NuytsTech Security

CVE-2025-68203

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

drm/amdgpu: fix lock warning in amdgpu_userq_fence_driver_process

Fix a potential deadlock caused by inconsistent spinlock usage
between interrupt and process contexts in the userq fence driver.

The issue occurs when amdgpu_userq_fence_driver_process() is called
from both:
– Interrupt context: gfx_v11_0_eop_irq() -> amdgpu_userq_fence_driver_process()
– Process context: amdgpu_eviction_fence_suspend_worker() ->
amdgpu_userq_fence_driver_force_completion() -> amdgpu_userq_fence_driver_process()

In interrupt context, the spinlock was acquired without disabling
interrupts, leaving it in {IN-HARDIRQ-W} state. When the same lock
is acquired in process context, the kernel detects inconsistent
locking since the process context acquisition would enable interrupts
while holding a lock previously acquired in interrupt context.

Kernel log shows:
[ 4039.310790] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
[ 4039.310804] kworker/7:2/409 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 4039.310818] ffff9284e1bed000 (&fence_drv->fence_list_lock){?…}-{3:3},
[ 4039.310993] {IN-HARDIRQ-W} state was registered at:
[ 4039.311004] lock_acquire+0xc6/0x300
[ 4039.311018] _raw_spin_lock+0x39/0x80
[ 4039.311031] amdgpu_userq_fence_driver_process.part.0+0x30/0x180 [amdgpu]
[ 4039.311146] amdgpu_userq_fence_driver_process+0x17/0x30 [amdgpu]
[ 4039.311257] gfx_v11_0_eop_irq+0x132/0x170 [amdgpu]

Fix by using spin_lock_irqsave()/spin_unlock_irqrestore() to properly
manage interrupt state regardless of calling context.

(cherry picked from commit ded3ad780cf97a04927773c4600823b84f7f3cc2)

More information : https://git.kernel.org/stable/c/1ad70a06d7e91c378b346a3718c81abb50a74b74

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