[PATCH v2 05/17] drm/v3d: Don't allow two multisync extensions in the same job

[Maíra Canal]

Currently, two multisync extensions can be added to the same job and
only the last multisync extension will be used. To avoid this
vulnerability, don't allow two multisync extensions in the same job.

Signed-off-by: Maíra Canal <mcanal at igalia.com>
---
 drivers/gpu/drm/v3d/v3d_submit.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/v3d/v3d_submit.c b/drivers/gpu/drm/v3d/v3d_submit.c
index e18e7c963884..fe46dd316ca0 100644
--- a/drivers/gpu/drm/v3d/v3d_submit.c
+++ b/drivers/gpu/drm/v3d/v3d_submit.c
@@ -329,6 +329,11 @@ v3d_get_multisync_submit_deps(struct drm_file *file_priv,
 	struct v3d_submit_ext *se = data;
 	int ret;
 
+	if (se->in_sync_count || se->out_sync_count) {
+		DRM_DEBUG("Two multisync extensions were added to the same job.");
+		return -EINVAL;
+	}
+
 	if (copy_from_user(&multisync, ext, sizeof(multisync)))
 		return -EFAULT;
 
-- 
2.41.0