drm/i915: Fix potential UAF in TTM object purge
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 14 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: drm/i915: Fix potential UAF in TTM object purge TLDR: The bo->ttm object might be changed by calling ttm_bo_validate(), move casting it to an i915_tt object later to actually get the right pointer. A user reported hitting the following bug under heavy use on DG2: [26620.095550] Oops: general protection fault, probably for non-canonical address 0xa56b6b6b6b6b6b8b: 0000 1 SMP NOPTI [26620.095556] CPU: 2 UID: 0 PID: 631 Comm: Xorg Not tainted 6.18.8 #1 PREEMPT(lazy) [26620.095558] Hardware name: ASRock B850M Steel Legend WiFi/B850M Steel Legend WiFi, BIOS 3.50 09/18/2025 [26620.095559] RIP: 0010:i915_ttm_purge+0x84/0x100 [i915] [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 [26620.095605] RSP: 0018:ffffc90005fd7430 EFLAGS: 00010282 [26620.095607] RAX: a56b6b6b6b6b6b6b RBX: ffff8881f46c3dc0 RCX: 0000000000000000 [26620.095608] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 00000000ffffffff [26620.095609] RBP: ffff888289610f00 R08: 0000000000000001 R09: ffff88823b022000 [26620.095609] R10: ffff888103029b28 R11: ffff8881fc7f3800 R12: ffff88810b6150d0 [26620.095609] R13: ffff888289610f00 R14: 0000000000000000 R15: ffff8881f46c3dc0 [26620.095610] FS: 00007f1004d86900(0000) GS:ffff88901c858000(0000) knlGS:0000000000000000 [26620.095611] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [26620.095611] CR2: 00007f0fdf489000 CR3: 000000035b0c1000 CR4: 0000000000750ef0 [26620.095612] PKRU: 55555554 [26620.095612] Call Trace: [26620.095615] <TASK> [26620.095615] i915_ttm_move+0x2b9/0x420 [i915] [26620.095642] ? ttm_tt_init+0x65/0x80 [ttm] [26620.095644] ? i915_ttm_tt_create+0xc6/0x150 [i915] [26620.095667] ttm_bo_handle_move_mem+0xb6/0x160 [ttm] [26620.095669] ttm_bo_evict+0x100/0x150 [ttm] [26620.095671] ? preempt_count_add+0x64/0xa0 [26620.095673] ? _raw_spin_lock+0xe/0x30 [26620.095675] ? _raw_spin_unlock+0xd/0x30 [26620.095675] ? i915_gem_object_evictable+0xb7/0xd0 [i915] [26620.095704] ttm_bo_evict_cb+0x6e/0xd0 [ttm] [26620.095705] ttm_lru_walk_for_evict+0xa6/0x200 [ttm] [26620.095708] ttm_bo_alloc_resource+0x185/0x4f0 [ttm] [26620.095709] ? init_object+0x62/0xd0 [26620.095712] ttm_bo_validate+0x7a/0x180 [ttm] [26620.095713] ? _raw_spin_unlock_irqrestore+0x16/0x30 [26620.095714] __i915_ttm_get_pages+0xb0/0x170 [i915] [26620.095737] i915_ttm_get_pages+0x9f/0x150 [i915] [26620.095759] ? i915_gem_do_execbuffer+0xedc/0x2b40 [i915] [26620.095786] ? alloc_debug_processing+0xd0/0x100 [26620.095787] ? _raw_spin_unlock_irqrestore+0x16/0x30 [26620.095788] ? i915_vma_instance+0xa0/0x4e0 [i915] [26620.095822] __i915_gem_object_get_pages+0x2f/0x40 [i915] [26620.095848] i915_vma_pin_ww+0x706/0x980 [i915] [26620.095875] ? i915_gem_do_execbuffer+0xedc/0x2b40 [i915] [26620.095904] eb_validate_vmas+0x170/0xa00 [i915] [26620.095930] i915_gem_do_execbuffer+0x1201/0x2b40 [i915] [26620.095953] ? alloc_debug_processing+0xd0/0x100 [26620.095954] ? _raw_spin_unlock_irqrestore+0x16/0x30 [26620.095955] ? i915_gem_execbuffer2_ioctl+0xc9/0x240 [i915] [26620.095977] ? __wake_up_sync_key+0x32/0x50 [26620.095979] ? i915_gem_execbuffer2_ioctl+0xc9/0x240 [i915] [26620.096001] ? __slab_alloc.isra.0+0x67/0xc0 [26620.096003] i915_gem_execbuffer2_ioctl+0x11a/0x240 [i915] Results from decode_stacktrace.sh pointed to dereference of a file pointer field of a i915 TTM page vector container associated with an object being purged on eviction. That path is taken when the object is marked as no longer needed. Code analysis revealed a possibility of the i915 TTM page vector container being replaced with a new instance inside a function that purges content of the object, should it be still busy. That function is called, indirectly via a more general function that changes the object's placement and caching policy, ---truncated---
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.17 and later | 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 5.17 and later Fixed in 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 7.1 Patch available CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.17 to before 6.1.176; 6.2 to before 6.6.143; 6.7 to before 6.12.93; 6.13 to before 6.18.35; 6.19 to before 7.0.12 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | 7.1 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | 7.1 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | 7.1 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* | 7.1 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* | 7.1 rc5 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.17 to before 6.1.176; 6.2 to before 6.6.143; 6.7 to before 6.12.93; 6.13 to before 6.18.35; 6.19 to before 7.0.12 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* Versions 7.1 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* Versions 7.1 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* Versions 7.1 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* Versions 7.1 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* Versions 7.1 rc5 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 7.1
Red Hat 4 advisories
- RHSA-2026:57252 Released 2026-08-20 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.41.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.41.1.el9_8, kernel-64k-devel-5.14.0-687.41.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.41.1.el9_8, kernel-64k-5.14.0-687.41.1.el9_8, kernel-64k-core-5.14.0-687.41.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.41.1.el9_8, libperf-5.14.0-687.41.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.41.1.el9_8, kernel-rt-64k-5.14.0-687.41.1.el9_8, kernel-rt-64k-core-5.14.0-687.41.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.41.1.el9_8, kernel-rt-core-5.14.0-687.41.1.el9_8, kernel-rt-debug-5.14.0-687.41.1.el9_8 +9
- RHSA-2026:57251 Released 2026-08-20 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.49.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.49.1.el10_2, kernel-64k-devel-6.12.0-211.49.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.49.1.el10_2, kernel-64k-6.12.0-211.49.1.el10_2, kernel-64k-core-6.12.0-211.49.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.49.1.el10_2, libperf-6.12.0-211.49.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.49.1.el10_2, kernel-rt-64k-6.12.0-211.49.1.el10_2, kernel-rt-64k-core-6.12.0-211.49.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.49.1.el10_2, kernel-rt-core-6.12.0-211.49.1.el10_2, kernel-rt-debug-6.12.0-211.49.1.el10_2 +9
- RHSA-2026:55764 Released 2026-08-17 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.156.1.el8_10, kernel-4.18.0-553.156.1.el8_10, kernel-abi-stablelists-4.18.0-553.156.1.el8_10 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.156.1.el8_10
Show 1 more Red Hat advisories
- RHSA-2026:55765 Released 2026-08-17 · Red Hat rating Importantkernel-rt security, bug fix, and enhancement update
- Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-core-4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-debug-4.18.0-553.156.1.rt7.497.el8_10 +9
- Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-core-4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-debug-4.18.0-553.156.1.rt7.497.el8_10 +7
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | — |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:57251 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:57252 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:57251 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:55764 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:57252 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2026:55764 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:57251 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:57252 |
| Red Hat Enterprise Linux NFV (v. 8) | Fixed | RHSA-2026:55765 |
| Red Hat Enterprise Linux RT (v. 8) | Fixed | RHSA-2026:55765 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:57251 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:57252 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:57251 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:57252 |
Not affected: 1 product
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-63884
- 2026-10-03 Alias added: GHSA-8mf8-7jc8-gw2x
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-19 Weakness changed · CISA ADP
References
Patch 6
- 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
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Sources
- CVE-2026-63884 · CVE Program
- CVE-2026-63884 · NVD
- FIRST EPSS
- GHSA-8mf8-7jc8-gw2x · GitHub Advisory Database · CC BY 4.0
- CVE-2026-63884 · Red Hat security data · CC BY 4.0
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