CVE-2026-31589

Description

In the Linux kernel, the following vulnerability has been resolved: mm: call ->free_folio() directly in folio_unmap_invalidate() We can only call filemap_free_folio() if we have a reference to (or hold a lock on) the mapping. Otherwise, we've already removed the folio from the mapping so it no longer pins the mapping and the mapping can be removed, causing a use-after-free when accessing mapping->a_ops. Follow the same pattern as __remove_mapping() and load the free_folio function pointer before dropping the lock on the mapping. That lets us make filemap_free_folio() static as this was the only caller outside filemap.c.

Predictions

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

References

• https://git.kernel.org/stable/c/615d9bb2ccad42f9e21d837431e401db2e471195
• https://git.kernel.org/stable/c/b667df39d98a7a24be7c2a40ff0863dac1ad2cd7
• https://git.kernel.org/stable/c/c330e65ea59c4805d6ab6757c4ddfe8c63acef31
• https://git.kernel.org/stable/c/efc52947247a21bbf79059539bbbd40f4ea76f00
• https://www.suse.com/security/cve/CVE-2026-31589.html
• https://security-tracker.debian.org/tracker/CVE-2026-31589

CWEs

CWE-416