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 025A1C4361B for ; Mon, 15 Mar 2021 14:03:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D252564EF3 for ; Mon, 15 Mar 2021 14:03:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233555AbhCOOCA (ORCPT ); Mon, 15 Mar 2021 10:02:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:33462 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230217AbhCON4q (ORCPT ); Mon, 15 Mar 2021 09:56:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D6DA464EEC; Mon, 15 Mar 2021 13:56:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816606; bh=qOnis5ASUbtP4DBaEjgypEoRm67TjZW/8eJm0wxkdp4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lrXtmtVSqN2Vp3UCSymhIWNuHLkF58R+eKAvZQC6++gu3f1q43JO/ePjTUmcxnpyH dlOIbz2GgbT3LYD5qn7jRKaqVOzub9lLApaEN9TRcWfg5icuevH0whzmtGredAKMqT H6zOVo8MFYGUfvMClvJd/TXMlM3+PctOYSkmO1jI= 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 5.10 009/290] net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0 Date: Mon, 15 Mar 2021 14:51:42 +0100 Message-Id: <20210315135542.257552702@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135541.921894249@linuxfoundation.org> References: <20210315135541.921894249@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 @@ -14,6 +14,7 @@ #include #include #include +#include static struct sk_buff *mpls_gso_segment(struct sk_buff *skb, netdev_features_t features) @@ -27,6 +28,8 @@ 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;