From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-4098462-1520451954-2-1162487212712337572 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1520451952; b=WRMiIgXtYcN7+QNjaLn0syUqL3Wke95XzgSMhGtmDZubEHI Ok/BwPNMiInK8wKwmHgVdE4TT7tXjsEqpRW6mvMz8kp7doN4Ew68wI6LMcmKnPtX Sqmiq18E5MErRK86FvkRUm06Z+DS7FUiFd8lVT8PfVAdgR3vmB51wHmp/Onf87if cMHsjK+2bSRZRSk2iLrMCicRez2XOpi4bVJWZF/R/tFfLJeWa60IrnFRrhXBZbuV 7fzI2pvOVbcvRUGDeuGwi35U8ctFN3dsLe791hg+AbCsXx+C/h72ZC0ucoeRcjCA TKXbJsFq+j0YHjT9xT/f95nvbwgtKyJLVYAOYrw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1520451952; bh=Uf7TqdIrW+meg14VCZftgv+sTF UEkZRB8eC/3hiQjjE=; b=cxLUX+vA8u1/c6vn8YOlB8P3TboRJ775nQIk4l3wOE K68qMdC0RLMwVIIMP10CxsZH28bAZUfCeOzvnrtzq7Z1ZcdllVedXjoE1Tu58fW1 LAV7QJWn3YFsSd61b52UwPZ4VsIA2r15dq9FAwiq3dQaoCO7evpSrnAZbxABcaoW NhLi7o6nTTITgvTLlOp3duLwmkRJTgrRozUJaF+7Gp5n1hZPnUXnPRdv6x0l2sKG C+5v8o0vePyXfEVNTrEv32k0+QAIeyjv/gCcFmJWDm1scTmzqzfFNp/chUIWKBdh I6pzHSUJpStEh4B0CI0G40BhwlG9/SVoS+5DL+HxKoFg== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=-100 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=-100 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965392AbeCGTpt (ORCPT ); Wed, 7 Mar 2018 14:45:49 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:44300 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965391AbeCGTpq (ORCPT ); Wed, 7 Mar 2018 14:45:46 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jianlin Shi , Sabrina Dubroca , Stefano Brivio , "David S. Miller" Subject: [PATCH 4.14 041/110] net: ipv4: dont allow setting net.ipv4.route.min_pmtu below 68 Date: Wed, 7 Mar 2018 11:38:24 -0800 Message-Id: <20180307191045.010229697@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180307191039.748351103@linuxfoundation.org> References: <20180307191039.748351103@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sabrina Dubroca [ Upstream commit c7272c2f1229125f74f22dcdd59de9bbd804f1c8 ] According to RFC 1191 sections 3 and 4, ICMP frag-needed messages indicating an MTU below 68 should be rejected: A host MUST never reduce its estimate of the Path MTU below 68 octets. and (talking about ICMP frag-needed's Next-Hop MTU field): This field will never contain a value less than 68, since every router "must be able to forward a datagram of 68 octets without fragmentation". Furthermore, by letting net.ipv4.route.min_pmtu be set to negative values, we can end up with a very large PMTU when (-1) is cast into u32. Let's also make ip_rt_min_pmtu a u32, since it's only ever compared to unsigned ints. Reported-by: Jianlin Shi Signed-off-by: Sabrina Dubroca Reviewed-by: Stefano Brivio Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/route.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -128,10 +128,13 @@ static int ip_rt_redirect_silence __read static int ip_rt_error_cost __read_mostly = HZ; static int ip_rt_error_burst __read_mostly = 5 * HZ; static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; -static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; +static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; static int ip_rt_min_advmss __read_mostly = 256; static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; + +static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; + /* * Interface to generic destination cache. */ @@ -2934,7 +2937,8 @@ static struct ctl_table ipv4_route_table .data = &ip_rt_min_pmtu, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = proc_dointvec_minmax, + .extra1 = &ip_min_valid_pmtu, }, { .procname = "min_adv_mss",