{"id":"CVE-2026-80919","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-80919","generatedAt":"2026-10-28T05:01:41.525Z","title":"In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix recursive ww_mutex acquire in amdgpu_devcoredump_format When dumping IB contents from a hung job, amdgpu_devcoredump_format() acquired the VM root PD's reservation via…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu: fix recursive ww_mutex acquire in amdgpu_devcoredump_format\n\nWhen dumping IB contents from a hung job, amdgpu_devcoredump_format()\nacquired the VM root PD's reservation via amdgpu_vm_lock_by_pasid() and\nthen, for each IB, called amdgpu_bo_reserve() on the BO backing the IB.\nBoth reservations are reservation_ww_class_mutex objects and neither\nused a ww_acquire_ctx, which trips lockdep:\n\n  WARNING: possible recursive locking detected\n  --------------------------------------------\n  kworker/u128:0 is trying to acquire lock:\n  ffff88838b16e1f0 (reservation_ww_class_mutex){+.+.}-{4:4},\n    at: amdgpu_devcoredump_format+0x1594/0x23f0 [amdgpu]\n\n  but task is already holding lock:\n  ffff8882f82681f0 (reservation_ww_class_mutex){+.+.}-{4:4},\n    at: amdgpu_devcoredump_format+0x1594/0x23f0 [amdgpu]\n\n   Possible unsafe locking scenario:\n         CPU0\n         ----\n    lock(reservation_ww_class_mutex);\n    lock(reservation_ww_class_mutex);\n\n   *** DEADLOCK ***\n   May be due to missing lock nesting notation\n\n  Workqueue: events_unbound amdgpu_devcoredump_deferred_work [amdgpu]\n  Call Trace:\n   __ww_mutex_lock.constprop.0\n   ww_mutex_lock\n   amdgpu_bo_reserve\n   amdgpu_devcoredump_format+0x1594 [amdgpu]\n   amdgpu_devcoredump_deferred_work+0xea [amdgpu]\n\nThe two reservations are on different BOs in the captured trace, so the\nsplat is a lockdep-correctness warning, not an observed deadlock. It\nbecomes a real self-deadlock whenever the IB BO shares its dma_resv with\nthe root PD (the always-valid case, see amdgpu_vm_is_bo_always_valid()):\namdgpu_bo_reserve(abo) re-acquires the same ww_mutex without a ticket\nand blocks forever. With amdgpu.gpu_recovery=0 the timeout handler\nrefires every ~2 s and each invocation produces this splat, drowning the\nkernel ring buffer.\n\nNow that amdgpu_vm_lock_by_pasid() takes a drm_exec context, move the IB\ndumping into a separate helper that locks the root PD and every IB BO\ntogether in a single drm_exec ticket. DRM_EXEC_IGNORE_DUPLICATES handles\nIB BOs that share a dma_resv (e.g. always-valid BOs, or two IBs backed\nby the same BO). Every lock is now a top-level acquire under one\nww_acquire_ctx, so the recursive ww_mutex condition is gone, and the\nper-IB amdgpu_bo_reserve()/amdgpu_bo_unref() dance -- including a BO\nrefcount leak on the amdgpu_bo_reserve() failure path -- is removed.\n\n(cherry picked from commit d6bf4242731219ee08ce54c365631e395486651e)","published":"2026-09-09T17:17:47.000Z","lastModified":"2026-09-09T17:17:47.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":null,"cwe":[],"affected":[],"epss":{"score":0.00198,"percentile":0.0945,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"unknown","text":"Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/4e9b4dee0777ec9c835a4746e2d30382dd9d1044","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7152b248dc3c8d5fa8629e99ed5655dd41b51562","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80919","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}