SB20260425134 - Race condition in Linux kernel mm

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-31575)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 6.8 [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]

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

The vulnerability exists due to a race condition in mfill_atomic_hugetlb() when handling userfaultfd hugetlb faults. A local user can trigger faults on different addresses within the same huge page to cause a denial of service.

The issue can corrupt the reservation map and trigger the BUG_ON in resv_map_release().

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/08282b1bf74c69fc8ecd25493e7fdb5460f01290
• https://git.kernel.org/stable/c/574501ede47ac439afd67ba9812bc66722d500ba
• https://git.kernel.org/stable/c/f4689fc089765d36c026063fb22d23533e883eb6