SB2026050863 - Improper update of reference count in Linux kernel mlx5 core driver

Description

This security bulletin contains information about 1 vulnerability.

1) Improper update of reference count (CVE-ID: CVE-2026-43465)

CWE-ID: CWE-911 - Improper Update of Reference Count

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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 reference counting in the mlx5 XDP receive path when processing XDP multi-buffer packets on striding RQ. A local user can trigger XDP actions that alter the XDP buffer layout to cause a kernel warning and crash.

The issue affects multiple XDP actions, including XDP_TX, XDP_REDIRECT, XDP_PASS, and packet drops after buffer layout changes caused by bpf_xdp_pull_data() or bpf_xdp_adjust_tail().

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/043bd62f748bc9fd98154037aa598cffbd3c667c
• https://git.kernel.org/stable/c/7d7342a18fadcdb70a63b3c930dc63528ce51832
• https://git.kernel.org/stable/c/db25c42c2e1f9c0d136420fff5e5700f7e771a6f