[PATCH 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 b6be34060d4f..2c39e2acf01b 100644
--- a/drivers/gpu/drm/v3d/v3d_submit.c
+++ b/drivers/gpu/drm/v3d/v3d_submit.c
@@ -328,6 +328,11 @@ 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