linux-kernel - [PATCH 5.6 053/118] wireguard: receive: use tunnel helpers for decapsulating ECN markings

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 13 May 2020 11:44:32 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Olivier Tilmans <olivier.tilmans@...ia-bell-labs.com>,
        Dave Taht <dave.taht@...il.com>,
        "Rodney W. Grimes" <ietf@...rsh.dnsmgr.net>,
        Toke HÃ¸iland-JÃ¸rgensen <toke@...hat.com>,
        "Jason A. Donenfeld" <Jason@...c4.com>,
        "David S. Miller" <davem@...emloft.net>
Subject: [PATCH 5.6 053/118] wireguard: receive: use tunnel helpers for decapsulating ECN markings

From: "Toke Høiland-Jørgensen" <toke@...hat.com>

[ Upstream commit eebabcb26ea1e3295704477c6cd4e772c96a9559 ]

WireGuard currently only propagates ECN markings on tunnel decap according
to the old RFC3168 specification. However, the spec has since been updated
in RFC6040 to recommend slightly different decapsulation semantics. This
was implemented in the kernel as a set of common helpers for ECN
decapsulation, so let's just switch over WireGuard to using those, so it
can benefit from this enhancement and any future tweaks. We do not drop
packets with invalid ECN marking combinations, because WireGuard is
frequently used to work around broken ISPs, which could be doing that.

Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Reported-by: Olivier Tilmans <olivier.tilmans@...ia-bell-labs.com>
Cc: Dave Taht <dave.taht@...il.com>
Cc: Rodney W. Grimes <ietf@...rsh.dnsmgr.net>
Signed-off-by: Toke HÃ¸iland-JÃ¸rgensen <toke@...hat.com>
Signed-off-by: Jason A. Donenfeld <Jason@...c4.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/net/wireguard/receive.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

--- a/drivers/net/wireguard/receive.c
+++ b/drivers/net/wireguard/receive.c
@@ -393,13 +393,11 @@ static void wg_packet_consume_data_done(
 		len = ntohs(ip_hdr(skb)->tot_len);
 		if (unlikely(len < sizeof(struct iphdr)))
 			goto dishonest_packet_size;
-		if (INET_ECN_is_ce(PACKET_CB(skb)->ds))
-			IP_ECN_set_ce(ip_hdr(skb));
+		INET_ECN_decapsulate(skb, PACKET_CB(skb)->ds, ip_hdr(skb)->tos);
 	} else if (skb->protocol == htons(ETH_P_IPV6)) {
 		len = ntohs(ipv6_hdr(skb)->payload_len) +
 		      sizeof(struct ipv6hdr);
-		if (INET_ECN_is_ce(PACKET_CB(skb)->ds))
-			IP6_ECN_set_ce(skb, ipv6_hdr(skb));
+		INET_ECN_decapsulate(skb, PACKET_CB(skb)->ds, ipv6_get_dsfield(ipv6_hdr(skb)));
 	} else {
 		goto dishonest_packet_type;
 	}