netfilter: xt_hashlimit: fix lock imbalance
syszkaller found that rcu was not held in hashlimit_mt_common()
We only need to enable BH at this point.
Fixes: bea74641e378 ("netfilter: xt_hashlimit: add rate match mode")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index aa96027..66f5aca 100644
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -775,7 +775,7 @@ hashlimit_mt_common(const struct sk_buff *skb, struct xt_action_param *par,
if (!dh->rateinfo.prev_window &&
(dh->rateinfo.current_rate <= dh->rateinfo.burst)) {
spin_unlock(&dh->lock);
- rcu_read_unlock_bh();
+ local_bh_enable();
return !(cfg->mode & XT_HASHLIMIT_INVERT);
} else {
goto overlimit;