diff --git a/sys/dev/drm/radeon/radeon_vce.c b/sys/dev/drm/radeon/radeon_vce.c
--- a/sys/dev/drm/radeon/radeon_vce.c
+++ b/sys/dev/drm/radeon/radeon_vce.c
@@ -94,6 +94,8 @@
 
 	/* search for firmware version */
 
+	if (rdev->vce_fw->datasize < strlen(fw_version) + 9)
+		return -EINVAL;
 	size = rdev->vce_fw->datasize - strlen(fw_version) - 9;
 	c = rdev->vce_fw->data;
 	for (;size > 0; --size, ++c)