{"api_version":"1","generated_at":"2026-10-08T12:05:09+00:00","cve":"CVE-2026-98166","urls":{"html":"https://cve.report/CVE-2026-98166","api":"https://cve.report/api/cve/CVE-2026-98166.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98166","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98166"},"summary":{"title":"drm/ttm: fix swapped-out resources never leaving their bulk_move range","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/ttm: fix swapped-out resources never leaving their bulk_move range\n\nttm_tt_swapout() returns the number of pages swapped out on success and\na negative error code on failure; for a populated ttm it never returns\nzero. Commit b2ed01e7ad3d (\"drm/ttm: Fix ttm_bo_swapout() infinite LRU\nwalk on swapout failure\") moved the bulk_move bookkeeping in\nttm_bo_swapout_cb() under \"if (!ret)\", so the\nttm_resource_del_bulk_move_unevictable() / ttm_resource_move_to_lru_tail()\npair is now skipped on every successful swapout. The equivalent change\nfor the shrinker in commit 1d59f36e95f7 (\"drm/ttm: Fix ttm_bo_shrink()\ninfinite LRU walk on backup failure\") tests \"lret > 0\", which is what\nwas intended here as well.\n\nBefore b2ed01e7ad3d the resource was taken off the bulk_move before the\nswapout; since then a swapped-out resource stays inside its BO's\nbulk_move range (and on the manager LRU) although it is unevictable.\nWhen it is later freed or the BO leaves the bulk_move\n(ttm_resource_free(), ttm_bo_set_bulk_move() via amdgpu_vm_bo_del()),\nttm_resource_del_bulk_move() skips it because of its\n!ttm_resource_unevictable() guard, so a range endpoint in pos->first /\npos->last is left pointing at freed memory. The next\nttm_lru_bulk_move_tail() or ttm_resource_add_bulk_move() on that cursor\nis a use-after-free, seen as the resv WARN in ttm_lru_bulk_move_add(),\n\"list_del corruption\" in ttm_resource_move_to_lru_tail() or a NULL\ndereference in ttm_resource_manager_next() -- minutes to hours after a\nhibernation, or at process exit / reboot following one. Samuel\nAinsworth's analysis of drm/amd issue 5387 (see Link) identified the\ndangling cursor; the missing removal at swapout time is the reason it\ndangles.\n\nTesting the condition for success restores the removal. On an AMD\nPhoenix APU (ASUS UM3406GA, gfx1103) running suspend-then-hibernate on\na 7.0.y stable kernel carrying the backport (Ubuntu 7.0.0-31) the bug\ncrashed 5 of 18 hibernation cycles; a function profile of one\nhibernation showed 336 ttm_tt_swapout() calls and zero\nttm_resource_del_bulk_move_unevictable() calls. With this change the\nremoval happens for every swapped-out resource and 12 further cycles\nwere clean.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-06 09:17:58","updated_at":"2026-10-07 07:17:03"},"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/1169fe8c11ca45e3f91d59a73eb271d0ca8a7fb0","name":"https://git.kernel.org/stable/c/1169fe8c11ca45e3f91d59a73eb271d0ca8a7fb0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3db7d7d583419f7b1f2e141e36418802dbb25cf8","name":"https://git.kernel.org/stable/c/3db7d7d583419f7b1f2e141e36418802dbb25cf8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98166","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98166","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b2ed01e7ad3de80333e9b962a44024b094bc0b2b 1169fe8c11ca45e3f91d59a73eb271d0ca8a7fb0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b2ed01e7ad3de80333e9b962a44024b094bc0b2b 3db7d7d583419f7b1f2e141e36418802dbb25cf8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0124a09e3e5f5f6080efe9663b27af27933f8382 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.0.10 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.8 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc4 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"98166","cve":"CVE-2026-98166","epss":"0.001980000","percentile":"0.086840000","score_date":"2026-10-06","updated_at":"2026-10-07 00:14:55"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/gpu/drm/ttm/ttm_bo.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"1169fe8c11ca45e3f91d59a73eb271d0ca8a7fb0","status":"affected","version":"b2ed01e7ad3de80333e9b962a44024b094bc0b2b","versionType":"git"},{"lessThan":"3db7d7d583419f7b1f2e141e36418802dbb25cf8","status":"affected","version":"b2ed01e7ad3de80333e9b962a44024b094bc0b2b","versionType":"git"},{"status":"affected","version":"0124a09e3e5f5f6080efe9663b27af27933f8382","versionType":"git"},{"lessThan":"7.1","status":"affected","version":"7.0.10","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/gpu/drm/ttm/ttm_bo.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.1"},{"lessThan":"7.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.8","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc4","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.8","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc4","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0.10","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/ttm: fix swapped-out resources never leaving their bulk_move range\n\nttm_tt_swapout() returns the number of pages swapped out on success and\na negative error code on failure; for a populated ttm it never returns\nzero. Commit b2ed01e7ad3d (\"drm/ttm: Fix ttm_bo_swapout() infinite LRU\nwalk on swapout failure\") moved the bulk_move bookkeeping in\nttm_bo_swapout_cb() under \"if (!ret)\", so the\nttm_resource_del_bulk_move_unevictable() / ttm_resource_move_to_lru_tail()\npair is now skipped on every successful swapout. The equivalent change\nfor the shrinker in commit 1d59f36e95f7 (\"drm/ttm: Fix ttm_bo_shrink()\ninfinite LRU walk on backup failure\") tests \"lret > 0\", which is what\nwas intended here as well.\n\nBefore b2ed01e7ad3d the resource was taken off the bulk_move before the\nswapout; since then a swapped-out resource stays inside its BO's\nbulk_move range (and on the manager LRU) although it is unevictable.\nWhen it is later freed or the BO leaves the bulk_move\n(ttm_resource_free(), ttm_bo_set_bulk_move() via amdgpu_vm_bo_del()),\nttm_resource_del_bulk_move() skips it because of its\n!ttm_resource_unevictable() guard, so a range endpoint in pos->first /\npos->last is left pointing at freed memory. The next\nttm_lru_bulk_move_tail() or ttm_resource_add_bulk_move() on that cursor\nis a use-after-free, seen as the resv WARN in ttm_lru_bulk_move_add(),\n\"list_del corruption\" in ttm_resource_move_to_lru_tail() or a NULL\ndereference in ttm_resource_manager_next() -- minutes to hours after a\nhibernation, or at process exit / reboot following one. Samuel\nAinsworth's analysis of drm/amd issue 5387 (see Link) identified the\ndangling cursor; the missing removal at swapout time is the reason it\ndangles.\n\nTesting the condition for success restores the removal. On an AMD\nPhoenix APU (ASUS UM3406GA, gfx1103) running suspend-then-hibernate on\na 7.0.y stable kernel carrying the backport (Ubuntu 7.0.0-31) the bug\ncrashed 5 of 18 hibernation cycles; a function profile of one\nhibernation showed 336 ttm_tt_swapout() calls and zero\nttm_resource_del_bulk_move_unevictable() calls. With this change the\nremoval happens for every swapped-out resource and 12 further cycles\nwere clean."}],"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 attacker drives ttm_bo_swapout_cb() through local DRM render-node ioctls (amdgpu GEM_CREATE with VM_ALWAYS_VALID, then CS), with ttm_tt_populate() calling ttm_global_swapout() once ttm_pages_limit is exceeded, or through hibernation. No remote protocol carries any input.\nAC:L - Hibernation is not needed: the attacker allocates per-VM BOs past ttm_pages_limit to force swapout, closes the swapped BO so ttm_resource_free() frees a resource still referenced by the bulk_move cursor, then submits CS to run ttm_lru_bulk_move_tail(). Every step is the attacker's own action.\nPR:L - AMDGPU_GEM_CREATE, GEM_CLOSE and AMDGPU_CS are DRM_RENDER_ALLOW ioctls on /dev/dri/renderD*, open to an ordinary render-group or seat user without root or capabilities.\nUI:N - The attacker runs the whole sequence in their own process with their own buffer objects. No other user has to act.\nS:U - The freed ttm_resource and the corrupted manager LRU lists are kernel memory, so the impact stays within the kernel's own security authority.\nC:H - After ttm_resource_free() frees the swapped resource, bulk_move pos->first/pos->last still point at it, so a reallocated object can be read and walked as a ttm_resource by ttm_lru_bulk_move_tail() and the ttm_lru_next_res()/prev_res() helpers.\nI:H - list_bulk_move_tail() and ttm_lru_bulk_move_pos_tail() write list pointers through the dangling cursor into freed memory. The commit message reports this showing up as list_del corruption, a write primitive usable against a sprayed object.\nA:H - The use-after-free crashes the kernel through list_del corruption, the dma_resv WARN in ttm_lru_bulk_move_add(), or a NULL dereference in ttm_resource_manager_next(). The reporter crashed 5 of 18 hibernation cycles."}]}],"providerMetadata":{"dateUpdated":"2026-10-07T06:49:17.950Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/1169fe8c11ca45e3f91d59a73eb271d0ca8a7fb0"},{"url":"https://git.kernel.org/stable/c/3db7d7d583419f7b1f2e141e36418802dbb25cf8"}],"title":"drm/ttm: fix swapped-out resources never leaving their bulk_move range","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98166","datePublished":"2026-10-06T08:44:11.927Z","dateReserved":"2026-09-25T10:25:14.321Z","dateUpdated":"2026-10-07T06:49:17.950Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-06 09:17:58","lastModifiedDate":"2026-10-07 07:17:03","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":"98166","Ordinal":"1","Title":"drm/ttm: fix swapped-out resources never leaving their bulk_move","CVE":"CVE-2026-98166","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98166","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/ttm: fix swapped-out resources never leaving their bulk_move range\n\nttm_tt_swapout() returns the number of pages swapped out on success and\na negative error code on failure; for a populated ttm it never returns\nzero. Commit b2ed01e7ad3d (\"drm/ttm: Fix ttm_bo_swapout() infinite LRU\nwalk on swapout failure\") moved the bulk_move bookkeeping in\nttm_bo_swapout_cb() under \"if (!ret)\", so the\nttm_resource_del_bulk_move_unevictable() / ttm_resource_move_to_lru_tail()\npair is now skipped on every successful swapout. The equivalent change\nfor the shrinker in commit 1d59f36e95f7 (\"drm/ttm: Fix ttm_bo_shrink()\ninfinite LRU walk on backup failure\") tests \"lret > 0\", which is what\nwas intended here as well.\n\nBefore b2ed01e7ad3d the resource was taken off the bulk_move before the\nswapout; since then a swapped-out resource stays inside its BO's\nbulk_move range (and on the manager LRU) although it is unevictable.\nWhen it is later freed or the BO leaves the bulk_move\n(ttm_resource_free(), ttm_bo_set_bulk_move() via amdgpu_vm_bo_del()),\nttm_resource_del_bulk_move() skips it because of its\n!ttm_resource_unevictable() guard, so a range endpoint in pos->first /\npos->last is left pointing at freed memory. The next\nttm_lru_bulk_move_tail() or ttm_resource_add_bulk_move() on that cursor\nis a use-after-free, seen as the resv WARN in ttm_lru_bulk_move_add(),\n\"list_del corruption\" in ttm_resource_move_to_lru_tail() or a NULL\ndereference in ttm_resource_manager_next() -- minutes to hours after a\nhibernation, or at process exit / reboot following one. Samuel\nAinsworth's analysis of drm/amd issue 5387 (see Link) identified the\ndangling cursor; the missing removal at swapout time is the reason it\ndangles.\n\nTesting the condition for success restores the removal. On an AMD\nPhoenix APU (ASUS UM3406GA, gfx1103) running suspend-then-hibernate on\na 7.0.y stable kernel carrying the backport (Ubuntu 7.0.0-31) the bug\ncrashed 5 of 18 hibernation cycles; a function profile of one\nhibernation showed 336 ttm_tt_swapout() calls and zero\nttm_resource_del_bulk_move_unevictable() calls. With this change the\nremoval happens for every swapped-out resource and 12 further cycles\nwere clean.","Type":"Description","Title":"drm/ttm: fix swapped-out resources never leaving their bulk_move"}]}}}