]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
netfilter: nat: fix ICMP header corruption on ICMP errors
authorEyal Birger <eyal.birger@gmail.com>
Tue, 14 Jan 2020 08:03:50 +0000 (10:03 +0200)
committerPablo Neira Ayuso <pablo@netfilter.org>
Thu, 16 Jan 2020 14:08:25 +0000 (15:08 +0100)
commit61177e911dad660df86a4553eb01c95ece2f6a82
tree8ea08f4c27ddc1e25d3ec0a0f0602436efe68a61
parent335178d5429c4cee61b58f4ac80688f556630818
netfilter: nat: fix ICMP header corruption on ICMP errors

Commit 8303b7e8f018 ("netfilter: nat: fix spurious connection timeouts")
made nf_nat_icmp_reply_translation() use icmp_manip_pkt() as the l4
manipulation function for the outer packet on ICMP errors.

However, icmp_manip_pkt() assumes the packet has an 'id' field which
is not correct for all types of ICMP messages.

This is not correct for ICMP error packets, and leads to bogus bytes
being written the ICMP header, which can be wrongfully regarded as
'length' bytes by RFC 4884 compliant receivers.

Fix by assigning the 'id' field only for ICMP messages that have this
semantic.

Reported-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Fixes: 8303b7e8f018 ("netfilter: nat: fix spurious connection timeouts")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
net/netfilter/nf_nat_proto.c