[Patch net] xt_RATEEST: acquire xt_rateest_mutex for hash insert

[Cong Wang]

rateest_hash is supposed to be protected by xt_rateest_mutex.

Reported-by: <syzbot+5cb189720978275e4...@syzkaller.appspotmail.com>
Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target")
Cc: Pablo Neira Ayuso <pa...@netfilter.org>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
---
 net/netfilter/xt_RATEEST.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
index 498b54fd04d7..83ec3a282755 100644
--- a/net/netfilter/xt_RATEEST.c
+++ b/net/netfilter/xt_RATEEST.c
@@ -36,7 +36,9 @@ static void xt_rateest_hash_insert(struct xt_rateest *est)
        unsigned int h;
 
        h = xt_rateest_hash(est->name);
+       mutex_lock(&xt_rateest_mutex);
        hlist_add_head(&est->list, &rateest_hash[h]);
+       mutex_unlock(&xt_rateest_mutex);
 }
 
 struct xt_rateest *xt_rateest_lookup(const char *name)
-- 
2.13.0