From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933369AbcEQBpb (ORCPT ); Mon, 16 May 2016 21:45:31 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34455 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932318AbcEQB0s (ORCPT ); Mon, 16 May 2016 21:26:48 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paolo Abeni , "David S. Miller" Subject: [PATCH 4.5 043/101] net/route: enforce hoplimit max value Date: Mon, 16 May 2016 18:20:48 -0700 Message-Id: <20160517011507.968129815@linuxfoundation.org> X-Mailer: git-send-email 2.8.2 In-Reply-To: <20160517011506.359924439@linuxfoundation.org> References: <20160517011506.359924439@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni [ Upstream commit 626abd59e51d4d8c6367e03aae252a8aa759ac78 ] Currently, when creating or updating a route, no check is performed in both ipv4 and ipv6 code to the hoplimit value. The caller can i.e. set hoplimit to 256, and when such route will be used, packets will be sent with hoplimit/ttl equal to 0. This commit adds checks for the RTAX_HOPLIMIT value, in both ipv4 ipv6 route code, substituting any value greater than 255 with 255. This is consistent with what is currently done for ADVMSS and MTU in the ipv4 code. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/fib_semantics.c | 2 ++ net/ipv6/route.c | 2 ++ 2 files changed, 4 insertions(+) --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -975,6 +975,8 @@ fib_convert_metrics(struct fib_info *fi, val = 65535 - 40; if (type == RTAX_MTU && val > 65535 - 15) val = 65535 - 15; + if (type == RTAX_HOPLIMIT && val > 255) + val = 255; if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK)) return -EINVAL; fi->fib_metrics[type - 1] = val; --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1737,6 +1737,8 @@ static int ip6_convert_metrics(struct mx } else { val = nla_get_u32(nla); } + if (type == RTAX_HOPLIMIT && val > 255) + val = 255; if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK)) goto err;