0.0
NA
CVE-2026-80738
bpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie
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.

INFO

Published Date :

Sept. 3, 2026, 8:21 a.m.

Last Modified :

Sept. 3, 2026, 8:21 a.m.

Remotely Exploit :

No

Source :

Linux
Affected Products

The following products are affected by CVE-2026-80738 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
Solution
Update the Linux kernel to fix socket state validation in BPF TCP functions.
  • Apply the Linux kernel patch for BPF TCP syncookie.
  • Ensure sk->sk_state is checked before sk->sk_protocol.
  • Validate 'sk' represents a full socket before access.

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