CVE-2026-89755
Full vulnerability record from the local CVENow database.
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.
View original CVE JSON
{
"id": "CVE-2026-89755",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-11T20:20:06.533",
"lastModified": "2026-10-21T13:20:24.467",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/migrate_device: clear stale mapping after freeing swapcache\n\n__migrate_device_pages() reads the folio mapping before calling\nfolio_free_swap(). When folio_free_swap() succeeds, the folio is removed\nfrom the swap cache, but the saved mapping still points to swap_space.\n\nPassing the stale mapping to folio_migrate_mapping() makes it use the\nmapped-folio path for a folio that is no longer in swapcache. It can then\noperate on swap_space.i_pages with invalid reference accounting,\neventually triggering a folio reference count BUG.\n\nAfter a successful split, nr still contains the number of pages in the\noriginal large folio, although each resulting page is now a separate\norder-0 folio. Reset nr to 1 so each split folio is processed separately,\nincluding its own swapcache removal and mapping lookup.\n\nRefresh the saved mapping after folio_free_swap() so the current folio\nstate is used during migration."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"mm/migrate_device.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "df263d9a7dffee94ca5391120ee3b0587efa07f1",
"lessThan": "92db780dd644590c751246187e1229d5ac2e5544",
"versionType": "git",
"status": "affected"
},
{
"version": "df263d9a7dffee94ca5391120ee3b0587efa07f1",
"lessThan": "4fa91f7bbc4135240b67daac03fc17d9e180a331",
"versionType": "git",
"status": "affected"
},
{
"version": "df263d9a7dffee94ca5391120ee3b0587efa07f1",
"lessThan": "8ffedc6573a665cdc31ebe47eae7b32b78d0df83",
"versionType": "git",
"status": "affected"
},
{
"version": "df263d9a7dffee94ca5391120ee3b0587efa07f1",
"lessThan": "34a00895d032a414830d41106a09329ae6c251b6",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"mm/migrate_device.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.6",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.6",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.111",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.4",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/34a00895d032a414830d41106a09329ae6c251b6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4fa91f7bbc4135240b67daac03fc17d9e180a331",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8ffedc6573a665cdc31ebe47eae7b32b78d0df83",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/92db780dd644590c751246187e1229d5ac2e5544",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}