SB2026050964 - Always-Incorrect Control Flow Implementation in Linux kernel x86 mm

Description

This security bulletin contains information about 1 vulnerability.

1) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-43331)

CWE-ID: CWE-670 - Always-Incorrect Control Flow Implementation

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 handling of kcOV instrumentation state in machine kexec code when executing kexec on a KCOV-instrumented kernel. A local user can trigger a kexec operation to cause a denial of service.

Exploitation requires CONFIG_KEXEC and CONFIG_KCOV to be enabled simultaneously, and the issue is not relevant to 32-bit kernels.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/1e3e98596c2769721ade0418434852fb3af4849a
• https://git.kernel.org/stable/c/917e3ad3321e75ca0223d5ccf26ceda116aa51e1
• https://git.kernel.org/stable/c/de05c66fab8847237a9ca216934e56d3ee837f08