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=-19.0 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 03F2CC2BA13 for ; Mon, 15 Mar 2021 14:13:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E020A64F0B for ; Mon, 15 Mar 2021 14:13:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236251AbhCOOMk (ORCPT ); Mon, 15 Mar 2021 10:12:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:35446 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230393AbhCON6j (ORCPT ); Mon, 15 Mar 2021 09:58:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A55F264F22; Mon, 15 Mar 2021 13:58:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816708; bh=30qpCNvgCAC4jJqpN+nWjFnoFgCNXtc8piRFPskl9po=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JV3rwOj/eTDCjOhQ4qVAfOzypgm0iomeQxfRqSx7pbz0sJT2VaEgDktS5Aviv9ROb zB3txZ8A4Ns307aRqaeaVEX0GwbR8mC9CgP3w+7TISU6YVeBSIWNOxMgMZXPL9qL20 Ly74oeV4ftrSaxyheSA20mAq8v2DUOgrp3eIMVXw= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Balazs Nemeth , Willem de Bruijn , David Ahern , "David S. Miller" Subject: [PATCH 4.19 019/120] net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0 Date: Mon, 15 Mar 2021 14:56:10 +0100 Message-Id: <20210315135720.638602447@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135720.002213995@linuxfoundation.org> References: <20210315135720.002213995@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: Greg Kroah-Hartman From: Balazs Nemeth commit d348ede32e99d3a04863e9f9b28d224456118c27 upstream. A packet with skb_inner_network_header(skb) == skb_network_header(skb) and ETH_P_MPLS_UC will prevent mpls_gso_segment from pulling any headers from the packet. Subsequently, the call to skb_mac_gso_segment will again call mpls_gso_segment with the same packet leading to an infinite loop. In addition, ensure that the header length is a multiple of four, which should hold irrespective of the number of stacked labels. Signed-off-by: Balazs Nemeth Acked-by: Willem de Bruijn Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/mpls/mpls_gso.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/mpls/mpls_gso.c +++ b/net/mpls/mpls_gso.c @@ -18,6 +18,7 @@ #include #include #include +#include static struct sk_buff *mpls_gso_segment(struct sk_buff *skb, netdev_features_t features) @@ -31,6 +32,8 @@ static struct sk_buff *mpls_gso_segment( skb_reset_network_header(skb); mpls_hlen = skb_inner_network_header(skb) - skb_network_header(skb); + if (unlikely(!mpls_hlen || mpls_hlen % MPLS_HLEN)) + goto out; if (unlikely(!pskb_may_pull(skb, mpls_hlen))) goto out;