SB20260507103 - Improper Check or Handling of Exceptional Conditions in Linux kernel kcm

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Check or Handling of Exceptional Conditions (CVE-ID: CVE-2026-43244)

CWE-ID: CWE-703 - Improper Check or Handling of Exceptional Conditions

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper cleanup of an empty skb in the kcm_sendmsg()/kcm_write_msgs() message handling path when processing a partial sendmsg error followed by message completion. A local user can trigger a copy failure after a new frag_list skb is linked and then complete the message with a zero-length write to cause a kernel warning.

The issue occurs for SOCK_SEQPACKET sockets when partial data has already been copied and the message is later completed.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/7af58f76e4b404a74c836881a845e6652db8a09f
• https://git.kernel.org/stable/c/9ea3671d70ee07480d80bebe86696397c4e99fb7
• https://git.kernel.org/stable/c/b1e3edf688a88c1a3ac41657055d9c136a08cd25
• https://git.kernel.org/stable/c/ca220141fa8ebae09765a242076b2b77338106b0