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@HansKristian-Work HansKristian-Work commented Oct 23, 2025

Explores UB scenarios hit by Forza Horizon 5.

Only enable the test to be run on Windows and NV where it's known to work. RADV passes with https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38031, but we cannot assume that by default.

@HansKristian-Work HansKristian-Work force-pushed the use-before-alloc-stress-test branch from a074d15 to 365afd8 Compare October 24, 2025 09:29
@HansKristian-Work HansKristian-Work marked this pull request as ready for review October 24, 2025 09:30
@HansKristian-Work HansKristian-Work merged commit 0a3b126 into master Oct 31, 2025
6 checks passed
@HansKristian-Work HansKristian-Work deleted the use-before-alloc-stress-test branch October 31, 2025 11:18
FireBurn pushed a commit to FireBurn/linux that referenced this pull request Dec 17, 2025
Avoid a possible UAF in GPU recovery due to a race between
the sched timeout callback and the tdr work queue.

The gpu recovery function calls drm_sched_stop() and
later drm_sched_start().  drm_sched_start() restarts
the tdr queue which will eventually free the job.  If
the tdr queue frees the job before time out callback
completes, the job will be freed and we'll get a UAF
when accessing the pasid.  Cache it early to avoid the
UAF.

Example KASAN trace:
[  493.058141] BUG: KASAN: slab-use-after-free in amdgpu_device_gpu_recover+0x968/0x990 [amdgpu]
[  493.067530] Read of size 4 at addr ffff88b0ce3f794c by task kworker/u128:1/323
[  493.074892]
[  493.076485] CPU: 9 UID: 0 PID: 323 Comm: kworker/u128:1 Tainted: G            E       6.16.0-1289896.2.zuul.bf4f11df81c1410bbe901c4373305a31 #1 PREEMPT(voluntary)
[  493.076493] Tainted: [E]=UNSIGNED_MODULE
[  493.076495] Hardware name: TYAN B8021G88V2HR-2T/S8021GM2NR-2T, BIOS V1.03.B10 04/01/2019
[  493.076500] Workqueue: amdgpu-reset-dev drm_sched_job_timedout [gpu_sched]
[  493.076512] Call Trace:
[  493.076515]  <TASK>
[  493.076518]  dump_stack_lvl+0x64/0x80
[  493.076529]  print_report+0xce/0x630
[  493.076536]  ? _raw_spin_lock_irqsave+0x86/0xd0
[  493.076541]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  493.076545]  ? amdgpu_device_gpu_recover+0x968/0x990 [amdgpu]
[  493.077253]  kasan_report+0xb8/0xf0
[  493.077258]  ? amdgpu_device_gpu_recover+0x968/0x990 [amdgpu]
[  493.077965]  amdgpu_device_gpu_recover+0x968/0x990 [amdgpu]
[  493.078672]  ? __pfx_amdgpu_device_gpu_recover+0x10/0x10 [amdgpu]
[  493.079378]  ? amdgpu_coredump+0x1fd/0x4c0 [amdgpu]
[  493.080111]  amdgpu_job_timedout+0x642/0x1400 [amdgpu]
[  493.080903]  ? pick_task_fair+0x24e/0x330
[  493.080910]  ? __pfx_amdgpu_job_timedout+0x10/0x10 [amdgpu]
[  493.081702]  ? _raw_spin_lock+0x75/0xc0
[  493.081708]  ? __pfx__raw_spin_lock+0x10/0x10
[  493.081712]  drm_sched_job_timedout+0x1b0/0x4b0 [gpu_sched]
[  493.081721]  ? __pfx__raw_spin_lock_irq+0x10/0x10
[  493.081725]  process_one_work+0x679/0xff0
[  493.081732]  worker_thread+0x6ce/0xfd0
[  493.081736]  ? __pfx_worker_thread+0x10/0x10
[  493.081739]  kthread+0x376/0x730
[  493.081744]  ? __pfx_kthread+0x10/0x10
[  493.081748]  ? __pfx__raw_spin_lock_irq+0x10/0x10
[  493.081751]  ? __pfx_kthread+0x10/0x10
[  493.081755]  ret_from_fork+0x247/0x330
[  493.081761]  ? __pfx_kthread+0x10/0x10
[  493.081764]  ret_from_fork_asm+0x1a/0x30
[  493.081771]  </TASK>

Fixes: a72002c ("drm/amdgpu: Make use of drm_wedge_task_info")
Link: HansKristian-Work/vkd3d-proton#2670
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Suggested-by: Matthew Brost <[email protected]>
Reviewed-by: Srinivasan Shanmugam <[email protected]>
Reviewed-by: Lijo Lazar <[email protected]>
Reviewed-by: Christian König <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
FireBurn pushed a commit to FireBurn/linux that referenced this pull request Dec 18, 2025
Avoid a possible UAF in GPU recovery due to a race between
the sched timeout callback and the tdr work queue.

The gpu recovery function calls drm_sched_stop() and
later drm_sched_start().  drm_sched_start() restarts
the tdr queue which will eventually free the job.  If
the tdr queue frees the job before time out callback
completes, the job will be freed and we'll get a UAF
when accessing the pasid.  Cache it early to avoid the
UAF.

Example KASAN trace:
[  493.058141] BUG: KASAN: slab-use-after-free in amdgpu_device_gpu_recover+0x968/0x990 [amdgpu]
[  493.067530] Read of size 4 at addr ffff88b0ce3f794c by task kworker/u128:1/323
[  493.074892]
[  493.076485] CPU: 9 UID: 0 PID: 323 Comm: kworker/u128:1 Tainted: G            E       6.16.0-1289896.2.zuul.bf4f11df81c1410bbe901c4373305a31 #1 PREEMPT(voluntary)
[  493.076493] Tainted: [E]=UNSIGNED_MODULE
[  493.076495] Hardware name: TYAN B8021G88V2HR-2T/S8021GM2NR-2T, BIOS V1.03.B10 04/01/2019
[  493.076500] Workqueue: amdgpu-reset-dev drm_sched_job_timedout [gpu_sched]
[  493.076512] Call Trace:
[  493.076515]  <TASK>
[  493.076518]  dump_stack_lvl+0x64/0x80
[  493.076529]  print_report+0xce/0x630
[  493.076536]  ? _raw_spin_lock_irqsave+0x86/0xd0
[  493.076541]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  493.076545]  ? amdgpu_device_gpu_recover+0x968/0x990 [amdgpu]
[  493.077253]  kasan_report+0xb8/0xf0
[  493.077258]  ? amdgpu_device_gpu_recover+0x968/0x990 [amdgpu]
[  493.077965]  amdgpu_device_gpu_recover+0x968/0x990 [amdgpu]
[  493.078672]  ? __pfx_amdgpu_device_gpu_recover+0x10/0x10 [amdgpu]
[  493.079378]  ? amdgpu_coredump+0x1fd/0x4c0 [amdgpu]
[  493.080111]  amdgpu_job_timedout+0x642/0x1400 [amdgpu]
[  493.080903]  ? pick_task_fair+0x24e/0x330
[  493.080910]  ? __pfx_amdgpu_job_timedout+0x10/0x10 [amdgpu]
[  493.081702]  ? _raw_spin_lock+0x75/0xc0
[  493.081708]  ? __pfx__raw_spin_lock+0x10/0x10
[  493.081712]  drm_sched_job_timedout+0x1b0/0x4b0 [gpu_sched]
[  493.081721]  ? __pfx__raw_spin_lock_irq+0x10/0x10
[  493.081725]  process_one_work+0x679/0xff0
[  493.081732]  worker_thread+0x6ce/0xfd0
[  493.081736]  ? __pfx_worker_thread+0x10/0x10
[  493.081739]  kthread+0x376/0x730
[  493.081744]  ? __pfx_kthread+0x10/0x10
[  493.081748]  ? __pfx__raw_spin_lock_irq+0x10/0x10
[  493.081751]  ? __pfx_kthread+0x10/0x10
[  493.081755]  ret_from_fork+0x247/0x330
[  493.081761]  ? __pfx_kthread+0x10/0x10
[  493.081764]  ret_from_fork_asm+0x1a/0x30
[  493.081771]  </TASK>

Fixes: a72002c ("drm/amdgpu: Make use of drm_wedge_task_info")
Link: HansKristian-Work/vkd3d-proton#2670
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Suggested-by: Matthew Brost <[email protected]>
Reviewed-by: Srinivasan Shanmugam <[email protected]>
Reviewed-by: Lijo Lazar <[email protected]>
Reviewed-by: Christian König <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
(cherry picked from commit 20880a3)
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3 participants