Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie bpf_tcp_gen_syncookie and bpf_tcp_check_syncookie accept a socket pointer 'sk' with argument type ARG_PTR_TO_BTF_ID_SOCK_COMMON. However, they access sk->sk_protocol without validating whether 'sk' represents a full socket. Fix this issue by checking sk->sk_state != TCP_LISTEN before inspecting sk->sk_protocol in both bpf_tcp_gen_syncookie and bpf_tcp_check_syncookie. Since mini-sockets are never in the TCP_LISTEN state, the condition short-circuits and prevents dereferencing fullsock-specific fields.
References6
- git.kernel.org/stable/c/22c2169770ad3b3595690e51caac875178cf496d
- git.kernel.org/stable/c/23f682083aa3fbc0c49667818efd6979a8bc5ac2
- git.kernel.org/stable/c/31a420a822ff92e2090bd5d65efe8e34e2d6d9b8
- git.kernel.org/stable/c/5702e4c259809c760912c477c4ae34e9217bb4d9
- git.kernel.org/stable/c/b5525e853a2a08a9559adb84b0616025958dc542
- git.kernel.org/stable/c/b75f1c071f31be7f4b950721e04240c250091ad4
Metrics
- CVSS 3.1
-
7.3
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L - EPSS — exploit probability
- 0% percentile: 7 · as of 3 November 2026
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