From: Florian Westphal <fw@xxxxxxxxx> commit 6bac76db1da3cb162c425d58ae421486f8e43955 upstream. Due to copy&paste error nf_nat_mangle_udp_packet passes IPPROTO_TCP, resulting in incorrect udp checksum when payload had to be mangled. Fixes: dac3fe72596f9 ("netfilter: nat: remove csum_recalc hook") Reported-by: Marc Haber <mh+netdev@xxxxxxxxxxxx> Tested-by: Marc Haber <mh+netdev@xxxxxxxxxxxx> Signed-off-by: Florian Westphal <fw@xxxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/netfilter/nf_nat_helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/netfilter/nf_nat_helper.c +++ b/net/netfilter/nf_nat_helper.c @@ -170,7 +170,7 @@ nf_nat_mangle_udp_packet(struct sk_buff if (!udph->check && skb->ip_summed != CHECKSUM_PARTIAL) return true; - nf_nat_csum_recalc(skb, nf_ct_l3num(ct), IPPROTO_TCP, + nf_nat_csum_recalc(skb, nf_ct_l3num(ct), IPPROTO_UDP, udph, &udph->check, datalen, oldlen); return true;