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 <[email protected]> Reviewed-by: Andi Shyti <[email protected]> Signed-off-by: Inki Dae <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
arter97 · Jun 28, 2023 · 45f574d · 45f574d
1 parent c81a542
commit 45f574d
Showing 1 changed file with 1 addition and 1 deletion.
diff --git 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);