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 0BE0CC35268 for ; Tue, 18 Jan 2022 03:16:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350270AbiARDQN (ORCPT ); Mon, 17 Jan 2022 22:16:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347952AbiARC5a (ORCPT ); Mon, 17 Jan 2022 21:57:30 -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 79E7BC06135C; Mon, 17 Jan 2022 18:45:28 -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 5B9D161302; Tue, 18 Jan 2022 02:45:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB61CC36AE3; Tue, 18 Jan 2022 02:45:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642473927; bh=stwyFcwrHvk0WqGjAaEa8Do+lR1jsqKuLO+DyPAgQIg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qAvD7WOYQU31tvGgbqwcYSzZ0eEg9wSKypZz4T5eiPvuMojtJmMI6vqXuVFHl6qs5 II22bXoUlHFN9LtKDR0IOpPRuDA5Oa2b6bwb7lFjwRft+FRIOtzNNnopeB3BGoMhM2 w6YOLfaeL9Gl2cqFtxT6RfE6pzJ3gmmYfowJVZxZaKxle4+IHvzPpJVM71l7u8DuWA +ZVnln0N+2XF2r1h5+fOaAMJrJKFI943ydqAzQdRHs7ieA3FJd5jbuiG2ozxLjm/HL FbUC3yUa0sQU6WZGyUtC0tKo09xBUPJlPvl5QcWdhuCq0oD9qAfta3k6CId9ilQ7fn wJAckMZ/QARqg== 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 5.4 26/73] media: saa7146: hexium_orion: Fix a NULL pointer dereference in hexium_attach() Date: Mon, 17 Jan 2022 21:43:45 -0500 Message-Id: <20220118024432.1952028-26-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118024432.1952028-1-sashal@kernel.org> References: <20220118024432.1952028-1-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: linux-kernel@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 bf5e55348f159..31388597386aa 100644 --- a/drivers/media/pci/saa7146/hexium_orion.c +++ b/drivers/media/pci/saa7146/hexium_orion.c @@ -355,10 +355,16 @@ 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