From patchwork Thu Feb 2 06:27:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zheng Wang X-Patchwork-Id: 13125410 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 BDF64C05027 for ; Thu, 2 Feb 2023 06:44:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230054AbjBBGo1 (ORCPT ); Thu, 2 Feb 2023 01:44:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229609AbjBBGoZ (ORCPT ); Thu, 2 Feb 2023 01:44:25 -0500 Received: from m12.mail.163.com (m12.mail.163.com [220.181.12.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 16B7D79C9B; Wed, 1 Feb 2023 22:44:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=6hzHM L8zJZo5EjDWZpassjEzpK+oxlFSmZP2G2l+x5s=; b=V/oxsXM0Iqsc6Q01CvuNZ HZiDqNC1VadNjuJ3haAV5r/WLZlxZlw8lUr13A4UaldYeVRvZcpXF/ImXKJwIHBN M0G+5LMQPuXh7M+2IKFqrPd640PpMS2ibVLWwHsBMyyMWcwvkQ0Z0htRAR2XaV8C N27qJhsoapquVDEwywWKJo= Received: from leanderwang-LC2.localdomain (unknown [111.206.145.21]) by zwqz-smtp-mta-g4-0 (Coremail) with SMTP id _____wB3ePTuV9tjNPomCg--.47862S2; Thu, 02 Feb 2023 14:27:58 +0800 (CST) From: Zheng Wang To: mst@redhat.com Cc: jasowang@redhat.com, pbonzini@redhat.com, stefanha@redhat.com, jejb@linux.ibm.com, martin.petersen@oracle.com, virtualization@lists.linux-foundation.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, security@kernel.org, alex000young@gmail.com, Zheng Wang Subject: [PATCH] scsi: virtio_scsi: Fix poential NULL pointer dereference in virtscsi_rescan_hotunplug Date: Thu, 2 Feb 2023 14:27:56 +0800 Message-Id: <20230202062756.21130-1-zyytlz.wz@163.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CM-TRANSID: _____wB3ePTuV9tjNPomCg--.47862S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7KFy5Cry8CrW7Gw4rGw1UGFg_yoW8ZF4kpr WYy34jyw45Ga1xWayFgFZxCw1Y9ws7Wry7tayYg3y5WF45WryIqa1DJ34UZFW5XF95J3Z8 Aa10gF1j9ryDuFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0pEL0eDUUUUU= X-Originating-IP: [111.206.145.21] X-CM-SenderInfo: h2113zf2oz6qqrwthudrp/xtbBugQKU1+GuBlNgQAAsT Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org There is no check about the return value of kmalloc in virtscsi_rescan_hotunplug. Add the check to avoid use of null pointer 'inq_result' in case of the failure of kmalloc. Signed-off-by: Zheng Wang --- drivers/scsi/virtio_scsi.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c index d07d24c06b54..f198e281b1d3 100644 --- a/drivers/scsi/virtio_scsi.c +++ b/drivers/scsi/virtio_scsi.c @@ -330,13 +330,16 @@ static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, scsi_device_put(sdev); } -static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) +static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) { struct scsi_device *sdev; struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); unsigned char scsi_cmd[MAX_COMMAND_SIZE]; int result, inquiry_len, inq_result_len = 256; char *inq_result = kmalloc(inq_result_len, GFP_KERNEL); + + if (!inq_result) + return -ENOMEM; shost_for_each_device(sdev, shost) { inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; @@ -366,6 +369,7 @@ static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) } kfree(inq_result); + return 0; } static void virtscsi_handle_event(struct work_struct *work) @@ -374,12 +378,15 @@ static void virtscsi_handle_event(struct work_struct *work) container_of(work, struct virtio_scsi_event_node, work); struct virtio_scsi *vscsi = event_node->vscsi; struct virtio_scsi_event *event = &event_node->event; + int ret = 0; if (event->event & cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { event->event &= ~cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED); - virtscsi_rescan_hotunplug(vscsi); + ret = virtscsi_rescan_hotunplug(vscsi); + if (ret) + return; scsi_scan_host(virtio_scsi_host(vscsi->vdev)); }