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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,URIBL_BLOCKED,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 9754DC11F69 for ; Sat, 10 Jul 2021 23:55:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7AF8361057 for ; Sat, 10 Jul 2021 23:55:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232527AbhGJX6k (ORCPT ); Sat, 10 Jul 2021 19:58:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:41020 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233014AbhGJX5j (ORCPT ); Sat, 10 Jul 2021 19:57:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4945961422; Sat, 10 Jul 2021 23:52:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625961160; bh=aPhoA6wAfhnZudDGAdxrZd7Up25mGNliT/992tTLk04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DHKeyeF5NoijI27ZtiaLGZjuMC9g7m+aNscikZyH/tBLtDJW62e2F6QnWuplPQ+sd Ic1PqowICxNpZ6/DRbGfEsFcmim/HXG6PAY1/S9RCrZ08ntgQ0ukxQ9OaXnU4oQaxZ kaJ7ty0oOQ+j2Gn0yOZE4hCuIiKN1r8FDBVcZh8tIIUUx71pakdv2aszVPgAMulUXh lMQl6gAych+qjnGBv7J3w2bc6W8jXmM8+eZ9W59zsKxVOqrocLJEv737uMkp1T5c1o RUUk+1Q4FQz4e/+gksS6gBXkBFIsBq7bDy9/XmcOVa6NftIvI7VXTc4eoayjJ8fNzh hkyklWkjEtthQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xie Yongji , Jason Wang , "Michael S . Tsirkin" , Sasha Levin , virtualization@lists.linux-foundation.org Subject: [PATCH AUTOSEL 4.14 21/21] virtio_console: Assure used length from device is limited Date: Sat, 10 Jul 2021 19:52:12 -0400 Message-Id: <20210710235212.3222375-21-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210710235212.3222375-1-sashal@kernel.org> References: <20210710235212.3222375-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 6a57237e46db..0fb3a8e62e62 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -489,7 +489,7 @@ 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; } @@ -1755,7 +1755,7 @@ 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