From patchwork Tue Sep 15 14:12:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 309647 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=-15.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 E04BCC2D0E3 for ; Tue, 15 Sep 2020 23:41:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A7BEC20720 for ; Tue, 15 Sep 2020 23:41:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600213309; bh=6lJqYousbkRWzTnKPucX719ewW66jKHGJq1Or/5QNn8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DXmIN27HAmz+lECS8GCVdsz7KUhSjW/2wo1Crxvfy3IIpoJ/BIhmNxAsDtS/ctVZ1 JenIrlOSYZ5ulLZhZZPUnUBP5MdEg2MBhBcVmzULhl8xlC7AF2s1vLQamzxTm3UvBa 1czJrZoETF/eNFLBbGCIkhx0OlbwfuC87oAI/AVI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727464AbgIOXlp (ORCPT ); Tue, 15 Sep 2020 19:41:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:46444 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727108AbgIOOem (ORCPT ); Tue, 15 Sep 2020 10:34:42 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 50EF721D91; Tue, 15 Sep 2020 14:15:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600179333; bh=6lJqYousbkRWzTnKPucX719ewW66jKHGJq1Or/5QNn8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2CLYtzkO/9UM9YfzWcQignThgXtcAAkw3uplwCBaXgJ5cZOHmrtIsCPtulFq0twmf 6+GGXMzlYnue8IQv6/WquorLljHIuulVu4AkG9Ush48nrzdHXbwR5jIPN6i8N0s4Na AwspHp1xbGLAuWmGENuN0i2JBsALGzVUFXhMyOqA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Westphal , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 4.19 19/78] netfilter: conntrack: allow sctp hearbeat after connection re-use Date: Tue, 15 Sep 2020 16:12:44 +0200 Message-Id: <20200915140634.526206757@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200915140633.552502750@linuxfoundation.org> References: <20200915140633.552502750@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Florian Westphal [ Upstream commit cc5453a5b7e90c39f713091a7ebc53c1f87d1700 ] If an sctp connection gets re-used, heartbeats are flagged as invalid because their vtag doesn't match. Handle this in a similar way as TCP conntrack when it suspects that the endpoints and conntrack are out-of-sync. When a HEARTBEAT request fails its vtag validation, flag this in the conntrack state and accept the packet. When a HEARTBEAT_ACK is received with an invalid vtag in the reverse direction after we allowed such a HEARTBEAT through, assume we are out-of-sync and re-set the vtag info. v2: remove left-over snippet from an older incarnation that moved new_state/old_state assignments, thats not needed so keep that as-is. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- include/linux/netfilter/nf_conntrack_sctp.h | 2 ++ net/netfilter/nf_conntrack_proto_sctp.c | 39 ++++++++++++++++++--- 2 files changed, 37 insertions(+), 4 deletions(-) diff --git a/include/linux/netfilter/nf_conntrack_sctp.h b/include/linux/netfilter/nf_conntrack_sctp.h index 9a33f171aa822..625f491b95de8 100644 --- a/include/linux/netfilter/nf_conntrack_sctp.h +++ b/include/linux/netfilter/nf_conntrack_sctp.h @@ -9,6 +9,8 @@ struct ip_ct_sctp { enum sctp_conntrack state; __be32 vtag[IP_CT_DIR_MAX]; + u8 last_dir; + u8 flags; }; #endif /* _NF_CONNTRACK_SCTP_H */ diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c index 7d7e30ea0ecf9..a937d4f75613f 100644 --- a/net/netfilter/nf_conntrack_proto_sctp.c +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -65,6 +65,8 @@ static const unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] = { [SCTP_CONNTRACK_HEARTBEAT_ACKED] = 210 SECS, }; +#define SCTP_FLAG_HEARTBEAT_VTAG_FAILED 1 + #define sNO SCTP_CONNTRACK_NONE #define sCL SCTP_CONNTRACK_CLOSED #define sCW SCTP_CONNTRACK_COOKIE_WAIT @@ -288,6 +290,7 @@ static int sctp_packet(struct nf_conn *ct, u_int32_t offset, count; unsigned int *timeouts; unsigned long map[256 / sizeof(unsigned long)] = { 0 }; + bool ignore = false; sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph); if (sh == NULL) @@ -332,15 +335,39 @@ static int sctp_packet(struct nf_conn *ct, /* Sec 8.5.1 (D) */ if (sh->vtag != ct->proto.sctp.vtag[dir]) goto out_unlock; - } else if (sch->type == SCTP_CID_HEARTBEAT || - sch->type == SCTP_CID_HEARTBEAT_ACK) { + } else if (sch->type == SCTP_CID_HEARTBEAT) { + if (ct->proto.sctp.vtag[dir] == 0) { + pr_debug("Setting %d vtag %x for dir %d\n", sch->type, sh->vtag, dir); + ct->proto.sctp.vtag[dir] = sh->vtag; + } else if (sh->vtag != ct->proto.sctp.vtag[dir]) { + if (test_bit(SCTP_CID_DATA, map) || ignore) + goto out_unlock; + + ct->proto.sctp.flags |= SCTP_FLAG_HEARTBEAT_VTAG_FAILED; + ct->proto.sctp.last_dir = dir; + ignore = true; + continue; + } else if (ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) { + ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED; + } + } else if (sch->type == SCTP_CID_HEARTBEAT_ACK) { if (ct->proto.sctp.vtag[dir] == 0) { pr_debug("Setting vtag %x for dir %d\n", sh->vtag, dir); ct->proto.sctp.vtag[dir] = sh->vtag; } else if (sh->vtag != ct->proto.sctp.vtag[dir]) { - pr_debug("Verification tag check failed\n"); - goto out_unlock; + if (test_bit(SCTP_CID_DATA, map) || ignore) + goto out_unlock; + + if ((ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) == 0 || + ct->proto.sctp.last_dir == dir) + goto out_unlock; + + ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED; + ct->proto.sctp.vtag[dir] = sh->vtag; + ct->proto.sctp.vtag[!dir] = 0; + } else if (ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) { + ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED; } } @@ -375,6 +402,10 @@ static int sctp_packet(struct nf_conn *ct, } spin_unlock_bh(&ct->lock); + /* allow but do not refresh timeout */ + if (ignore) + return NF_ACCEPT; + timeouts = nf_ct_timeout_lookup(ct); if (!timeouts) timeouts = sctp_pernet(nf_ct_net(ct))->timeouts;