From: Min Li Date: Fri, 26 May 2023 13:01:31 +0000 (+0800) Subject: drm/exynos: fix race condition UAF in exynos_g2d_exec_ioctl X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=48bfd02569f5db49cc033f259e66d57aa6efc9a3;p=linux.git drm/exynos: fix race condition UAF in exynos_g2d_exec_ioctl 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 --- diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c index ec784e58da5c1..414e585ec7dd0 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c +++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c @@ -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);