From: Srinivasan Shanmugam Date: Wed, 14 Jan 2026 10:44:53 +0000 (+0530) Subject: drm/amdgpu/userq: Fix fence reference leak on queue teardown v2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b2426a211dba6432e32a2e70e9183c6e134475c6;p=thirdparty%2Flinux.git drm/amdgpu/userq: Fix fence reference leak on queue teardown v2 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) --- diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c index 53d8707f9881..85e9edc1cb6f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c @@ -141,6 +141,8 @@ static void amdgpu_userq_walk_and_drop_fence_drv(struct xarray *xa) void amdgpu_userq_fence_driver_free(struct amdgpu_usermode_queue *userq) { + dma_fence_put(userq->last_fence); + amdgpu_userq_walk_and_drop_fence_drv(&userq->fence_drv_xa); xa_destroy(&userq->fence_drv_xa); /* Drop the fence_drv reference held by user queue */