CVE-2026-89755: mm/migrate_device: clear stale mapping after freeing swapcache
Vulnerability summary
CVE-2026-89755 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 4.8% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 6 · Related 6Timeline
- 11-09-2026PublishedVulnerability first disclosed.
- 21-10-2026Last modifiedVulnerability information updated.
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. 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 metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.16%
Chance of exploitation in the next 30 days
Percentile
5%
Versus all other CVEs
30-day change
Decrease -0.02 pp
From 0.17% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu142 products
- linuxAll versions (No fix recorded)
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian2 products
- linux< 6.12.111-1 | < 7.2.6-1
- linux-6.12< 6.12.111-1~deb12u1
Linux1 product
- linux≥ df263d9a7dffee94ca5391120ee3b0587efa07f1, < 92db780dd644590c751246187e1229d5ac2e5544 | ≥ df263d9a7dffee94ca5391120ee3b0587efa07f1, < 4fa91f7bbc4135240b67daac03fc17d9e180a331 | ≥ df263d9a7dffee94ca5391120ee3b0587efa07f1, < 8ffedc6573a665cdc31ebe47eae7b32b78d0df83 | ≥ df263d9a7dffee94ca5391120ee3b0587efa07f1, < 34a00895d032a414830d41106a09329ae6c251b6 | 6.6
3 vendors · 145 products