Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 99109999 authored by Sven Auhagen's avatar Sven Auhagen Committed by Greg Kroah-Hartman
Browse files

netfilter: flowtable: fix tcp and udp header checksum update 



[ Upstream commit 8d6bca156e47d68551750a384b3ff49384c67be3 ]

When updating the tcp or udp header checksum on port nat the function
inet_proto_csum_replace2 with the last parameter pseudohdr as true.
This leads to an error in the case that GRO is used and packets are
split up in GSO. The tcp or udp checksum of all packets is incorrect.

The error is probably masked due to the fact the most network driver
implement tcp/udp checksum offloading. It also only happens when GRO is
applied and not on single packets.

The error is most visible when using a pppoe connection which is not
triggering the tcp/udp checksum offload.

Fixes: ac2a6666 ("netfilter: add generic flow table infrastructure")
Signed-off-by: default avatarSven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 28198be7

net/netfilter/nf_flow_table_core.c

+2 −2
Original line number Diff line number Diff line
@@ -360,7 +360,7 @@ static int nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff, 
		return -1;



	tcph = (void *)(skb_network_header(skb) + thoff);

	inet_proto_csum_replace2(&tcph->check, skb, port, new_port, true);

	inet_proto_csum_replace2(&tcph->check, skb, port, new_port, false);



	return 0;

}
@@ -377,7 +377,7 @@ static int nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff, 
	udph = (void *)(skb_network_header(skb) + thoff);

	if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {

		inet_proto_csum_replace2(&udph->check, skb, port,

					 new_port, true);

					 new_port, false);

		if (!udph->check)

			udph->check = CSUM_MANGLED_0;

	}