From patchwork Mon Feb 24 06:42:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" X-Patchwork-Id: 1242823 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com 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 ozlabs.org (Postfix) with ESMTPS id 48Qswp3Z5nz9sR4 for ; Mon, 24 Feb 2020 17:44:10 +1100 (AEDT) Received: from localhost ([::1]:60530 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j67TM-0000GV-DC for incoming@patchwork.ozlabs.org; Mon, 24 Feb 2020 01:44:08 -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 X-Originating-IP: [10.173.228.124] X-CFilter-Loop: Reflected 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+incoming=patchwork.ozlabs.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) if (!log || log->size != size) { log = vhost_log_alloc(size, share); + if (!log) { + return NULL; + } + if (share) { vhost_log_shm = log; } else { @@ -270,10 +274,17 @@ static bool vhost_dev_log_is_shared(struct vhost_dev *dev) static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) { - struct vhost_log *log = vhost_log_get(size, vhost_dev_log_is_shared(dev)); - uint64_t log_base = (uintptr_t)log->log; + struct vhost_log *log; + uint64_t log_base; int r; + log = vhost_log_get(size, vhost_dev_log_is_shared(dev)); + if (!log) { + return; + } + + log_base = (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 = dev->vhost_ops->vhost_set_log_base(dev, log_base, log); @@ -1640,6 +1651,10 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) hdev->log_size = vhost_get_log_size(hdev); hdev->log = vhost_log_get(hdev->log_size, vhost_dev_log_is_shared(hdev)); + if (!hdev->log) { + goto fail_vq; + } + log_base = (uintptr_t)hdev->log->log; r = hdev->vhost_ops->vhost_set_log_base(hdev, hdev->log_size ? log_base : 0,