{"id":"CVE-2026-63884","state":"PUBLISHED","title":"drm/i915: Fix potential UAF in TTM object purge","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/i915: Fix potential UAF in TTM object purge\n\nTLDR: The bo->ttm object might be changed by calling ttm_bo_validate(),\n      move casting it to an i915_tt object later to actually get the right\n      pointer.\n\nA user reported hitting the following bug under heavy use on DG2:\n\n[26620.095550] Oops: general protection fault, probably for non-canonical address 0xa56b6b6b6b6b6b8b: 0000 1 SMP NOPTI\n[26620.095556] CPU: 2 UID: 0 PID: 631 Comm: Xorg Not tainted 6.18.8 #1 PREEMPT(lazy)\n[26620.095558] Hardware name: ASRock B850M Steel Legend WiFi/B850M Steel Legend WiFi, BIOS 3.50 09/18/2025\n[26620.095559] RIP: 0010:i915_ttm_purge+0x84/0x100 [i915]\n[26620.095604] Code: 00 00 00 48 8d 54 24 10 48 89 e6 48 89 fb e8 83 aa ae ff 85 c0 75 6f 48 83 bb a8 01 00 00 00 74 2c 48 8b 45 78 48 85 c0 74 23 <48> 8b 78 20 48 c7 c2 ff ff ff ff 31 f6 e8 7a 73 e3 e0 48 8b 7d 78\n[26620.095605] RSP: 0018:ffffc90005fd7430 EFLAGS: 00010282\n[26620.095607] RAX: a56b6b6b6b6b6b6b RBX: ffff8881f46c3dc0 RCX: 0000000000000000\n[26620.095608] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 00000000ffffffff\n[26620.095609] RBP: ffff888289610f00 R08: 0000000000000001 R09: ffff88823b022000\n[26620.095609] R10: ffff888103029b28 R11: ffff8881fc7f3800 R12: ffff88810b6150d0\n[26620.095609] R13: ffff888289610f00 R14: 0000000000000000 R15: ffff8881f46c3dc0\n[26620.095610] FS: 00007f1004d86900(0000) GS:ffff88901c858000(0000) knlGS:0000000000000000\n[26620.095611] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[26620.095611] CR2: 00007f0fdf489000 CR3: 000000035b0c1000 CR4: 0000000000750ef0\n[26620.095612] PKRU: 55555554\n[26620.095612] Call Trace:\n[26620.095615] <TASK>\n[26620.095615] i915_ttm_move+0x2b9/0x420 [i915]\n[26620.095642] ? ttm_tt_init+0x65/0x80 [ttm]\n[26620.095644] ? i915_ttm_tt_create+0xc6/0x150 [i915]\n[26620.095667] ttm_bo_handle_move_mem+0xb6/0x160 [ttm]\n[26620.095669] ttm_bo_evict+0x100/0x150 [ttm]\n[26620.095671] ? preempt_count_add+0x64/0xa0\n[26620.095673] ? _raw_spin_lock+0xe/0x30\n[26620.095675] ? _raw_spin_unlock+0xd/0x30\n[26620.095675] ? i915_gem_object_evictable+0xb7/0xd0 [i915]\n[26620.095704] ttm_bo_evict_cb+0x6e/0xd0 [ttm]\n[26620.095705] ttm_lru_walk_for_evict+0xa6/0x200 [ttm]\n[26620.095708] ttm_bo_alloc_resource+0x185/0x4f0 [ttm]\n[26620.095709] ? init_object+0x62/0xd0\n[26620.095712] ttm_bo_validate+0x7a/0x180 [ttm]\n[26620.095713] ? _raw_spin_unlock_irqrestore+0x16/0x30\n[26620.095714] __i915_ttm_get_pages+0xb0/0x170 [i915]\n[26620.095737] i915_ttm_get_pages+0x9f/0x150 [i915]\n[26620.095759] ? i915_gem_do_execbuffer+0xedc/0x2b40 [i915]\n[26620.095786] ? alloc_debug_processing+0xd0/0x100\n[26620.095787] ? _raw_spin_unlock_irqrestore+0x16/0x30\n[26620.095788] ? i915_vma_instance+0xa0/0x4e0 [i915]\n[26620.095822] __i915_gem_object_get_pages+0x2f/0x40 [i915]\n[26620.095848] i915_vma_pin_ww+0x706/0x980 [i915]\n[26620.095875] ? i915_gem_do_execbuffer+0xedc/0x2b40 [i915]\n[26620.095904] eb_validate_vmas+0x170/0xa00 [i915]\n[26620.095930] i915_gem_do_execbuffer+0x1201/0x2b40 [i915]\n[26620.095953] ? alloc_debug_processing+0xd0/0x100\n[26620.095954] ? _raw_spin_unlock_irqrestore+0x16/0x30\n[26620.095955] ? i915_gem_execbuffer2_ioctl+0xc9/0x240 [i915]\n[26620.095977] ? __wake_up_sync_key+0x32/0x50\n[26620.095979] ? i915_gem_execbuffer2_ioctl+0xc9/0x240 [i915]\n[26620.096001] ? __slab_alloc.isra.0+0x67/0xc0\n[26620.096003] i915_gem_execbuffer2_ioctl+0x11a/0x240 [i915]\n\nResults from decode_stacktrace.sh pointed to dereference of a file pointer\nfield of a i915 TTM page vector container associated with an object being\npurged on eviction.  That path is taken when the object is marked as no\nlonger needed.\n\nCode analysis revealed a possibility of the i915 TTM page vector container\nbeing replaced with a new instance inside a function that purges content\nof the object, should it be still busy.  That function is called,\nindirectly via a more general function that changes the object's placement\nand caching policy,\n---truncated---","publishedAt":"2026-07-19T14:54:57.520Z","updatedAt":"2026-10-19T20:17:54.188Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"df73f3bc731af1c39ac5405bc59c4e7c6f8e9117","versionType":"git"},{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"28b22dbaf407598cb3bb1d2c586a6f8018690ac2","versionType":"git"},{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"073bcbc95e9648c976da1654c7590a8d6ee12c2d","versionType":"git"},{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"c9ae7e7e3bc98615364313b08d7acea5239ded0b","versionType":"git"},{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"a29654d451bbffe63d584a4cf64ad0efce6bcf1c","versionType":"git"},{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"5c4063c87a619e4df954c179d24628636f5db15f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/i915/gem/i915_gem_ttm.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.93","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.35","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.12","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/i915/gem/i915_gem_ttm.c"]}],"references":["https://git.kernel.org/stable/c/df73f3bc731af1c39ac5405bc59c4e7c6f8e9117","https://git.kernel.org/stable/c/28b22dbaf407598cb3bb1d2c586a6f8018690ac2","https://git.kernel.org/stable/c/073bcbc95e9648c976da1654c7590a8d6ee12c2d","https://git.kernel.org/stable/c/c9ae7e7e3bc98615364313b08d7acea5239ded0b","https://git.kernel.org/stable/c/a29654d451bbffe63d584a4cf64ad0efce6bcf1c","https://git.kernel.org/stable/c/5c4063c87a619e4df954c179d24628636f5db15f"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63884.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63884","state":"PUBLISHED","datePublished":"2026-07-19T14:54:57.520Z","dateUpdated":"2026-10-19T20:17:54.188Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.018Z"},"containers":{"cna":{"title":"drm/i915: Fix potential UAF in TTM object purge","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/i915: Fix potential UAF in TTM object purge\n\nTLDR: The bo->ttm object might be changed by calling ttm_bo_validate(),\n      move casting it to an i915_tt object later to actually get the right\n      pointer.\n\nA user reported hitting the following bug under heavy use on DG2:\n\n[26620.095550] Oops: general protection fault, probably for non-canonical address 0xa56b6b6b6b6b6b8b: 0000 1 SMP NOPTI\n[26620.095556] CPU: 2 UID: 0 PID: 631 Comm: Xorg Not tainted 6.18.8 #1 PREEMPT(lazy)\n[26620.095558] Hardware name: ASRock B850M Steel Legend WiFi/B850M Steel Legend WiFi, BIOS 3.50 09/18/2025\n[26620.095559] RIP: 0010:i915_ttm_purge+0x84/0x100 [i915]\n[26620.095604] Code: 00 00 00 48 8d 54 24 10 48 89 e6 48 89 fb e8 83 aa ae ff 85 c0 75 6f 48 83 bb a8 01 00 00 00 74 2c 48 8b 45 78 48 85 c0 74 23 <48> 8b 78 20 48 c7 c2 ff ff ff ff 31 f6 e8 7a 73 e3 e0 48 8b 7d 78\n[26620.095605] RSP: 0018:ffffc90005fd7430 EFLAGS: 00010282\n[26620.095607] RAX: a56b6b6b6b6b6b6b RBX: ffff8881f46c3dc0 RCX: 0000000000000000\n[26620.095608] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 00000000ffffffff\n[26620.095609] RBP: ffff888289610f00 R08: 0000000000000001 R09: ffff88823b022000\n[26620.095609] R10: ffff888103029b28 R11: ffff8881fc7f3800 R12: ffff88810b6150d0\n[26620.095609] R13: ffff888289610f00 R14: 0000000000000000 R15: ffff8881f46c3dc0\n[26620.095610] FS: 00007f1004d86900(0000) GS:ffff88901c858000(0000) knlGS:0000000000000000\n[26620.095611] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[26620.095611] CR2: 00007f0fdf489000 CR3: 000000035b0c1000 CR4: 0000000000750ef0\n[26620.095612] PKRU: 55555554\n[26620.095612] Call Trace:\n[26620.095615] <TASK>\n[26620.095615] i915_ttm_move+0x2b9/0x420 [i915]\n[26620.095642] ? ttm_tt_init+0x65/0x80 [ttm]\n[26620.095644] ? i915_ttm_tt_create+0xc6/0x150 [i915]\n[26620.095667] ttm_bo_handle_move_mem+0xb6/0x160 [ttm]\n[26620.095669] ttm_bo_evict+0x100/0x150 [ttm]\n[26620.095671] ? preempt_count_add+0x64/0xa0\n[26620.095673] ? _raw_spin_lock+0xe/0x30\n[26620.095675] ? _raw_spin_unlock+0xd/0x30\n[26620.095675] ? i915_gem_object_evictable+0xb7/0xd0 [i915]\n[26620.095704] ttm_bo_evict_cb+0x6e/0xd0 [ttm]\n[26620.095705] ttm_lru_walk_for_evict+0xa6/0x200 [ttm]\n[26620.095708] ttm_bo_alloc_resource+0x185/0x4f0 [ttm]\n[26620.095709] ? init_object+0x62/0xd0\n[26620.095712] ttm_bo_validate+0x7a/0x180 [ttm]\n[26620.095713] ? _raw_spin_unlock_irqrestore+0x16/0x30\n[26620.095714] __i915_ttm_get_pages+0xb0/0x170 [i915]\n[26620.095737] i915_ttm_get_pages+0x9f/0x150 [i915]\n[26620.095759] ? i915_gem_do_execbuffer+0xedc/0x2b40 [i915]\n[26620.095786] ? alloc_debug_processing+0xd0/0x100\n[26620.095787] ? _raw_spin_unlock_irqrestore+0x16/0x30\n[26620.095788] ? i915_vma_instance+0xa0/0x4e0 [i915]\n[26620.095822] __i915_gem_object_get_pages+0x2f/0x40 [i915]\n[26620.095848] i915_vma_pin_ww+0x706/0x980 [i915]\n[26620.095875] ? i915_gem_do_execbuffer+0xedc/0x2b40 [i915]\n[26620.095904] eb_validate_vmas+0x170/0xa00 [i915]\n[26620.095930] i915_gem_do_execbuffer+0x1201/0x2b40 [i915]\n[26620.095953] ? alloc_debug_processing+0xd0/0x100\n[26620.095954] ? _raw_spin_unlock_irqrestore+0x16/0x30\n[26620.095955] ? i915_gem_execbuffer2_ioctl+0xc9/0x240 [i915]\n[26620.095977] ? __wake_up_sync_key+0x32/0x50\n[26620.095979] ? i915_gem_execbuffer2_ioctl+0xc9/0x240 [i915]\n[26620.096001] ? __slab_alloc.isra.0+0x67/0xc0\n[26620.096003] i915_gem_execbuffer2_ioctl+0x11a/0x240 [i915]\n\nResults from decode_stacktrace.sh pointed to dereference of a file pointer\nfield of a i915 TTM page vector container associated with an object being\npurged on eviction.  That path is taken when the object is marked as no\nlonger needed.\n\nCode analysis revealed a possibility of the i915 TTM page vector container\nbeing replaced with a new instance inside a function that purges content\nof the object, should it be still busy.  That function is called,\nindirectly via a more general function that changes the object's placement\nand caching policy,\n---truncated---"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"df73f3bc731af1c39ac5405bc59c4e7c6f8e9117","versionType":"git"},{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"28b22dbaf407598cb3bb1d2c586a6f8018690ac2","versionType":"git"},{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"073bcbc95e9648c976da1654c7590a8d6ee12c2d","versionType":"git"},{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"c9ae7e7e3bc98615364313b08d7acea5239ded0b","versionType":"git"},{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"a29654d451bbffe63d584a4cf64ad0efce6bcf1c","versionType":"git"},{"version":"7ae034590ceaefd4d37465e3434877acfbadf411","status":"affected","lessThan":"5c4063c87a619e4df954c179d24628636f5db15f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/i915/gem/i915_gem_ttm.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.93","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.35","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.12","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/i915/gem/i915_gem_ttm.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/df73f3bc731af1c39ac5405bc59c4e7c6f8e9117"},{"url":"https://git.kernel.org/stable/c/28b22dbaf407598cb3bb1d2c586a6f8018690ac2"},{"url":"https://git.kernel.org/stable/c/073bcbc95e9648c976da1654c7590a8d6ee12c2d"},{"url":"https://git.kernel.org/stable/c/c9ae7e7e3bc98615364313b08d7acea5239ded0b"},{"url":"https://git.kernel.org/stable/c/a29654d451bbffe63d584a4cf64ad0efce6bcf1c"},{"url":"https://git.kernel.org/stable/c/5c4063c87a619e4df954c179d24628636f5db15f"}],"metrics":[{"cvssV3_1":{"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"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only through local DRM ioctls on the Intel GPU render node (notably I915_GEM_EXECBUFFER2 and I915_GEM_MADVISE); there is no network, adjacent-radio, or physical-access entry path.\nAC:L - An attacker controls the triggering workload (concurrent execbuffers, madvise DONTNEED, and GPU memory pressure to force eviction), and the UAF is a deterministic stale-pointer bug rather than a race against uncontrollable system state.\nPR:L - Exploitation requires only access to the DRM render node and standard unprivileged GEM ioctls (DRM_RENDER_ALLOW); no CAP_SYS_ADMIN, DRM master, or init-namespace root is needed.\nUI:N - No victim interaction is required beyond the attacker (or a compromised local GPU client) issuing its own ioctl submissions to the render node.\nS:U - Successful exploitation yields kernel memory corruption and local privilege escalation within the same kernel security authority; it does not constitute a VM escape or IOMMU/DMA boundary bypass.\nC:H - This is a kernel heap use-after-free on a freed i915_ttm_tt structure; attacker-controlled reuse of the freed object can provide arbitrary kernel memory read primitives.\nI:H - UAF on the i915_ttm_tt/filp path enables heap grooming and corrupting kernel objects, providing a standard path to arbitrary kernel write and code execution.\nA:H - The vulnerability was observed causing a kernel general protection fault/oops under real workloads, and UAF in this path can reliably crash or hang the system even before full exploitation."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:36:53.207Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.12.93"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.18.35"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"7.0.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-63884","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:32:49.875473Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:17:54.188Z"}}]}}}