{"api_version":"1","generated_at":"2026-09-15T03:41:33+00:00","cve":"CVE-2026-89755","urls":{"html":"https://cve.report/CVE-2026-89755","api":"https://cve.report/api/cve/CVE-2026-89755.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89755","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89755"},"summary":{"title":"mm/migrate_device: clear stale mapping after freeing swapcache","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:20:06","updated_at":"2026-09-13 07:17:39"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"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"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/8ffedc6573a665cdc31ebe47eae7b32b78d0df83","name":"https://git.kernel.org/stable/c/8ffedc6573a665cdc31ebe47eae7b32b78d0df83","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/34a00895d032a414830d41106a09329ae6c251b6","name":"https://git.kernel.org/stable/c/34a00895d032a414830d41106a09329ae6c251b6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89755","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89755","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected df263d9a7dffee94ca5391120ee3b0587efa07f1 8ffedc6573a665cdc31ebe47eae7b32b78d0df83 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected df263d9a7dffee94ca5391120ee3b0587efa07f1 34a00895d032a414830d41106a09329ae6c251b6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.6","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"89755","cve":"CVE-2026-89755","epss":"0.001430000","percentile":"0.039670000","score_date":"2026-09-14","updated_at":"2026-09-15 00:00:42"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["mm/migrate_device.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"8ffedc6573a665cdc31ebe47eae7b32b78d0df83","status":"affected","version":"df263d9a7dffee94ca5391120ee3b0587efa07f1","versionType":"git"},{"lessThan":"34a00895d032a414830d41106a09329ae6c251b6","status":"affected","version":"df263d9a7dffee94ca5391120ee3b0587efa07f1","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["mm/migrate_device.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.6"},{"lessThan":"6.6","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"6.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.6","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The bug is in __migrate_device_pages() on the migrate-to-device path (migrate_vma_pages), reached from local GPU HMM/SVM ioctls such as AMDKFD_IOC_SVM, DRM_NOUVEAU_SVM_BIND (DRM_RENDER_ALLOW), and Intel Xe drm_pagemap_migrate_to_devmem, not from network packets.\nAC:L - The attacker controls both preconditions: anonymous pages in their VMA, optionally kept in swapcache via pageout/swapin, then a migrate-to-VRAM ioctl. folio_free_swap() succeeds on locked mapped swapcache folios with swap count 0, which the attacker can arrange; no victim timing or uncontrollable layout is required.\nPR:L - Nouveau SVM bind is DRM_RENDER_ALLOW and KFD SVM/Xe pagemap paths have no capable() or DRM-master check. An unprivileged local user with typical render/video-group access to /dev/dri/renderD* or /dev/kfd on GPU systems can trigger the migration.\nUI:N - The attacker drives the whole sequence in their own process (anonymous mmap, optional madvise pageout, and GPU SVM migrate-to-device ioctls). No action by another user or administrator is required.\nS:U - Impact is host-kernel swap-cache and folio-refcount corruption, i.e. standard local privilege escalation in the same security authority, not a KVM/Xen guest-to-host escape or IOMMU/DMA boundary bypass.\nC:H - After folio_free_swap() the stale mapping still points at swap_space, so folio_migrate_mapping() xas_store()s a device-private folio into the global swap cache and underflows the source refcount; that UAF/type confusion of swap_space.i_pages yields an arbitrary kernel read primitive.\nI:H - The same xarray insertion and refcount underflow corrupt shared MM metadata (swap cache and folio references), which is exploitable for heap reuse and arbitrary kernel writes or control-flow hijack, not a bounded integrity change.\nA:H - Invalid reference accounting on swap_space.i_pages is documented to hit a folio reference-count BUG, and the resulting underflow/UAF also causes kernel oops or panic even without a completed exploit."}]}],"providerMetadata":{"dateUpdated":"2026-09-13T06:34:01.430Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/8ffedc6573a665cdc31ebe47eae7b32b78d0df83"},{"url":"https://git.kernel.org/stable/c/34a00895d032a414830d41106a09329ae6c251b6"}],"title":"mm/migrate_device: clear stale mapping after freeing swapcache","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89755","datePublished":"2026-09-11T19:46:58.295Z","dateReserved":"2026-09-11T19:38:34.763Z","dateUpdated":"2026-09-13T06:34:01.430Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:20:06","lastModifiedDate":"2026-09-13 07:17:39","problem_types":[],"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}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89755","Ordinal":"1","Title":"mm/migrate_device: clear stale mapping after freeing swapcache","CVE":"CVE-2026-89755","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89755","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"mm/migrate_device: clear stale mapping after freeing swapcache"}]}}}