't just a casual glance; I need to understand which features and dependencies need to be enabled at compile time to make this particular flow operational. I'm going to start by tracing the call chain, checking the config symbols involved, and making sure I have a good grasp of the control flow within `tcp_bpf.c` and its dependencies. My ultimate goal is to understand the implications of this verdict path for kernel configuration.

{
  "Expression": "tcp_bpf",
  "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: 3047
							output: 29
							thoughts: 24
						

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

**Debugging Network Configuration Dependencies**

Alright, so the first thing I've got to sort out is this `CONFIG_NET_SOCK_MSG` dependency. Seems like it's a critical piece of the puzzle. I need to figure out what functionality relies on it and if I need to enable or tweak it.

Before I commit to anything, I want to take a more holistic view. I should probably scan the broader configuration space. I'll need to check if there are *other* network configurations that this one depends on, or that depend on *it*. Perhaps there's some broader context or related settings I should be aware of before making any changes. This is standard operating procedure, really; I can't just react to one flag without understanding the bigger picture. Time to dive into the config files and see what's connected. I need to make sure I'm not breaking anything downstream or setting off any unintended consequences.

{
  "Expression": "NET_SOCK_MSG",
  "PathPrefix": "net/Kconfig"
}

{
  "Output": "net/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/Kconfig=475=config NET_SELFTESTS\n--\nnet/Kconfig-478-\nnet/Kconfig:479:config NET_SOCK_MSG\nnet/Kconfig-480-\tbool\n--\nnet/Kconfig-482-\thelp\nnet/Kconfig:483:\t  The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or\nnet/Kconfig-484-\t  ULPs (upper layer modules, e.g. TLS) to process L7 application data\n"
}

gemini-3.1-pro-preview

null

null

							input: 3523
							output: 31
							thoughts: 44
						

Here's my summary, as the thought process unfolds:

**Digging into Network Configuration**

Okay, so I'm encountering this `NET_SOCK_MSG` setting, and it seems to be intertwined with `BPF_STREAM_PARSER`. I know `NET_SOCK_MSG` is hidden which suggests it's likely a supporting configuration option. My instinct is that this relationship is driven by the `BPF_STREAM_PARSER` configuration. This sounds like it might be key to enabling some advanced BPF stream processing.

I need to see what's going on with `BPF_STREAM_PARSER`. The kernel config system is the place to start, so I'll go check the `net/Kconfig` file. That's the definitive source to see how these options are defined and related. I'm expecting to find some dependencies or defaults that explain why `NET_SOCK_MSG` gets pulled in when `BPF_STREAM_PARSER` is selected. Let's see what the Kconfig says.

{
  "Expression": "BPF_STREAM_PARSER",
  "PathPrefix": "net/Kconfig"
}

{
  "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: 3895
							output: 25
							thoughts: 44
						

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

**Investigating BPF Stream Parser Configuration**

Alright, so I need to enable `BPF_STREAM_PARSER`. That's the starting point for this feature, obviously. But hold on a second… it looks like `NET_SOCK_MSG` is also getting pulled in by `CGROUP_BPF`? I need to confirm that relationship. I want to understand *why* that dependency exists and what implications it might have for the configuration and operation of the stream parser in different cgroup contexts. I'll take a closer look at the Kconfig dependencies to clarify this. Gotta make sure I'm not missing anything critical in the setup.

{
  "Expression": "NET_SOCK_MSG",
  "PathPrefix": ""
}

{
  "Output": "include/linux/skbuff.h=886=struct sk_buff {\n--\ninclude/linux/skbuff.h-926-\t\tstruct list_head\ttcp_tsorted_anchor;\ninclude/linux/skbuff.h:927:#ifdef CONFIG_NET_SOCK_MSG\ninclude/linux/skbuff.h-928-\t\tunsigned long\t\t_sk_redir;\n--\ninclude/linux/skmsg.h=555=static inline ssize_t sk_msg_first_len(struct sock *sk)\n--\ninclude/linux/skmsg.h-572-\ninclude/linux/skmsg.h:573:#if IS_ENABLED(CONFIG_NET_SOCK_MSG)\ninclude/linux/skmsg.h-574-\n--\ninclude/linux/skmsg.h=619=static inline void skb_bpf_redirect_clear(struct sk_buff *skb)\n--\ninclude/linux/skmsg.h-622-}\ninclude/linux/skmsg.h:623:#endif /* CONFIG_NET_SOCK_MSG */\ninclude/linux/skmsg.h-624-#endif /* _LINUX_SKMSG_H */\n--\ninclude/net/tcp.h=2827=void tcp_update_ulp(struct sock *sk, struct proto *p,\n--\ninclude/net/tcp.h-2833-\ninclude/net/tcp.h:2834:#ifdef CONFIG_NET_SOCK_MSG\ninclude/net/tcp.h-2835-struct sk_msg;\n--\ninclude/net/tcp.h=2856=int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress,\ninclude/net/tcp.h-2857-\t\t\t  struct sk_msg *msg, u32 bytes, int flags);\ninclude/net/tcp.h:2858:#endif /* CONFIG_NET_SOCK_MSG */\ninclude/net/tcp.h-2859-\ninclude/net/tcp.h:2860:#if !defined(CONFIG_BPF_SYSCALL) || !defined(CONFIG_NET_SOCK_MSG)\ninclude/net/tcp.h-2861-static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)\n--\nkernel/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/Kconfig=475=config NET_SELFTESTS\n--\nnet/Kconfig-478-\nnet/Kconfig:479:config NET_SOCK_MSG\nnet/Kconfig-480-\tbool\n--\nnet/Kconfig-482-\thelp\nnet/Kconfig:483:\t  The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or\nnet/Kconfig-484-\t  ULPs (upper layer modules, e.g. TLS) to process L7 application data\n--\nnet/core/Makefile=43=obj-$(CONFIG_FAILOVER) += failover.o\nnet/core/Makefile:44:obj-$(CONFIG_NET_SOCK_MSG) += skmsg.o\nnet/core/Makefile-45-obj-$(CONFIG_BPF_SYSCALL) += sock_map.o\n--\nnet/ipv4/Kconfig=382=config INET_ESPINTCP\n--\nnet/ipv4/Kconfig-385-\tselect STREAM_PARSER\nnet/ipv4/Kconfig:386:\tselect NET_SOCK_MSG\nnet/ipv4/Kconfig-387-\tselect XFRM_ESPINTCP\n--\nnet/ipv4/Makefile=62=obj-$(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--\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: 5379
							output: 38
							thoughts: 216
						

**Analyzing the Kernel Configuration for Network Socket Message Handling**

Okay, so I'm digging into this `NET_SOCK_MSG` feature, and it looks like `BPF_SYSCALL` gets chosen when the `NET` option is enabled, which is the key here. So, `BPF_SYSCALL` alone *should* be sufficient, especially since it's definitely enabled within Syzkaller. However, I'm thinking, just to be absolutely certain and cover all bases, it might be prudent to also specify `BPF_STREAM_PARSER` and `TLS` in the configuration as well, as a kind of defensive programming. But hold on, the core element is indeed `BPF_SYSCALL` which is a more generic configuration. Therefore, as I think it through, I see I don't need to specify `BPF_SYSCALL`, but I will add `BPF_STREAM_PARSER` and `TLS` for peace of mind.

The critical change seems to be within `tcp_bpf_send_verdict`. Right, let's go and check out what exactly `tcp_bpf_send_verdict` does, and its implications here. Ah, right, it's called from `tcp_bpf_sendmsg` and, if it exists, `tcp_bpf_sendpage`. Now, let me take a look at `tcp_bpf_sendmsg` to get the whole picture.

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

{
  "Output": "net/ipv4/tcp_bpf.c=153=static int tcp_bpf_push_locked(struct sock *sk, struct sk_msg *msg,\n--\nnet/ipv4/tcp_bpf.c-163-\nnet/ipv4/tcp_bpf.c:164:int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress,\nnet/ipv4/tcp_bpf.c-165-\t\t\t  struct sk_msg *msg, u32 bytes, int flags)\n--\nnet/ipv4/tcp_bpf.c-177-}\nnet/ipv4/tcp_bpf.c:178:EXPORT_SYMBOL_GPL(tcp_bpf_sendmsg_redir);\nnet/ipv4/tcp_bpf.c-179-\n--\nnet/ipv4/tcp_bpf.c=418=static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,\n--\nnet/ipv4/tcp_bpf.c-486-\t\torigsize = msg-\u003esg.size;\nnet/ipv4/tcp_bpf.c:487:\t\tret = tcp_bpf_sendmsg_redir(sk_redir, redir_ingress,\nnet/ipv4/tcp_bpf.c-488-\t\t\t\t\t    msg, tosend, flags);\n--\nnet/ipv4/tcp_bpf.c-533-\nnet/ipv4/tcp_bpf.c:534:static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)\nnet/ipv4/tcp_bpf.c-535-{\n--\nnet/ipv4/tcp_bpf.c=640=static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS],\n--\nnet/ipv4/tcp_bpf.c-650-\tprot[TCP_BPF_TX]\t\t\t= prot[TCP_BPF_BASE];\nnet/ipv4/tcp_bpf.c:651:\tprot[TCP_BPF_TX].sendmsg\t\t= tcp_bpf_sendmsg;\nnet/ipv4/tcp_bpf.c-652-\n"
}

gemini-3.1-pro-preview

null

null

							input: 6517
							output: 40
							thoughts: 47
						

Here's my analysis of what I'm seeing:

**Analyzing `tcp_bpf_sendmsg` and its Connection to `sockmap`**

Okay, so I'm focusing on `tcp_bpf_sendmsg` right now. My immediate thought is that this function is being called within `tcp_bpf_rebuild_protos`. That's interesting, as I know that `sockmap` is often involved in these kinds of low-level network operations. My expertise tells me that this combination likely indicates some form of BPF-based packet manipulation or state management within the TCP stack, particularly concerning sockmap. I need to understand the relationship, so I'll dive into `tcp_bpf_rebuild_protos` next to see how `tcp_bpf_sendmsg` is utilized in that context and where sockmap fits in. I'm expecting to see how data is being constructed or modified before it's transmitted, potentially leveraging sockmap's capabilities for directing packets or applying custom logic.

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

{
  "Output": "net/ipv4/tcp_bpf.c=638=static struct proto tcp_bpf_prots[TCP_BPF_NUM_PROTS][TCP_BPF_NUM_CFGS];\nnet/ipv4/tcp_bpf.c-639-\nnet/ipv4/tcp_bpf.c:640:static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS],\nnet/ipv4/tcp_bpf.c-641-\t\t\t\t   struct proto *base)\n--\nnet/ipv4/tcp_bpf.c=660=static void tcp_bpf_check_v6_needs_rebuild(struct proto *ops)\n--\nnet/ipv4/tcp_bpf.c-664-\t\tif (likely(ops != tcpv6_prot_saved)) {\nnet/ipv4/tcp_bpf.c:665:\t\t\ttcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV6], ops);\nnet/ipv4/tcp_bpf.c-666-\t\t\tsmp_store_release(\u0026tcpv6_prot_saved, ops);\n--\nnet/ipv4/tcp_bpf.c=672=static int __init tcp_bpf_v4_build_proto(void)\nnet/ipv4/tcp_bpf.c-673-{\nnet/ipv4/tcp_bpf.c:674:\ttcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV4], \u0026tcp_prot);\nnet/ipv4/tcp_bpf.c-675-\treturn 0;\n"
}

gemini-3.1-pro-preview

null

null

							input: 7247
							output: 147
							thoughts: 560
						

**Analyzing a BPF Sockmap Patch for TCP Sockets**

Okay, so this patch is aimed at fixing a bug related to `sendmsg` handling for TCP sockets that are part of a sockmap. The core of the logic is in `tcp_bpf_send_verdict`, which is the function that deals with the verdict returned by a BPF program attached to the sockmap. The key change here is the addition of `sock_hold(sk_redir)` and `sock_put(sk_redir)` calls around `sk_msg_apply_bytes` and `tcp_bpf_sendmsg_redir`.  This suggests some reference counting or lifetime management issue that's being addressed. This is a clear functional fix, not just a performance tweak.

My immediate next step is to fuzz this.  Given the potential for subtle race conditions or memory corruption bugs in socket-level code, fuzzing is essential to validate the fix's correctness and robustness.

Let's quickly review the relevant symbols: `tcp_bpf_send_verdict`, `tcp_bpf_sendmsg`, and `tcp_bpf_sendmsg_redir` – those are the key functions to keep in mind.

Now, let's look at the kernel configs. We need to make sure the right features are enabled for the patch to be relevant. The original notes mention `BPF_SYSCALL`, `NET_SOCK_MSG`, and `BPF_STREAM_PARSER`. Wait a minute, `NET_SOCK_MSG` is a hidden config; that simplifies things.  I can just enable `BPF_SYSCALL` and `BPF_STREAM_PARSER`.  Let's double check that... Yep, `BPF_SYSCALL` automatically brings in `NET_SOCK_MSG` as long as `NET` is enabled, and we're definitely in the networking code. So, `BPF_SYSCALL` is the main one; `BPF_STREAM_PARSER` might provide additional coverage, but `BPF_SYSCALL` is the crucial one to focus on.

Okay, time for a more thorough code review of the patch. Let's make sure I'm not missing anything.  The `sock_hold` and `sock_put` additions are definitely there, surrounding the core logic. Double check the context... yes, that looks right. It's definitely a functional change, not just a cosmetic one.  This strengthens my conviction that it should be fuzzed.

Right, I'm ready to call `set-results`.

{
  "EnableConfigs": [
    "BPF_SYSCALL",
    "BPF_STREAM_PARSER"
  ],
  "FocusSymbols": [
    "tcp_bpf_send_verdict",
    "tcp_bpf_sendmsg",
    "tcp_bpf_sendmsg_redir"
  ],
  "Reasoning": "The patch fixes a potential use-after-free issue in `tcp_bpf_send_verdict` by holding a reference to `sk_redir` while it is being used. This is a functional change in the core BPF sockmap logic that is reachable from userspace and should be fuzzed.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "BPF_SYSCALL",
    "BPF_STREAM_PARSER"
  ],
  "FocusSymbols": [
    "tcp_bpf_send_verdict",
    "tcp_bpf_sendmsg",
    "tcp_bpf_sendmsg_redir"
  ],
  "Reasoning": "The patch fixes a potential use-after-free issue in `tcp_bpf_send_verdict` by holding a reference to `sk_redir` while it is being used. This is a functional change in the core BPF sockmap logic that is reachable from userspace and should be fuzzed.",
  "WorthFuzzing": true
}