[PATCH AUTOSEL 4.14 126/371] netfilter: nft_set_hash: fix lookups with fixed size hash on big endian

Sasha Levin
2020-01-16T18:30:41Z

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit 3b02b0adc242a72b5e46019b6a9e4f84823592f6 ]

Call jhash_1word() for the 4-bytes key case from the insertion and
deactivation path, otherwise big endian arch set lookups fail.

Fixes: 446a8268b7f5 ("netfilter: nft_set_hash: add lookup variant for fixed size hashtable")
Reported-by: Florian Westphal <fw@strlen.de>
Tested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nft_set_hash.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 33aa2ac3a62e..73f8f99b1193 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -442,6 +442,23 @@ static bool nft_hash_lookup_fast(const struct net *net,
return false;
}

+static u32 nft_jhash(const struct nft_set *set, const struct nft_hash *priv,
+ const struct nft_set_ext *ext)
+{
+ const struct nft_data *key = nft_set_ext_key(ext);
+ u32 hash, k1;
+
+ if (set->klen == 4) {
+ k1 = *(u32 *)key;
+ hash = jhash_1word(k1, priv->seed);
+ } else {
+ hash = jhash(key, set->klen, priv->seed);
+ }
+ hash = reciprocal_scale(hash, priv->buckets);
+
+ return hash;
+}
+
static int nft_hash_insert(const struct net *net, const struct nft_set *set,
const struct nft_set_elem *elem,
struct nft_set_ext **ext)
@@ -451,8 +468,7 @@ static int nft_hash_insert(const struct net *net, const struct nft_set *set,
u8 genmask = nft_genmask_next(net);
u32 hash;

- hash = jhash(nft_set_ext_key(&this->ext), set->klen, priv->seed);
- hash = reciprocal_scale(hash, priv->buckets);
+ hash = nft_jhash(set, priv, &this->ext);
hlist_for_each_entry(he, &priv->table[hash], node) {
if (!memcmp(nft_set_ext_key(&this->ext),
nft_set_ext_key(&he->ext), set->klen) &&
@@ -491,8 +507,7 @@ static void *nft_hash_deactivate(const struct net *net,
u8 genmask = nft_genmask_next(net);
u32 hash;

- hash = jhash(nft_set_ext_key(&this->ext), set->klen, priv->seed);
- hash = reciprocal_scale(hash, priv->buckets);
+ hash = nft_jhash(set, priv, &this->ext);
hlist_for_each_entry(he, &priv->table[hash], node) {
if (!memcmp(nft_set_ext_key(&this->ext), &elem->key.val,
set->klen) ||
--
2.20.1