CVE-2025-21931

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to the version containing commit b15c87263a69

Description A vulnerability in the Linux kernel has been resolved, related to the handling of hwpoisoned pages. The issue arises when the folio lock is not held before calling try to unmap for a hwpoisoned page, leading to a potential kernel bug. This problem was introduced by a commit that added page poison checks to make offline hwpoisoned pages possible. The vulnerability can cause a warning to be produced if the folio is not locked during unmap, resulting in a kernel BUG.

Recommendations For Linux kernel versions prior to the version containing commit b15c87263a69, apply the patch that includes the commit to fix the issue. As a temporary workaround, consider adding the necessary folio lock before calling try to unmap for hwpoisoned pages to prevent the kernel bug.