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"