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 852F9C43217 for ; Mon, 24 Jan 2022 19:07:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344196AbiAXTHC (ORCPT ); Mon, 24 Jan 2022 14:07:02 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:59458 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345951AbiAXTEu (ORCPT ); Mon, 24 Jan 2022 14:04:50 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 60203B81232; Mon, 24 Jan 2022 19:04:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A845C340E7; Mon, 24 Jan 2022 19:04:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643051088; bh=3xsSGFKg9Nzum/KgrP/Wsk5RPSyVVIwNmQfiwDbiDo4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dsfE9FmWthzZBjLcdKmzEzAO2loL/1sx6WxpmslGbg7h0564X0rgrCLk5SMn8R19L W74tkuwMDRKDScm95jGKe6bjn9fOB+q7+PtR7FczvLefjYY4Rn3P0uYysMPnKwO9ec rH8W8Tm3GhFDhgs13Y9yp0OKQRUN+T0qO/RlgmLc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhou Qingyang , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 4.14 051/186] media: saa7146: mxb: Fix a NULL pointer dereference in mxb_attach() Date: Mon, 24 Jan 2022 19:42:06 +0100 Message-Id: <20220124183938.771684024@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183937.101330125@linuxfoundation.org> References: <20220124183937.101330125@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhou Qingyang [ Upstream commit 0407c49ebe330333478440157c640fffd986f41b ] In mxb_attach(dev, info), saa7146_vv_init() is called to allocate a new memory for dev->vv_data. saa7146_vv_release() will be called on failure of mxb_probe(dev). There is a dereference of dev->vv_data in saa7146_vv_release(), which could lead to a NULL pointer dereference on failure of saa7146_vv_init(). Fix this bug by adding a check of saa7146_vv_init(). This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_VIDEO_MXB=m show no new warnings, and our static analyzer no longer warns about this code. Fixes: 03b1930efd3c ("V4L/DVB: saa7146: fix regression of the av7110/budget-av driver") Signed-off-by: Zhou Qingyang Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/pci/saa7146/mxb.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/media/pci/saa7146/mxb.c b/drivers/media/pci/saa7146/mxb.c index 2e7bd82282caa..b2260deab94cc 100644 --- a/drivers/media/pci/saa7146/mxb.c +++ b/drivers/media/pci/saa7146/mxb.c @@ -694,10 +694,16 @@ static struct saa7146_ext_vv vv_data; static int mxb_attach(struct saa7146_dev *dev, struct saa7146_pci_extension_data *info) { struct mxb *mxb; + int ret; DEB_EE("dev:%p\n", dev); - saa7146_vv_init(dev, &vv_data); + ret = saa7146_vv_init(dev, &vv_data); + if (ret) { + ERR("Error in saa7146_vv_init()"); + return ret; + } + if (mxb_probe(dev)) { saa7146_vv_release(dev); return -1; -- 2.34.1