From 45f574d8dfc1d7da5dce587e5061d1022b5ff035 Mon Sep 17 00:00:00 2001 From: Min Li Date: Fri, 26 May 2023 21:01:31 +0800 Subject: [PATCH] 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 Reviewed-by: Andi Shyti Signed-off-by: Inki Dae Signed-off-by: Sasha Levin --- drivers/gpu/drm/exynos/exynos_drm_g2d.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c index fcee33a43aca..2df04de7f435 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);