This is a note to let you know that I've just added the patch titled
drm/exynos: fix race condition UAF in exynos_g2d_exec_ioctl
to the 5.4-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-exynos-fix-race-condition-uaf-in-exynos_g2d_exec.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6fc8b6e1886a55141c9e6b20b3755da81ea3d3e5
Author: Min Li <lm0963hack@xxxxxxxxx>
Date: Fri May 26 21:01:31 2023 +0800
drm/exynos: fix race condition UAF in exynos_g2d_exec_ioctl
[ Upstream commit 48bfd02569f5db49cc033f259e66d57aa6efc9a3 ]
If it is async, runqueue_node is freed in g2d_runqueue_worker on another
worker thread. So in extreme cases, if g2d_runqueue_worker runs first, and
then executes the following if statement, there will be use-after-free.
Signed-off-by: Min Li <lm0963hack@xxxxxxxxx>
Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
Signed-off-by: Inki Dae <inki.dae@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
index fcee33a43aca3..2df04de7f4354 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
@@ -1332,7 +1332,7 @@ int exynos_g2d_exec_ioctl(struct drm_device *drm_dev, void *data,
/* Let the runqueue know that there is work to do. */
queue_work(g2d->g2d_workq, &g2d->runqueue_work);
- if (runqueue_node->async)
+ if (req->async)
goto out;
wait_for_completion(&runqueue_node->complete);
