From 7c703a7d3f2b50a6187267420a4d3d7e62fa3206 Mon Sep 17 00:00:00 2001 From: xinhui pan Date: Tue, 12 Apr 2022 19:52:16 +0800 Subject: drm/amdgpu: Fix one use-after-free of VM MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit VM might already be freed when amdgpu_vm_tlb_seq_cb() is called. We see the calltrace below. Fix it by keeping the last flush fence around and wait for it to signal BUG kmalloc-4k (Not tainted): Poison overwritten 0xffff9c88630414e8-0xffff9c88630414e8 @offset=5352. First byte 0x6c instead of 0x6b Allocated in amdgpu_driver_open_kms+0x9d/0x360 [amdgpu] age=44 cpu=0 pid=2343 __slab_alloc.isra.0+0x4f/0x90 kmem_cache_alloc_trace+0x6b8/0x7a0 amdgpu_driver_open_kms+0x9d/0x360 [amdgpu] drm_file_alloc+0x222/0x3e0 [drm] drm_open+0x11d/0x410 [drm] Freed in amdgpu_driver_postclose_kms+0x3e9/0x550 [amdgpu] age=22 cpu=1 pid=2485 kfree+0x4a2/0x580 amdgpu_driver_postclose_kms+0x3e9/0x550 [amdgpu] drm_file_free+0x24e/0x3c0 [drm] drm_close_helper.isra.0+0x90/0xb0 [drm] drm_release+0x97/0x1a0 [drm] __fput+0xb6/0x280 ____fput+0xe/0x10 task_work_run+0x64/0xb0 Suggested-by: Christian König Signed-off-by: xinhui pan Reviewed-by: Christian König Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h') diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h index 1a814fbffff8..6b06a214f05f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h @@ -286,6 +286,7 @@ struct amdgpu_vm { /* Last finished delayed update */ atomic64_t tlb_seq; + struct dma_fence *last_tlb_flush; /* Last unlocked submission to the scheduler entities */ struct dma_fence *last_unlocked; -- cgit v1.2.3