High 7.8Published Sep 11, 2026

CVE-2026-89755mm/migrate_device: clear stale mapping after freeing swapcache

Updated under an hour ago (2026-10-19 08:00 UTC)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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. Reset nr to 1 so each split folio is processed separately, including its own swapcache removal and mapping lookup. Refresh the saved mapping after folio_free_swap() so the current folio state is used during migration.

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Received
Record last updated: Sep 21, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from df263d9a7dffee94ca5391120ee3b0587efa07f1 before 4fa91f7bbc4135240b67daac03fc17d9e180a331; from df263d9a7dffee94ca5391120ee3b0587efa07f1 before 8ffedc6573a665cdc31ebe47eae7b32b78d0df83; from df263d9a7dffee94ca5391120ee3b0587efa07f1 before 34a00895d032a414830d41106a09329ae6c251b6	CNA record

References

https://git.kernel.org/stable/c/4fa91f7bbc4135240b67daac03fc17d9e180a331
https://git.kernel.org/stable/c/8ffedc6573a665cdc31ebe47eae7b32b78d0df83
https://git.kernel.org/stable/c/34a00895d032a414830d41106a09329ae6c251b6

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.