From patchwork Mon Jan 24 18:42:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 536222 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 CE582C4332F for ; Mon, 24 Jan 2022 19:23:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349987AbiAXTXA (ORCPT ); Mon, 24 Jan 2022 14:23:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348651AbiAXTTX (ORCPT ); Mon, 24 Jan 2022 14:19:23 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A75CBC02B8CB; Mon, 24 Jan 2022 11:07:37 -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 ams.source.kernel.org (Postfix) with ESMTPS id 1F2CDB81236; Mon, 24 Jan 2022 19:07:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48929C340E5; Mon, 24 Jan 2022 19:07:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643051254; bh=YeXAOZqsXJopt9g24xu3z88wjjco8btdyftcUw/InUg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rXFEViF9KwCrP66jovUtKLBE0mRdnZrCenfYzddrXsQK4Io5GXJWDfEjGznep1zeY PiudWPgFT8j5xyuWXQskCRrF7qujax+75cJnXCzb4xcUpESdW7TFT3XZFdEXKbxWMA 4jPr0eKpNxSMAe6FutvjXlPNq/JG8ispSDIIrHTA= 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 4.14 102/186] media: saa7146: hexium_orion: Fix a NULL pointer dereference in hexium_attach() Date: Mon, 24 Jan 2022 19:42:57 +0100 Message-Id: <20220124183940.395935956@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 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 cb71653a66694..908de2f768441 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;