This is a note to let you know that I've just added the patch titled drm/i915: Hold onto an explicit ref to i915_vma_work.pinned to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-i915-hold-onto-an-explicit-ref-to-i915_vma_work..patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 933bb75072aac04a8d2c6eb8b870c89e5eebcc84 Author: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Date: Mon Nov 2 16:19:31 2020 +0000 drm/i915: Hold onto an explicit ref to i915_vma_work.pinned [ Upstream commit 537457a979a02a410b555fab289dcb28b588f33b ] Since __vma_release is run by a kworker after the fence has been signaled, it is no longer protected by the active reference on the vma, and so the alias of vw->pinned to vma->obj is also not protected by a reference on the object. Add an explicit reference for vw->pinned so it will always be safe. Found by inspection. Fixes: 54d7195f8c64 ("drm/i915: Unpin vma->obj on early error") Reported-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v5.6+ Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20201102161931.30031-1-chris@xxxxxxxxxxxxxxxxxx (cherry picked from commit bc73e5d33048b7ab5f12b11b5d923700467a8e1d) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index bc64f773dcdb4..034d0a8d24c8c 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -315,8 +315,10 @@ static void __vma_release(struct dma_fence_work *work) { struct i915_vma_work *vw = container_of(work, typeof(*vw), base); - if (vw->pinned) + if (vw->pinned) { __i915_gem_object_unpin_pages(vw->pinned); + i915_gem_object_put(vw->pinned); + } } static const struct dma_fence_work_ops bind_ops = { @@ -430,7 +432,7 @@ int i915_vma_bind(struct i915_vma *vma, if (vma->obj) { __i915_gem_object_pin_pages(vma->obj); - work->pinned = vma->obj; + work->pinned = i915_gem_object_get(vma->obj); } } else { ret = vma->ops->bind_vma(vma->vm, vma, cache_level, bind_flags);