SB20260812379 - Always-Incorrect Control Flow Implementation in Linux kernel mm

Description

This security bulletin contains information about 1 vulnerability.

1) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-68163)

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

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 memory corruption.

The vulnerability exists due to improper handling of device-private PMD entries in page_vma_mapped_walk() in mm/page_vma_mapped.c when processing device-private PMD entries during page mapping walks with migration handling. A local user can trigger page_vma_mapped_walk() to misinterpret a device-private entry as a migration entry to cause memory corruption.

A race condition may also occur if a device-private PMD is split before the PMD lock is acquired.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/ab6209f4b48a98ef14d6766acdb62aa9bb32e670
• https://git.kernel.org/stable/c/f84ca9b1888d8fce7dfefe0e750fa971f8797486