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 DFA98C433EF for ; Mon, 24 Jan 2022 18:59:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343648AbiAXS7Y (ORCPT ); Mon, 24 Jan 2022 13:59:24 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:56110 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343495AbiAXS5D (ORCPT ); Mon, 24 Jan 2022 13:57:03 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 3192D61562; Mon, 24 Jan 2022 18:57:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 121A0C36AEC; Mon, 24 Jan 2022 18:57:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643050622; bh=R1Ks1+PCvdgWaCBScyCkSEWthZvRFUjY3tMhIVMKsH0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xWANy4D5zsKryJ41O+4OoiPeu9BnquIToMJk2oxye22RC71HynKzbaY4O68GbmUI6 zTjnEPj1wPOjOTWVGMfVcMkutOGI7ML7Q6Al+B7G7pob/WBDnxMJvGR0NWihvxWPga sx2tnYHUkKOdzLtfaPMxXmCAsxfmLh8qjXYlFZQc= 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 4.9 043/157] media: saa7146: mxb: Fix a NULL pointer dereference in mxb_attach() Date: Mon, 24 Jan 2022 19:42:13 +0100 Message-Id: <20220124183934.162201552@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183932.787526760@linuxfoundation.org> References: <20220124183932.787526760@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: linux-kernel@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 3e8753c9e1e47..849c2a1d09f99 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