SB20260508138 - Improper locking in Linux kernel mm

Description

This security bulletin contains information about 1 vulnerability.

1) Improper locking (CVE-ID: CVE-2026-43404)

CWE-ID: CWE-667 - Improper Locking

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/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 lock handling in hmm_range_fault() and do_swap_page() when handling device-private folio migration to system memory. A local user can trigger page fault handling that spins on a folio lock to cause a denial of service.

Exploitation requires a specific memory migration scenario involving device-private folios, deferred migration PTE insertion, and no or voluntary-only preemption.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/7e6e2fc91d4b9b12ec6e137019532568ebcf2680
• https://git.kernel.org/stable/c/94b6d0ba4b640ba23bb6c708a59316e74e5ede63
• https://git.kernel.org/stable/c/b570f37a2ce480be26c665345c5514686a8a0274