CVE-2026-46017: In the Linux kernel, the following vulnerability has been resolved: mm: fix deferred split queue races during migration migrate_folio_move() records the…

high7

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]

Affected

4 ranges

Vendor	Product	Version range	Fixed in
linux	linux	< 7.0.4	7.0.4
linux	linux	>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < cbf75cf212ee6e499abc1757fb4b5ae6d70ed0aa	cbf75cf212ee6e499abc1757fb4b5ae6d70ed0aa
linux	linux	>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 3bac01168982ec3e3bf87efdc1807c7933590a85	3bac01168982ec3e3bf87efdc1807c7933590a85
linux	linux_kernel	—	—