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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 6045AC4338F for ; Fri, 20 Aug 2021 07:52:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3738361042 for ; Fri, 20 Aug 2021 07:52:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238804AbhHTHxF (ORCPT ); Fri, 20 Aug 2021 03:53:05 -0400 Received: from out30-54.freemail.mail.aliyun.com ([115.124.30.54]:35943 "EHLO out30-54.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236378AbhHTHxA (ORCPT ); Fri, 20 Aug 2021 03:53:00 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R841e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04400;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0UkHjRXA_1629445940; Received: from localhost(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0UkHjRXA_1629445940) by smtp.aliyun-inc.com(127.0.0.1); Fri, 20 Aug 2021 15:52:21 +0800 From: Xianting Tian To: amit@kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Xianting Tian Subject: [RESEND][PATCH] virtio_console: protect max_nr_ports to avoid invalid value Date: Fri, 20 Aug 2021 15:52:19 +0800 Message-Id: <20210820075219.202404-1-xianting.tian@linux.alibaba.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In theory untrusted remote host can pass a big or overflow value of max_nr_ports to guest, it may cause guest system consumes a lot of memory when create vqs and other impacts. Add the protection to guarantee max_nr_ports to get a safe value. Signed-off-by: Xianting Tian --- drivers/char/virtio_console.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 7eaf303a7..bba985c81 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -29,6 +29,8 @@ #define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC) +#define MAX_NR_PORTS MAX_NR_HVC_CONSOLES + /* * This is a global struct for storing common data for all the devices * this driver handles. @@ -2039,6 +2041,9 @@ static int virtcons_probe(struct virtio_device *vdev) multiport = true; } + /* limit max_nr_ports to avoid invalid value from untrusted remote host */ + portdev->max_nr_ports = min_t(u32, portdev->max_nr_ports, MAX_NR_PORTS); + err = init_vqs(portdev); if (err < 0) { dev_err(&vdev->dev, "Error %d initializing vqs\n", err); -- 2.17.1