CVE-2025-68793

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu: fix a job->pasid access race in gpu recovery

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 drmschedstop() and later drmschedstart(). drmschedstart() 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 amdgpudevicegpurecover+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]=UNSIGNEDMODULE [ 493.076495] Hardware name: TYAN B8021G88V2HR-2T/S8021GM2NR-2T, BIOS V1.03.B10 04/01/2019 [ 493.076500] Workqueue: amdgpu-reset-dev drmschedjobtimedout [gpusched] [ 493.076512] Call Trace: [ 493.076515] <TASK> [ 493.076518] dumpstacklvl+0x64/0x80 [ 493.076529] printreport+0xce/0x630 [ 493.076536] ? rawspinlockirqsave+0x86/0xd0 [ 493.076541] ? pfxrawspinlockirqsave+0x10/0x10 [ 493.076545] ? amdgpudevicegpurecover+0x968/0x990 [amdgpu] [ 493.077253] kasanreport+0xb8/0xf0 [ 493.077258] ? amdgpudevicegpurecover+0x968/0x990 [amdgpu] [ 493.077965] amdgpudevicegpurecover+0x968/0x990 [amdgpu] [ 493.078672] ? __pfxamdgpudevice_gpurecover+0x10/0x10 [amdgpu] [ 493.079378] ? amdgpucoredump+0x1fd/0x4c0 [amdgpu] [ 493.080111] amdgpujobtimedout+0x642/0x1400 [amdgpu] [ 493.080903] ? picktaskfair+0x24e/0x330 [ 493.080910] ? __pfxamdgpujobtimedout+0x10/0x10 [amdgpu] [ 493.081702] ? rawspinlock+0x75/0xc0 [ 493.081708] ? pfxrawspinlock+0x10/0x10 [ 493.081712] drmschedjobtimedout+0x1b0/0x4b0 [gpusched] [ 493.081721] ? pfxrawspinlockirq+0x10/0x10 [ 493.081725] processonework+0x679/0xff0 [ 493.081732] workerthread+0x6ce/0xfd0 [ 493.081736] ? __pfxworkerthread+0x10/0x10 [ 493.081739] kthread+0x376/0x730 [ 493.081744] ? __pfxkthread+0x10/0x10 [ 493.081748] ? pfxrawspinlockirq+0x10/0x10 [ 493.081751] ? __pfxkthread+0x10/0x10 [ 493.081755] retfrom_fork+0x247/0x330 [ 493.081761] ? __pfxkthread+0x10/0x10 [ 493.081764] retfromforkasm+0x1a/0x30 [ 493.081771] </TASK>

(cherry picked from commit 20880a3fd5dd7bca1a079534cf6596bda92e107d)