From b2dcb8edf64109bdd72ea03afdc5dcc9933f783d Mon Sep 17 00:00:00 2001
From: Aric Cyr <aric.cyr@amd.com>
Date: Tue, 28 Sep 2021 16:05:27 -0400
Subject: drm/amd/display: Validate plane rects before use
Git-commit: 94e587b8d1bbfb9fbce5b158c2b63d1af6a73af1
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

[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@amd.com>
Acked-by: Agustin Gutierrez Sanchez <agustin.gutierrez@amd.com>
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 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);
-- 
2.38.1