From: Sven Auhagen sven.auhagen@voleatech.de
[ 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: ac2a66665e23 ("netfilter: add generic flow table infrastructure") Signed-off-by: Sven Auhagen sven.auhagen@voleatech.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nf_flow_table_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c index 513f78db3cb2f..4a4acbba78ff7 100644 --- a/net/netfilter/nf_flow_table_core.c +++ b/net/netfilter/nf_flow_table_core.c @@ -399,7 +399,7 @@ 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; } @@ -415,7 +415,7 @@ 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; }