PT-2025-14365 · Linux+5 · Linux Kernel+5
Published
2025-03-06
·
Updated
2026-04-20
·
CVE-2025-21984
CVSS v3.1
4.7
Medium
| Vector | AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel versions prior to the fixed version
Description
A vulnerability in the Linux kernel has been resolved, related to the userfaultfd move function encountering swapcache. The issue arises when the function checks if the PTE entry is present or a swap entry and handles it incorrectly, creating a race window. This can lead to critical issues, including a kernel BUG, depending on the system configuration. If KSM is disabled, both small and large folios can trigger a BUG during the add rmap operation.
Recommendations
To resolve the issue, update to a version of the Linux kernel that includes the fix for the userfaultfd move function. As a temporary workaround, consider disabling the userfaultfd feature until a patch is available. Restrict access to the swapcache to minimize the risk of exploitation. Avoid using the
folio variable in the affected API endpoints until the issue is resolved.Note: The provided information does not specify the exact fixed version of the Linux kernel. Therefore, it is recommended to update to the latest available version to ensure the vulnerability is resolved.
Exploit
Fix
Race Condition
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Weakness Enumeration
Related Identifiers
Affected Products
Alt Linux
Astra Linux
Linuxmint
Linux Kernel
Red Os
Ubuntu