From nobody Tue Jun 30 05:36:54 2026 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 1233BC433FE for ; Mon, 24 Jan 2022 17:19:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244320AbiAXRTl (ORCPT ); Mon, 24 Jan 2022 12:19:41 -0500 Received: from mta-p6.oit.umn.edu ([134.84.196.206]:60758 "EHLO mta-p6.oit.umn.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241556AbiAXRTj (ORCPT ); Mon, 24 Jan 2022 12:19:39 -0500 Received: from localhost (unknown [127.0.0.1]) by mta-p6.oit.umn.edu (Postfix) with ESMTP id 4JjGty58rnz9vC9D for ; Mon, 24 Jan 2022 17:19:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at umn.edu Received: from mta-p6.oit.umn.edu ([127.0.0.1]) by localhost (mta-p6.oit.umn.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 2wcjm_Vq0nlA for ; Mon, 24 Jan 2022 11:19:38 -0600 (CST) Received: from mail-pf1-f200.google.com (mail-pf1-f200.google.com [209.85.210.200]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mta-p6.oit.umn.edu (Postfix) with ESMTPS id 4JjGty345pz9vC8v for ; Mon, 24 Jan 2022 11:19:38 -0600 (CST) DMARC-Filter: OpenDMARC Filter v1.3.2 mta-p6.oit.umn.edu 4JjGty345pz9vC8v DKIM-Filter: OpenDKIM Filter v2.11.0 mta-p6.oit.umn.edu 4JjGty345pz9vC8v Received: by mail-pf1-f200.google.com with SMTP id y15-20020a056a001c8f00b004c8fad8f162so1816309pfw.14 for ; Mon, 24 Jan 2022 09:19:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=umn.edu; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=N3N6wJzEY0KplvljaHwRHG8hIgjKSfmZz4U+e3o8/n4=; b=kKgtzRoGQXzwgA6FcvxruW7ZL5r1jYaSsrGQeDWqMyjTOcKY2YTMvWotzDugTbVPCL 1rbbjgBabA9JJi7REFGlLi4WS0EynAZLgCmsfjww+3oxjSsrhkJkRfKCGxUOd4GWjY00 dB9ciyd86LzmS+ELkBLhxAqQ4ApQvUXp17GYFwzATQoSENdM3FAxMTfE71z2xc1ikvvC DoDtTcvkBzUqTJBGcKgic4pVVculsdEVmnYJRALs0jlhwHVZT9fl+CMzW0ZDSnSfiF8V oOJlBEYIKlP1PLrm1sSVODqZGv82g3OH8Jnd55uvUsAeTqfcPLjiKQJ2y5FzcLdn29SF iYWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=N3N6wJzEY0KplvljaHwRHG8hIgjKSfmZz4U+e3o8/n4=; b=mBhzLptFwy4JdlSyc+vYBgDYdOzT5vAFNH9hL0mXx7qzaJTKUehVFzS40On4EklDvB zqBwmvILNt5NIDY5pj4aaIq5kprK+J+nwf8Op0qYeABFggiBnMJb9Jbfj27i2rmPd6OJ cM9qNvra+MdbtYiuu4uptxM61O4dJc+W9Ermk2BAyz3ZdMvK4dK7WrBS4H24hwoVQ/la UvjQnAVKs22K5vhT2cWqyckh3RqrBZD6XhA2JQTwUcvDConBP/EUbWwjONuXF9W/ME20 3xi8gsuu9neYPk6xm6saOBBf0ly9x1MNhgyL7Lpmwtn/4+mGnsN/tTyh/YPacWAiVqmZ ntww== X-Gm-Message-State: AOAM533MQrJWVvj4S87Hi5Y6BK7VZn1fHbc5xrKN8vrZoB5JsjHR8Q50 ZWD/ppENcyRtkPfWJbcyBsYZo9WMxWt5uZJGTiQWTnPAUsmOKX7nUA/ZyfJK2sT9qcVV6NG+aRd 0Rz4sF59oFo+0RQm1QFuxghv+rh1c X-Received: by 2002:a63:41c6:: with SMTP id o189mr4269709pga.613.1643044777749; Mon, 24 Jan 2022 09:19:37 -0800 (PST) X-Google-Smtp-Source: ABdhPJyBC7Yc8Jww7/CWdf2GQDqTT+vDsmi1youjQPMHW0084ltnZDJHX/mfaU0N99eHc/nHOQpt8w== X-Received: by 2002:a63:41c6:: with SMTP id o189mr4269697pga.613.1643044777539; Mon, 24 Jan 2022 09:19:37 -0800 (PST) Received: from zqy787-GE5S.lan ([36.4.61.248]) by smtp.gmail.com with ESMTPSA id nv13sm7703946pjb.17.2022.01.24.09.19.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jan 2022 09:19:37 -0800 (PST) From: Zhou Qingyang To: zhou1615@umn.edu Cc: kjlu@umn.edu, Mauro Carvalho Chehab , Hans Verkuil , Tasos Sahanidis , Yang Yingliang , Christophe JAILLET , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] media: saa7134: Fix a NULL pointer dereference in saa7134_initdev() Date: Tue, 25 Jan 2022 01:19:30 +0800 Message-Id: <20220124171931.62174-1-zhou1615@umn.edu> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In saa7134_initdev(), the return value of vdev_init() is assigned to dev->video_dev and there is a dereference of it after that. The return value of vdev_init() will be NULL on the failure allocation, which could lead to NULL pointer dereference. The same as dev->vbi_dev. Fix this bug by adding a NULL check of dev->video_dev and dev->vbi_dev. This bug was found by a static analyzer. Builds with 'make allyesconfig' show no new warnings, and our static analyzer no longer warns about this code. Fixes: a9622391acb ("V4L/DVB (6792): Fix VBI support") Signed-off-by: Zhou Qingyang --- The analysis employs differential checking to identify inconsistent=20 security operations (e.g., checks or kfrees) between two code paths=20 and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs.=20 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. drivers/media/pci/saa7134/saa7134-core.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/media/pci/saa7134/saa7134-core.c b/drivers/media/pci/s= aa7134/saa7134-core.c index 96328b0af164..0de0b00540b6 100644 --- a/drivers/media/pci/saa7134/saa7134-core.c +++ b/drivers/media/pci/saa7134/saa7134-core.c @@ -1202,6 +1202,11 @@ static int saa7134_initdev(struct pci_dev *pci_dev, pr_info("%s: Overlay support disabled.\n", dev->name); =20 dev->video_dev =3D vdev_init(dev,&saa7134_video_template,"video"); + if (!dev->video_dev) { + err =3D -ENOMEM; + goto err_unregister_video; + } + dev->video_dev->ctrl_handler =3D &dev->ctrl_handler; dev->video_dev->lock =3D &dev->lock; dev->video_dev->queue =3D &dev->video_vbq; @@ -1224,6 +1229,11 @@ static int saa7134_initdev(struct pci_dev *pci_dev, dev->name, video_device_node_name(dev->video_dev)); =20 dev->vbi_dev =3D vdev_init(dev, &saa7134_video_template, "vbi"); + if (!dev->vbi_dev) { + err =3D -ENOMEM; + goto err_unregister_video; + } + dev->vbi_dev->ctrl_handler =3D &dev->ctrl_handler; dev->vbi_dev->lock =3D &dev->lock; dev->vbi_dev->queue =3D &dev->vbi_vbq; --=20 2.25.1