This is a note to let you know that I've just added the patch titled
drm: mxsfb: Fix NULL pointer dereference
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-mxsfb-fix-null-pointer-dereference.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 16d1845d71f4224988a9cc7b2a6a9e07b0bc3401
Author: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
Date: Wed Feb 2 09:17:55 2022 +0100
drm: mxsfb: Fix NULL pointer dereference
[ Upstream commit 622c9a3a7868e1eeca39c55305ca3ebec4742b64 ]
mxsfb should not ever dereference the NULL pointer which
drm_atomic_get_new_bridge_state is allowed to return.
Assume a fixed format instead.
Fixes: b776b0f00f24 ("drm: mxsfb: Use bus_format from the nearest bridge if present")
Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
Signed-off-by: Marek Vasut <marex@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202081755.145716-3-alexander.stein@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
index b96ba348c68d9..988bc4fbd78df 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
@@ -361,7 +361,11 @@ static void mxsfb_crtc_atomic_enable(struct drm_crtc *crtc,
bridge_state =
drm_atomic_get_new_bridge_state(state,
mxsfb->bridge);
- bus_format = bridge_state->input_bus_cfg.format;
+ if (!bridge_state)
+ bus_format = MEDIA_BUS_FMT_FIXED;
+ else
+ bus_format = bridge_state->input_bus_cfg.format;
+
if (bus_format == MEDIA_BUS_FMT_FIXED) {
dev_warn_once(drm->dev,
"Bridge does not provide bus format, assuming MEDIA_BUS_FMT_RGB888_1X24.\n"
