CVE-2026-46017 mm: fix deferred split queue races during migration
A race condition in the Linux kernel memory management subsystem can cause a kernel warning and potential denial of service during page migration.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-46017?
CVE-2026-46017 is a medium-severity vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
mm: fix deferred split queue races during migration
migrate_folio_move() records the deferred split queue state from src and replays it on dst. Replaying it after remove_migration_ptes(src, dst, 0) makes dst visible before it is requeued, so a concurrent rmap-removal path can mark dst partially mapped and trip the WARN in deferred_split_folio().
Move the requeue before remove_migration_ptes() so dst is back on the deferred split queue before it becomes visible again.
Because migration still holds dst locked at that point, teach deferred_split_scan() to requeue a folio when folio_trylock() fails. Otherwise a fully mapped underused folio can be dequeued by the shrinker and silently lost from split_queue.
[[email protected]: move the comment]
Weakness: CWE-362
Which versions are affected by CVE-2026-46017?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46017?
Apply the vendor's patch.
Is CVE-2026-46017 being exploited?
There is no known exploitation of CVE-2026-46017 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88425, BELL-CVE-2026-46017, DEBIAN-CVE-2026-46017, GHSA-88w3-x23r-c432, ROOT-OS-DEBIAN-11-CVE-2026-46017, ROOT-OS-DEBIAN-12-CVE-2026-46017 and 2 more.