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 AB097C43217 for ; Tue, 18 Jan 2022 03:35:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346579AbiARDfv (ORCPT ); Mon, 17 Jan 2022 22:35:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376600AbiARDcl (ORCPT ); Mon, 17 Jan 2022 22:32:41 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D3C8C03325A; Mon, 17 Jan 2022 19:08:52 -0800 (PST) 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 AAE1160439; Tue, 18 Jan 2022 03:08:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1406FC36AEF; Tue, 18 Jan 2022 03:08:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642475331; bh=0v+JllOVEUPwx1fjNp5aIjDUrj9rNqlMNdUqUcRfCJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aYn47IZCUSdH3aiBgsmWZX8WI40RUQbGYhh7a5qX2czruIT9YmTQptuSAmWn9WZAE OTdjRhBdnRL1kEd7052c2Du/CEGO6goaSkfb4/FHT22Dc6f9v/PSpud5hxhQLbVpIj u3KGc7PLYHNydg1OUe1QqSGi2Co7c9nCa4fYpb89QmGQ/A+V8qcSM4BJkBOS9WmljH 6kUbEImga6KZoC/R8DQKpS1B6PGpAgrgUYnTouSL7y85DtRRWwfRbIylwZHRlz7tDG QySOKGzIQ4p60TvC2qlJoGs/HuQQiQY+tSIujc9E1PecPmMOdwyFMaxSVD2NgUV4uI l+QgeYHuyg1uA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zhou Qingyang , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin , hverkuil@xs4all.nl, mchehab@kernel.org, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 10/29] media: saa7146: hexium_orion: Fix a NULL pointer dereference in hexium_attach() Date: Mon, 17 Jan 2022 22:08:03 -0500 Message-Id: <20220118030822.1955469-10-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118030822.1955469-1-sashal@kernel.org> References: <20220118030822.1955469-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhou Qingyang [ Upstream commit 348df8035301dd212e3cc2860efe4c86cb0d3303 ] In hexium_attach(dev, info), saa7146_vv_init() is called to allocate a new memory for dev->vv_data. In hexium_detach(), saa7146_vv_release() will be called and 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() according to the following logic. Both hexium_attach() and hexium_detach() are callback functions of the variable 'extension', so there exists a possible call chain directly from hexium_attach() to hexium_detach(): hexium_attach(dev, info) -- fail to alloc memory to dev->vv_data | in saa7146_vv_init(). | | hexium_detach() -- a dereference of dev->vv_data in saa7146_vv_release() 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_HEXIUM_ORION=m show no new warnings, and our static analyzer no longer warns about this code. 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/hexium_orion.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/media/pci/saa7146/hexium_orion.c b/drivers/media/pci/saa7146/hexium_orion.c index 214396b1ca73c..2f3b4e01ff289 100644 --- a/drivers/media/pci/saa7146/hexium_orion.c +++ b/drivers/media/pci/saa7146/hexium_orion.c @@ -366,10 +366,16 @@ static struct saa7146_ext_vv vv_data; static int hexium_attach(struct saa7146_dev *dev, struct saa7146_pci_extension_data *info) { struct hexium *hexium = (struct hexium *) dev->ext_priv; + int ret; DEB_EE("\n"); - saa7146_vv_init(dev, &vv_data); + ret = saa7146_vv_init(dev, &vv_data); + if (ret) { + pr_err("Error in saa7146_vv_init()\n"); + return ret; + } + vv_data.vid_ops.vidioc_enum_input = vidioc_enum_input; vv_data.vid_ops.vidioc_g_input = vidioc_g_input; vv_data.vid_ops.vidioc_s_input = vidioc_s_input; -- 2.34.1