From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00CB0C83F12 for ; Mon, 28 Aug 2023 17:28:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232357AbjH1R2a (ORCPT ); Mon, 28 Aug 2023 13:28:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232859AbjH1R2R (ORCPT ); Mon, 28 Aug 2023 13:28:17 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3984012A for ; Mon, 28 Aug 2023 10:28:15 -0700 (PDT) Received: from pendragon.ideasonboard.com (117.145-247-81.adsl-dyn.isp.belgacom.be [81.247.145.117]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 8EF175AA; Mon, 28 Aug 2023 19:26:52 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1693243612; bh=eJNgE5A2Oc+9HepIe/SpnMELLL/klKBosOpPUS0JGNQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j5wqfKislpr+uUXmhUgG/zFj+1evrnIt2E54qcPYPhXFYYyNxpd1eR3UbVvd325Ab ofJMbso5w/WwdRX20NwtygidpX44Pv2TkqPym+vbda1IaniriWZt7aTQPe0lyn23xC e1zevjRQw8hiWufyUsPvL6PeEY+MmZw/opni4d30= Date: Mon, 28 Aug 2023 20:28:22 +0300 From: Laurent Pinchart To: Zhang Shurong Cc: victor.liu@nxp.com, andrzej.hajda@intel.com, neil.armstrong@linaro.org, rfoss@kernel.org, jonas@kwiboo.se, jernej.skrabec@gmail.com, airlied@gmail.com, daniel@ffwll.ch, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/bridge: imx: fix potential NULL pointer dereference in imx8qxp_ldb_parse_dt_companion() Message-ID: <20230828172822.GE14596@pendragon.ideasonboard.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Zhang, Thank you for the patch. On Tue, Aug 29, 2023 at 12:55:01AM +0800, Zhang Shurong wrote: > of_match_device() may fail and returns a NULL pointer. How can it return a NULL pointer here ? > Fix this by checking the return value of of_match_device(). > > Fixes: 3818715f62b4 ("drm/bridge: imx: Add LDB support for i.MX8qxp") > Signed-off-by: Zhang Shurong > --- > drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > index 7984da9c0a35..d272f35c8eac 100644 > --- a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c > @@ -488,6 +488,8 @@ static int imx8qxp_ldb_parse_dt_companion(struct imx8qxp_ldb *imx8qxp_ldb) > * string. > */ > match = of_match_device(dev->driver->of_match_table, dev); > + if (!match) > + return -ENODEV; > if (!of_device_is_compatible(companion, match->compatible)) { > DRM_DEV_ERROR(dev, "companion LDB is incompatible\n"); > ret = -ENXIO; -- Regards, Laurent Pinchart