From: Patrick McHardy <kaber@xxxxxxxxx>
Use nf_conntrack_hash_rnd in NAT bysource hash to avoid hash chain attacks.
Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
---
net/ipv4/netfilter/nf_nat_core.c | 2 +-
net/netfilter/nf_conntrack_core.c | 1 +
2 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c
index 3346de5..ffb0c94 100644
--- a/net/ipv4/netfilter/nf_nat_core.c
+++ b/net/ipv4/netfilter/nf_nat_core.c
@@ -57,7 +57,7 @@ hash_by_src(const struct net *net, u16 zone,
/* Original src, to ensure we map it consistently if poss. */
hash = jhash_3words((__force u32)tuple->src.u3.ip,
(__force u32)tuple->src.u.all ^ zone,
- tuple->dst.protonum, 0);
+ tuple->dst.protonum, nf_conntrack_hash_rnd);
return ((u64)hash * net->ipv4.nat_htable_size) >> 32;
}
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index f7af8b8..df12969 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -67,6 +67,7 @@ DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
unsigned int nf_conntrack_hash_rnd __read_mostly;
+EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd);
static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone)
{
--
1.7.1
--
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