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@gmail.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Min Li 2023-05-26 21:01:31 +08:00 committed by Greg Kroah-Hartman
parent aa88042218
commit 022f2306d9

View File

@ -1335,7 +1335,7 @@ 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);