{"schema":"threatline.record/2","record":{"id":"CVE-2026-98999","aliases":[],"summary":"drm/xe: Fix stale pinned_link entry when fb-pin performs the final unpin","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe: Fix stale pinned_link entry when fb-pin performs the final unpin\n\nxe_bo_pin_external() and xe_bo_unpin_external() maintain the bo's\npinned_link list membership in xe->pinned.late.external, based on\nwhether the current call is the outermost pin or the final unpin.\nHowever, the same external bo's pin_count can also be raised and\nlowered directly by __xe_pin_fb_vma()/__xe_unpin_fb_vma(), which pin\nthe bo as a display scanout buffer without going through\nxe_bo_pin_external()/xe_bo_unpin_external() at all, and have no\nnotion of, or ownership over, pinned_link.\n\nIf a bo is pinned both externally (e.g. dma-buf export) and as an fb,\nand the external unpin happens first, xe_bo_unpin_external() correctly\nobserves pin_count > 1 and leaves the bo on pinned_link. When the fb\nunpin later performs the true last unpin (pin_count 1 -> 0), it never\ntouches pinned_link, leaving the bo linked on xe->pinned.late.external\nindefinitely. Once the bo is subsequently freed, this stale list entry\npoints into freed memory, corrupting the list and risking a\nuse-after-free the next time the list is walked or spliced.\n\nThe backup object pin/unpin sites in xe_bo_notifier_prepare_pinned()/\nxe_bo_notifier_unprepare_pinned() have the same bypass characteristic,\nthough they never add their bo to a pinned list, so are not affected\nby this particular list-corruption issue.\n\nMove the pinned_link removal into xe_bo_account_unpin(), which already\nruns on every unpin path (kernel, external, framebuffer, backup\nobject) right before the true 1 -> 0 pin_count transition. Since\nlist_del_init() only operates on the node itself, this removal is\nlist-agnostic and safe to perform regardless of which list (external\nor kernel_bo_present) the bo happens to be linked on, or which code\npath is performing the final unpin. Drop the now-redundant explicit\nlist_del_init() calls in xe_bo_unpin_external() and xe_bo_unpin().\n\nv2:\n- New patch\n\nv3:\n- Rebased on changes to previous patch.\n\n(cherry picked from commit ca58d36a1f93af586ee93b340c9f9fd81312cc01)","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98999","source_modified_at":"2026-10-24T14:09:56.167Z","fetched_at":"2026-10-24T14:26:37.433577Z","product":"Linux","vendor":"Linux","versions":[{"version":"44e694958b95395bd1c41508c88c8ca141bf9bd7","lessThan":"3a11adcfd9a2de74d405bd3e8c4d7a1b328e4684","status":"affected","versionType":"git"},{"version":"44e694958b95395bd1c41508c88c8ca141bf9bd7","lessThan":"b3eaff982839e5c22912d604cd8e7748cece8d63","status":"affected","versionType":"git"},{"version":"44e694958b95395bd1c41508c88c8ca141bf9bd7","lessThan":"cf238c067eaae1cbfb00738e29219b9568d2313e","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98999","source_modified_at":"2026-10-24T14:09:56.167Z","fetched_at":"2026-10-24T14:26:37.433577Z","product":"Linux","vendor":"Linux","versions":[{"version":"6.8","status":"affected"},{"version":"0","lessThan":"6.8","status":"unaffected","versionType":"semver"},{"version":"6.18.57","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.11","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98999","source_modified_at":"2026-10-24T14:09:56.167Z","fetched_at":"2026-10-24T14:26:37.433577Z","package":{"name":"Linux","ecosystem":null},"version":"3a11adcfd9a2de74d405bd3e8c4d7a1b328e4684","basis":"first unaffected version stated in the CVE record"}],"cvss":7.8,"severity":"High","kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-23T12:20:19.451Z","modified_at":"2026-10-24T14:09:56.167Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98999","fetched_at":"2026-10-24T14:26:37.433577Z","source_modified_at":"2026-10-24T14:09:56.167Z"}],"sources":["CVE List"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/3a11adcfd9a2de74d405bd3e8c4d7a1b328e4684"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/b3eaff982839e5c22912d604cd8e7748cece8d63"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/cf238c067eaae1cbfb00738e29219b9568d2313e"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-24T14:09:56.167Z","content_hash":"ec3d53af298db2060d56ec0bb7b7b2faaaffd622a8b113b0c8c9a6bcd047b664"}}