linux-stable.git/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c, branch linux-rolling-lts

drm/amdgpu: add upper bound check on user inputs in wait ioctl

2026-03-19T15:08:32+00:00

commit 64ac7c09fc44985ec9bb6a9db740899fa40ca613 upstream.

Huge input values in amdgpu_userq_wait_ioctl can lead to a OOM and
could be exploited.

So check these input value against AMDGPU_USERQ_MAX_HANDLES
which is big enough value for genuine use cases and could
potentially avoid OOM.

v2: squash in Srini's fix

Signed-off-by: Sunil Khatri 
Reviewed-by: Christian König 
Signed-off-by: Alex Deucher 
(cherry picked from commit fcec012c664247531aed3e662f4280ff804d1476)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amdgpu/userq: Fix reference leak in amdgpu_userq_wait_ioctl

2026-03-19T15:08:32+00:00

commit 49abfa812617a7f2d0132c70d23ac98b389c6ec1 upstream.

Drop reference to syncobj and timeline fence when aborting the ioctl due
output array being too small.

Reviewed-by: Alex Deucher 
Signed-off-by: Tvrtko Ursulin 
Fixes: a292fdecd728 ("drm/amdgpu: Implement userqueue signal/wait IOCTL")
Cc: Arunpravin Paneer Selvam 
Cc: Christian König 
Cc: Alex Deucher 
Signed-off-by: Alex Deucher 
(cherry picked from commit 68951e9c3e6bb22396bc42ef2359751c8315dd27)
Cc:  # v6.16+
Signed-off-by: Greg Kroah-Hartman

drm/amdgpu: add upper bound check on user inputs in signal ioctl

2026-03-19T15:08:32+00:00

commit ea78f8c68f4f6211c557df49174c54d167821962 upstream.

Huge input values in amdgpu_userq_signal_ioctl can lead to a OOM and
could be exploited.

So check these input value against AMDGPU_USERQ_MAX_HANDLES
which is big enough value for genuine use cases and could
potentially avoid OOM.

Signed-off-by: Sunil Khatri 
Reviewed-by: Christian König 
Signed-off-by: Alex Deucher 
(cherry picked from commit be267e15f99bc97cbe202cd556717797cdcf79a5)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amdgpu/userq: Do not allow userspace to trivially triger kernel warnings

2026-03-12T11:09:18+00:00

[ Upstream commit 7b7d7693a55d606d700beb9549c9f7f0e5d9c24f ]

Userspace can either deliberately pass in the too small num_fences, or the
required number can legitimately grow between the two calls to the userq
wait ioctl. In both cases we do not want the emit the kernel warning
backtrace since nothing is wrong with the kernel and userspace will simply
get an errno reported back. So lets simply drop the WARN_ONs.

Reviewed-by: Alex Deucher 
Signed-off-by: Tvrtko Ursulin 
Fixes: a292fdecd728 ("drm/amdgpu: Implement userqueue signal/wait IOCTL")
Cc: Arunpravin Paneer Selvam 
Cc: Christian König 
Cc: Alex Deucher 
Reviewed-by: Christian König 
Signed-off-by: Alex Deucher 
(cherry picked from commit 2c333ea579de6cc20ea7bc50e9595ef72863e65c)
Signed-off-by: Sasha Levin

drm/amdgpu: make sure userqs are enabled in userq IOCTLs

2026-01-23T10:21:31+00:00

commit b6dff005fcf32dd072f6f2d08ca461394a21bd4f upstream.

These IOCTLs shouldn't be called when userqs are not
enabled.  Make sure they are enabled before executing
the IOCTLs.

Reviewed-by: Christian König 
Signed-off-by: Alex Deucher 
(cherry picked from commit d967509651601cddce7ff2a9f09479f3636f684d)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amdgpu/userq: Fix fence reference leak on queue teardown v2

2026-01-23T10:21:19+00:00

[ Upstream commit b2426a211dba6432e32a2e70e9183c6e134475c6 ]

The user mode queue keeps a pointer to the most recent fence in
userq->last_fence. This pointer holds an extra dma_fence reference.

When the queue is destroyed, we free the fence driver and its xarray,
but we forgot to drop the last_fence reference.

Because of the missing dma_fence_put(), the last fence object can stay
alive when the driver unloads. This leaves an allocated object in the
amdgpu_userq_fence slab cache and triggers

This is visible during driver unload as:

  BUG amdgpu_userq_fence: Objects remaining on __kmem_cache_shutdown()
  kmem_cache_destroy amdgpu_userq_fence: Slab cache still has objects
  Call Trace:
    kmem_cache_destroy
    amdgpu_userq_fence_slab_fini
    amdgpu_exit
    __do_sys_delete_module

Fix this by putting userq->last_fence and clearing the pointer during
amdgpu_userq_fence_driver_free().

This makes sure the fence reference is released and the slab cache is
empty when the module exits.

v2: Update to only release userq->last_fence with dma_fence_put()
    (Christian)

Fixes: edc762a51c71 ("drm/amdgpu/userq: move some code around")
Cc: Alex Deucher 
Cc: Christian König 
Signed-off-by: Srinivasan Shanmugam 
Reviewed-by: Christian König 
Signed-off-by: Alex Deucher 
(cherry picked from commit 8e051e38a8d45caf6a866d4ff842105b577953bb)
Signed-off-by: Sasha Levin

drm/amdgpu: fix lock warning in amdgpu_userq_fence_driver_process

2025-11-12T03:50:22+00:00

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.

Reviewed-by: Christian König 
Signed-off-by: Jesse Zhang 
Signed-off-by: Alex Deucher 
(cherry picked from commit ded3ad780cf97a04927773c4600823b84f7f3cc2)
Cc: stable@vger.kernel.org

drm/amdgpu: Fix fence signaling race condition in userqueue

2025-09-25T19:53:23+00:00

This commit fixes a potential race condition in the userqueue fence
signaling mechanism by replacing dma_fence_is_signaled_locked() with
dma_fence_is_signaled().

The issue occurred because:
1. dma_fence_is_signaled_locked() should only be used when holding
   the fence's individual lock, not just the fence list lock
2. Using the locked variant without the proper fence lock could lead
   to double-signaling scenarios:
   - Hardware completion signals the fence
   - Software path also tries to signal the same fence

By using dma_fence_is_signaled() instead, we properly handle the
locking hierarchy and avoid the race condition while still maintaining
the necessary synchronization through the fence_list_lock.

v2: drop the comment (Christian)

Reviewed-by: Christian König 
Signed-off-by: Jesse Zhang 
Signed-off-by: Alex Deucher

drm/amdgpu/userq: add force completion helpers

2025-09-05T21:38:38+00:00

Add support for forcing completion of userq fences.
This is needed for userq resets and asic resets so that we
can set the error on the fence and force completion.

Reviewed-by: Christian König 
Signed-off-by: Alex Deucher

Merge drm/drm-next into drm-misc-next

2025-06-11T07:01:34+00:00

Backmerging to forward to v6.16-rc1

Signed-off-by: Thomas Zimmermann