[PATCH 08/27] drm/amd/display: Validate plane rects before use

[Agustin Gutierrez]

From: Aric Cyr <aric.cyr at amd.com>

[Why]
Calculation of scaling ratio can result in a crash due to zero'd src or
dst plane rects.

[How]
Validate that src and dst rects are valid before using for scaling
calculations.

Reviewed-by: Josip Pavic <Josip.Pavic at amd.com>
Acked-by: Agustin Gutierrez Sanchez <agustin.gutierrez at amd.com>
Signed-off-by: Aric Cyr <aric.cyr at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 561c10a92bb5..9e83fd54e2ca 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -3009,6 +3009,11 @@ enum dc_status dc_validate_plane(struct dc *dc, const struct dc_plane_state *pla
 {
 	enum dc_status res = DC_OK;
 
+	/* check if surface has invalid dimensions */
+	if (plane_state->src_rect.width == 0 || plane_state->src_rect.height == 0 ||
+		plane_state->dst_rect.width == 0 || plane_state->dst_rect.height == 0)
+		return DC_FAIL_SURFACE_VALIDATE;
+
 	/* TODO For now validates pixel format only */
 	if (dc->res_pool->funcs->validate_plane)
 		return dc->res_pool->funcs->validate_plane(plane_state, &dc->caps);
-- 
2.25.1