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=-20.2 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,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 77981C63793 for ; Mon, 19 Jul 2021 15:30:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6448760241 for ; Mon, 19 Jul 2021 15:30:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344200AbhGSOsl (ORCPT ); Mon, 19 Jul 2021 10:48:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:48000 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243736AbhGSOdB (ORCPT ); Mon, 19 Jul 2021 10:33:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 14B6E6113E; Mon, 19 Jul 2021 15:13:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626707584; bh=SpbH99waIHWnRMoF0oYxp765ixe9wOOqLld2vMvrrgo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fNcrlRblhLxEhPmc/UMnP9ZGnVaN2fzhvZWPqhlaDtUm6E9F3R74AMAGBsvxovAGH A6gh20N3yhbUJZO2cn5M/8u9m6RR2vyLQRcmD4oGiwMbKRWZfr+LoBMzYtKRUkQFhc KbtRg1cHtdLVdf69OOKjQX+tzNMPbkuwELX8PId4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xie Yongji , Jason Wang , "Michael S. Tsirkin" , Sasha Levin Subject: [PATCH 4.9 223/245] virtio_console: Assure used length from device is limited Date: Mon, 19 Jul 2021 16:52:45 +0200 Message-Id: <20210719144947.594621449@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144940.288257948@linuxfoundation.org> References: <20210719144940.288257948@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xie Yongji [ Upstream commit d00d8da5869a2608e97cfede094dfc5e11462a46 ] 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 Link: https://lore.kernel.org/r/20210525125622.1203-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin --- 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 4ec08c7a7b65..2632b0fdb1b5 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -492,7 +492,7 @@ 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_t(size_t, len, buf->size); buf->offset = 0; port->stats.bytes_received += len; } @@ -1758,7 +1758,7 @@ 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_t(size_t, len, buf->size); buf->offset = 0; handle_control_message(vq->vdev, portdev, buf); -- 2.30.2