{"id":"CVE-2026-98999","revision":"bc7e30716290450fa30fe83790eacc79","records":[{"revision":"bc7e30716290450fa30fe83790eacc79","observedAt":"2026-10-23T16:01:20.601+00:00","statement":{"source":"cve-program","id":"CVE-2026-98999","aliases":[],"title":"drm/xe: Fix stale pinned_link entry when fb-pin performs the final unpin","description":"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)","state":0,"publishedAt":"2026-10-23T12:20:19.451+00:00","modifiedAt":"2026-10-23T12:20:19.451+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/gpu/drm/xe/xe_bo.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"44e694958b95395bd1c41508c88c8ca141bf9bd7\",\n                            \"lessThan\": \"3a11adcfd9a2de74d405bd3e8c4d7a1b328e4684\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"44e694958b95395bd1c41508c88c8ca141bf9bd7\",\n                            \"lessThan\": \"b3eaff982839e5c22912d604cd8e7748cece8d63\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"44e694958b95395bd1c41508c88c8ca141bf9bd7\",\n                            \"lessThan\": \"cf238c067eaae1cbfb00738e29219b9568d2313e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/gpu/drm/xe/xe_bo.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.8\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.8\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.57\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.11\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/3a11adcfd9a2de74d405bd3e8c4d7a1b328e4684","https://git.kernel.org/stable/c/b3eaff982839e5c22912d604cd8e7748cece8d63","https://git.kernel.org/stable/c/cf238c067eaae1cbfb00738e29219b9568d2313e"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98999","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98999","identifiers":["CVE-2026-98999"]},"retained":false,"historicalAffected":[]}],"coverage":[]}