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.
Published: 2026-09-03
Score: n/a
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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History

Thu, 03 Sep 2026 13:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-704

Thu, 03 Sep 2026 07:30:00 +0000

Type Values Removed Values Added
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.
Title bpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-03T08:21:53.143Z

Reserved: 2026-08-26T14:34:25.789Z

Link: CVE-2026-80738

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-03T13:06:12.910

Modified: 2026-09-03T13:06:12.910

Link: CVE-2026-80738

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-03T13:15:04Z

Weaknesses
  • CWE-704

    Incorrect Type Conversion or Cast