[PATCH][next] drm/panel: fix null pointer dereference on pointer mode

From: Colin King
Date: Fri Sep 18 2020 - 11:51:50 EST

From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Currently a null pointer check on pointer mode is passing mode to
function drm_mode_vrefresh and this causes a null pointer dereference
on mode. Fix this by not calling drm_mode_vrefresh since the call
is only required for error reporting.

Addresses-Coverity: ("Dereference after null check")
Fixes: 72967d5616d3 ("drm/panel: Add panel driver for the Mantix MLAF057WE51-X DSI panel")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c b/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c
index 3482e28e30fc..be4761a643f9 100644
--- a/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c
+++ b/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c
@@ -202,9 +202,8 @@ static int mantix_get_modes(struct drm_panel *panel,

mode = drm_mode_duplicate(connector->dev, &default_mode);
if (!mode) {
- dev_err(ctx->dev, "Failed to add mode %ux%u@%u\n",
- default_mode.hdisplay, default_mode.vdisplay,
- drm_mode_vrefresh(mode));
+ dev_err(ctx->dev, "Failed to add mode %ux%u\n",
+ default_mode.hdisplay, default_mode.vdisplay);
return -ENOMEM;