Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Alexander Stein <alexander.stein@ew.tq-group.com>
To: Marek Vasut <marex@denx.de>, Stefan Agner <stefan@agner.ch>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>
Cc: Alexander Stein <alexander.stein@ew.tq-group.com>,
	linux-arm-kernel@lists.infradead.org,
	dri-devel@lists.freedesktop.org
Subject: [PATCH 1/1] drm: mxsfb: Fix NULL pointer dereference
Date: Fri, 21 Jan 2022 14:12:38 +0100	[thread overview]
Message-ID: <20220121131238.507567-1-alexander.stein@ew.tq-group.com> (raw)

Do not deference the NULL pointer if the bridge does not return a
bridge state. Assume a fixed format instead.

Fixes: commit b776b0f00f24 ("drm: mxsfb: Use bus_format from the nearest bridge if present")
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
---
This can happen if a "ti,sn75lvds83", "lvds-encoder" bridge is attached
to it. atomic_get_input_bus_fmts is only implemented for the
lvds-decoder case.

 drivers/gpu/drm/mxsfb/mxsfb_kms.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
index 0655582ae8ed..4cfb6c001679 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"
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2022-01-21 13:14 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-21 13:12 Alexander Stein [this message]
2022-01-21 13:14 ` [PATCH 1/1] drm: mxsfb: Fix NULL pointer dereference Marek Vasut
2022-01-21 13:24   ` (EXT) " Alexander Stein
2022-01-21 13:28     ` Marek Vasut

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220121131238.507567-1-alexander.stein@ew.tq-group.com \
    --to=alexander.stein@ew.tq-group.com \
    --cc=airlied@linux.ie \
    --cc=daniel@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=festevam@gmail.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=marex@denx.de \
    --cc=s.hauer@pengutronix.de \
    --cc=shawnguo@kernel.org \
    --cc=stefan@agner.ch \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox