netdev - [PATCH 18/19] netfilter: xt_hashlimit: fix lock imbalance

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Message-Id: <20180220163906.12380-19-pablo@netfilter.org>
Date:   Tue, 20 Feb 2018 17:39:05 +0100
From:   Pablo Neira Ayuso <pablo@...filter.org>
To:     netfilter-devel@...r.kernel.org
Cc:     davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 18/19] netfilter: xt_hashlimit: fix lock imbalance

From: Eric Dumazet <edumazet@...gle.com>

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@...gle.com>
Reported-by: syzkaller <syzkaller@...glegroups.com>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/netfilter/xt_hashlimit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index aa96027f4418..66f5aca62a08 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;
-- 
2.11.0