linux-kernel - Re: [PATCH 3/3] drm/bridge: imx8qxp-pixel-combiner: Fix bailout for imx8qxp_pc_bridge

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <42f86084-5200-4dc0-86a7-4719d7d19cf7@nxp.com>
Date: Mon, 26 Jan 2026 16:47:01 +0800
From: Liu Ying <victor.liu@....com>
To: Luca Ceresoli <luca.ceresoli@...tlin.com>,
 Andrzej Hajda <andrzej.hajda@...el.com>,
 Neil Armstrong <neil.armstrong@...aro.org>, Robert Foss <rfoss@...nel.org>,
 Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
 Jonas Karlman <jonas@...boo.se>, Jernej Skrabec <jernej.skrabec@...il.com>,
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>,
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
 Shawn Guo <shawnguo@...nel.org>, Sascha Hauer <s.hauer@...gutronix.de>,
 Pengutronix Kernel Team <kernel@...gutronix.de>,
 Fabio Estevam <festevam@...il.com>
Cc: dri-devel@...ts.freedesktop.org, imx@...ts.linux.dev,
 linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] drm/bridge: imx8qxp-pixel-combiner: Fix bailout for
 imx8qxp_pc_bridge_probe()



On Mon, Jan 26, 2026 at 09:33:38AM +0100, Luca Ceresoli wrote:
> On Fri Jan 23, 2026 at 10:22 AM CET, Liu Ying wrote:
>> In case the channel0 is unavailable and bailing out from free_child is
>> needed when we fail to add a DRM bridge for the available channel1,
>> pointer pc->ch[0] in the bailout path would be NULL and it would be
>> dereferenced as pc->ch[0]->bridge.next_bridge.  Fix this by checking
>> pc->ch[0] before dereferencing it.
> 
> Thanks for checking this code and providing fixes! These drivers have a
> complex code path so I had a hard time in following the logic without neing
> able to test on hardware. Apologies for the issues emerged.

Thanks for your quick review and hard work!

> 
>> Fixes: ae754f049ce1 ("drm/bridge: imx8qxp-pixel-combiner: get/put the next bridge")
>> Fixes: 99764593528f ("drm/bridge: imx8qxp-pixel-combiner: convert to devm_drm_bridge_alloc() API")
> 
> The bug was introduced by 99764593528f, while ae754f049ce1 is not changing
> the bug, so for the sake of precision we can remove the first 'Fixes:'
> line.

I added Fixes tag for ae754f049ce1 because it is the first commit which
this commit could be applied upon properly.  Maybe this helps some tools
apply this commit or maybe tools are smart enough to find ae754f049ce1
automatically?

> 
> With that:
>  Reviewed-by: Luca Ceresoli <luca.ceresoli@...tlin.com>

I hope I can have this R-b.  Please let me know if I need to drop the
Fixes tag for ae754f049ce1.

> 
> --
> Luca Ceresoli, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com/

-- 
Regards,
Liu Ying