CVE-2026-89755 - mm/migrate_device: clear stale mapping after freeing swapcache
Brief
CVE ID : CVE-2026-89755
Published : Sept. 11, 2026, 8:20 p. m.
- 32 minutes ago
Description : In the Linux kernel, the following vulnerability has been resolved:
mm/migrate_device: clear stale mapping after freeing swapcache
__migrate_device_pages() reads the folio mapping before calling folio_free_swap(). When folio_free_swap() succeeds, the folio is removed from the swap cache, but the saved mapping still points to swap_space.
Passing the stale mapping to folio_migrate_mapping() makes it use the mapped-folio path for a folio that is no longer in swapcache. It can then operate on swap_space. i_pages with invalid reference accounting, eventually triggering a folio reference count BUG.
After a successful split, nr still contains the number of pages in the original large folio, although each resulting page is now a separate order-0 folio.