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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB14CC3567B for ; Mon, 24 Feb 2020 06:44:30 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8EE9520714 for ; Mon, 24 Feb 2020 06:44:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8EE9520714 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:60544 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j67Th-00016w-PB for qemu-devel@archiver.kernel.org; Mon, 24 Feb 2020 01:44:29 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:47383) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j67S9-000792-WB for qemu-devel@nongnu.org; Mon, 24 Feb 2020 01:42:54 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j67S9-0008WJ-1h for qemu-devel@nongnu.org; Mon, 24 Feb 2020 01:42:53 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:56942 helo=huawei.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j67S8-0008V1-MF for qemu-devel@nongnu.org; Mon, 24 Feb 2020 01:42:52 -0500 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 836BE7125658CEED0852; Mon, 24 Feb 2020 14:42:50 +0800 (CST) Received: from DESKTOP-27KDQMV.china.huawei.com (10.173.228.124) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.439.0; Mon, 24 Feb 2020 14:42:43 +0800 From: "Longpeng(Mike)" To: , Subject: [PATCH RESEND 2/3] vhost: fix a null pointer reference of vhost_log Date: Mon, 24 Feb 2020 14:42:18 +0800 Message-ID: <20200224064219.1434-3-longpeng2@huawei.com> X-Mailer: git-send-email 2.25.0.windows.1 In-Reply-To: <20200224064219.1434-1-longpeng2@huawei.com> References: <20200224064219.1434-1-longpeng2@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.173.228.124] X-CFilter-Loop: Reflected Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 45.249.212.35 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: longpeng2@huawei.com, arei.gonglei@huawei.com, huangzhichao@huawei.com, qemu-devel@nongnu.org, weifuqiang@huawei.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Longpeng vhost_log_alloc() may fails and returned pointer of log is null. However there're two places derefernce the return pointer without check. Signed-off-by: Longpeng --- hw/virtio/vhost.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 9edfadc..c7ad6e5 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -219,6 +219,10 @@ static struct vhost_log *vhost_log_get(uint64_t size= , bool share) =20 if (!log || log->size !=3D size) { log =3D vhost_log_alloc(size, share); + if (!log) { + return NULL; + } + if (share) { vhost_log_shm =3D log; } else { @@ -270,10 +274,17 @@ static bool vhost_dev_log_is_shared(struct vhost_de= v *dev) =20 static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t = size) { - struct vhost_log *log =3D vhost_log_get(size, vhost_dev_log_is_share= d(dev)); - uint64_t log_base =3D (uintptr_t)log->log; + struct vhost_log *log; + uint64_t log_base; int r; =20 + log =3D vhost_log_get(size, vhost_dev_log_is_shared(dev)); + if (!log) { + return; + } + + log_base =3D (uintptr_t)log->log; + /* inform backend of log switching, this must be done before releasing the current log, to ensure no logging is lost */ r =3D dev->vhost_ops->vhost_set_log_base(dev, log_base, log); @@ -1640,6 +1651,10 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIO= Device *vdev) hdev->log_size =3D vhost_get_log_size(hdev); hdev->log =3D vhost_log_get(hdev->log_size, vhost_dev_log_is_shared(hdev)); + if (!hdev->log) { + goto fail_vq; + } + log_base =3D (uintptr_t)hdev->log->log; r =3D hdev->vhost_ops->vhost_set_log_base(hdev, hdev->log_size ? log_bas= e : 0, --=20 1.8.3.1