summaryrefslogtreecommitdiffstats
path: root/net
diff options
context:
space:
mode:
authorFlorian Westphal <fw@strlen.de>2019-04-09 14:45:20 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2019-04-15 07:31:50 +0200
commit5bdac418f33f60b07a34e01e722889140ee8fac9 (patch)
tree8dd81d36f4c9ba89f4ad8779f8055e24f8069118 /net
parent33d1c018179d0a30c39cc5f1682b77867282694b (diff)
downloadlinux-5bdac418f33f60b07a34e01e722889140ee8fac9.tar.bz2
netfilter: nat: fix icmp id randomization
Sven Auhagen reported that a 2nd ping request will fail if 'fully-random' mode is used. Reason is that if no proto information is given, min/max are both 0, so we set the icmp id to 0 instead of chosing a random value between 0 and 65535. Update test case as well to catch this, without fix this yields: [..] ERROR: cannot ping ns1 from ns2 with ip masquerade fully-random (attempt 2) ERROR: cannot ping ns1 from ns2 with ipv6 masquerade fully-random (attempt 2) ... becaus 2nd ping clashes with existing 'id 0' icmp conntrack and gets dropped. Fixes: 203f2e78200c27e ("netfilter: nat: remove l4proto->unique_tuple") Reported-by: Sven Auhagen <sven.auhagen@voleatech.de> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_nat_core.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index af7dc6537758..000952719adf 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -415,9 +415,14 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
case IPPROTO_ICMPV6:
/* id is same for either direction... */
keyptr = &tuple->src.u.icmp.id;
- min = range->min_proto.icmp.id;
- range_size = ntohs(range->max_proto.icmp.id) -
- ntohs(range->min_proto.icmp.id) + 1;
+ if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
+ min = 0;
+ range_size = 65536;
+ } else {
+ min = ntohs(range->min_proto.icmp.id);
+ range_size = ntohs(range->max_proto.icmp.id) -
+ ntohs(range->min_proto.icmp.id) + 1;
+ }
goto find_free_id;
#if IS_ENABLED(CONFIG_NF_CT_PROTO_GRE)
case IPPROTO_GRE: