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=-17.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 13E48C4707F for ; Tue, 25 May 2021 06:23:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2C0561413 for ; Tue, 25 May 2021 06:23:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230426AbhEYGZB (ORCPT ); Tue, 25 May 2021 02:25:01 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:23256 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230493AbhEYGY4 (ORCPT ); Tue, 25 May 2021 02:24:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621923806; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RqC+rL03NFU00q36iPYaCWY4fHiegTpGAwzrspkzWwU=; b=GVug03hw1sZcb9Wb+KKL7CaHuWURywZ7gSiHNqvXivsvx7JruHqaDQqOttK1EC9uJ28xW5 2PiQxBd39E7LDxG7ZSuFok8pmruTrmPPhsAEEqCbVo32+rlIOCQy3l6lHCCx0WUtlPjAId yBreBL3kYCwm6k2cbIBaIUWrqSiM9a0= Received: from mail-pl1-f198.google.com (mail-pl1-f198.google.com [209.85.214.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-585-SEosPU_sOp2W7li400SkPw-1; Tue, 25 May 2021 02:23:25 -0400 X-MC-Unique: SEosPU_sOp2W7li400SkPw-1 Received: by mail-pl1-f198.google.com with SMTP id m12-20020a170902f20cb02900ef9c8577c4so14222472plc.19 for ; Mon, 24 May 2021 23:23:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=RqC+rL03NFU00q36iPYaCWY4fHiegTpGAwzrspkzWwU=; b=rxXLNPPP+wbx5hkLPPvreUqEHS3okAAHPGg8EDSzwpLsmhmXpo+RggoslnEbYVhMkg zBAhYI3ZIuIPOFkaMfn8A8WnMtXtbAAnXArsPWxdJBoBxnt7W61wSkoMBWNUTRjWn75C xH+MCsAKfn/s0i8848L8oKYql9whwJSgmUtleS1fqqx0ABgxq7hFcNyP5oJ6fYF+SpvP tTv7K7MMw4P78SLG+CJVuMbfL3e8gUi39Cq2r7aL+WHiZZont0c5MW/WC4SR4ZLg7mWN YMTnE/b8zOe7DsNgMY5oYHQ70T+xVPz6w1i5F7lV1xkvNyjxv3Ob3hsR96yXTGiW4rIJ k86g== X-Gm-Message-State: AOAM533f1LoePDHScLXkObcpp9Wquom+7ULnkKv5PdRHkOW1w+E8rzcG te6KKijpI8iXvHok+x8rCGFfoIj3IqdX302yOHR6of4l94wMzV1mY+Mo86ZnEeYqmMP8GzRpgQN QLv6XQlsnl9MoNKjgiEMo1aYECnIRmkqhifsHrp+VfJeX872rATeDtEbGSwA7IoQ7puK6BPbSwR EY X-Received: by 2002:a17:90a:602:: with SMTP id j2mr29435214pjj.211.1621923803929; Mon, 24 May 2021 23:23:23 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzthPvWzWsy+OgjCaqNyzQJxLtpWU/5mo8q3NP6jddpWWmCJIfZD4jC3PimfRJ+ctmhjllivg== X-Received: by 2002:a17:90a:602:: with SMTP id j2mr29435186pjj.211.1621923803627; Mon, 24 May 2021 23:23:23 -0700 (PDT) Received: from wangxiaodeMacBook-Air.local ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id j20sm10584356pfj.40.2021.05.24.23.23.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 24 May 2021 23:23:23 -0700 (PDT) Subject: Re: [PATCH] virtio_console: Assure used length from device is limited To: Xie Yongji , amit@kernel.org, mst@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20210525045304.1085-1-xieyongji@bytedance.com> From: Jason Wang Message-ID: <007b4e26-8ea1-ac22-fd77-e54b7417351b@redhat.com> Date: Tue, 25 May 2021 14:23:19 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: <20210525045304.1085-1-xieyongji@bytedance.com> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ÔÚ 2021/5/25 ÏÂÎç12:53, Xie Yongji дµÀ: > The buf->len might come from an untrusted device. This > ensures the value would not exceed the size of the buffer > to avoid data corruption or loss. > > Signed-off-by: Xie Yongji Acked-by: Jason Wang > --- > drivers/char/virtio_console.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > index 1c40ca6d76ba..598863e6daf8 100644 > --- a/drivers/char/virtio_console.c > +++ b/drivers/char/virtio_console.c > @@ -475,7 +475,7 @@ static struct port_buffer *get_inbuf(struct port *port) > > buf = virtqueue_get_buf(port->in_vq, &len); > if (buf) { > - buf->len = len; > + buf->len = min(len, buf->size); > buf->offset = 0; > port->stats.bytes_received += len; > } > @@ -1709,7 +1709,7 @@ static void control_work_handler(struct work_struct *work) > while ((buf = virtqueue_get_buf(vq, &len))) { > spin_unlock(&portdev->c_ivq_lock); > > - buf->len = len; > + buf->len = min(len, buf->size); > buf->offset = 0; > > handle_control_message(vq->vdev, portdev, buf);