SB20260509102 - Improper locking in Linux kernel mm

Description

This security bulletin contains information about 1 vulnerability.

1) Improper locking (CVE-ID: CVE-2026-43285)

CWE-ID: CWE-667 - Improper Locking

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 attacker to cause a denial of service.

The vulnerability exists due to improper locking in mm/slab get_from_any_partial() when handling an NMI context allocation path. A local attacker can trigger an NMI-context slab allocation to cause a denial of service.

The issue arises because current->mems_allowed_seq is accessed through a seqcount_spinlock_t that is not NMI-safe, which can lead to an unsafe locking scenario and deadlock.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/144080a5823b2dbd635acb6decf7ab23182664f3
• https://git.kernel.org/stable/c/353dd9934447b9193643ae1afd938607a74d4915
• https://git.kernel.org/stable/c/efd767ddcef0669bbd33c6a823ea0a88f06d4b29