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=-11.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 5C083C2D0DB for ; Wed, 22 Jan 2020 08:52:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3167724672 for ; Wed, 22 Jan 2020 08:52:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579683125; bh=tz88uHDTq37xuuEtDOior9mxQz5a3/bwfDfgrqVQ/sI=; h=Subject:To:From:Date:List-ID:From; b=AR5QWwqGdTO4j5jsNl5449+efznACSJUiF4NLdRCo+mjDAC2j50hl6H58iiFQEY/+ tzUdMg5dxRKxQkwYcFa4dAhJml60wBvC5cBGhKqGq/XQWKf5dr0R6ZbPjbB6mNwsgF PctZ3zWn7LRk7PrZxfluWRe6CmJ2f1ivugBPhOdA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726026AbgAVIwE (ORCPT ); Wed, 22 Jan 2020 03:52:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:47916 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726004AbgAVIwE (ORCPT ); Wed, 22 Jan 2020 03:52:04 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3936C2253D; Wed, 22 Jan 2020 08:52:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579683123; bh=tz88uHDTq37xuuEtDOior9mxQz5a3/bwfDfgrqVQ/sI=; h=Subject:To:From:Date:From; b=KMDh/d/Lfs4MF76LKw0K72RyF8fLUxTcUw6aI2vRb+/NzeXoFDURvTNQzR5h8mWNL W4HMBMQoLmkJrZ5/hFrM0G56+koU61voqD3fz/6l5YPFuioN+WeXUVUnAVEPCzbTTN zQkSyeTgO+vTHhAAktGx6y6ObP9464/EmVpYFkqw= Subject: patch "staging: most: net: fix buffer overflow" added to staging-testing To: andrey.shvetsov@k2l.de, gregkh@linuxfoundation.org, stable@vger.kernel.org From: Date: Wed, 22 Jan 2020 09:52:01 +0100 Message-ID: <157968312110879@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled staging: most: net: fix buffer overflow to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the staging-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From 4d1356ac12f4d5180d0df345d85ff0ee42b89c72 Mon Sep 17 00:00:00 2001 From: Andrey Shvetsov Date: Thu, 16 Jan 2020 18:22:39 +0100 Subject: staging: most: net: fix buffer overflow If the length of the socket buffer is 0xFFFFFFFF (max size for an unsigned int), then payload_len becomes 0xFFFFFFF1 after subtracting 14 (ETH_HLEN). Then, mdp_len is set to payload_len + 16 (MDP_HDR_LEN) which overflows and results in a value of 2. These values for payload_len and mdp_len will pass current buffer size checks. This patch checks if derived from skb->len sum may overflow. The check is based on the following idea: For any `unsigned V1, V2` and derived `unsigned SUM = V1 + V2`, `V1 + V2` overflows iif `SUM < V1`. Reported-by: Greg Kroah-Hartman Signed-off-by: Andrey Shvetsov Cc: stable Link: https://lore.kernel.org/r/20200116172238.6046-1-andrey.shvetsov@microchip.com Signed-off-by: Greg Kroah-Hartman --- drivers/staging/most/net/net.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/staging/most/net/net.c b/drivers/staging/most/net/net.c index 8218c9a06cb5..5547e36e09de 100644 --- a/drivers/staging/most/net/net.c +++ b/drivers/staging/most/net/net.c @@ -82,6 +82,11 @@ static int skb_to_mamac(const struct sk_buff *skb, struct mbo *mbo) unsigned int payload_len = skb->len - ETH_HLEN; unsigned int mdp_len = payload_len + MDP_HDR_LEN; + if (mdp_len < skb->len) { + pr_err("drop: too large packet! (%u)\n", skb->len); + return -EINVAL; + } + if (mbo->buffer_length < mdp_len) { pr_err("drop: too small buffer! (%d for %d)\n", mbo->buffer_length, mdp_len); @@ -129,6 +134,11 @@ static int skb_to_mep(const struct sk_buff *skb, struct mbo *mbo) u8 *buff = mbo->virt_address; unsigned int mep_len = skb->len + MEP_HDR_LEN; + if (mep_len < skb->len) { + pr_err("drop: too large packet! (%u)\n", skb->len); + return -EINVAL; + } + if (mbo->buffer_length < mep_len) { pr_err("drop: too small buffer! (%d for %d)\n", mbo->buffer_length, mep_len); -- 2.25.0