tcp: fix listening_get_next()

Alexey Vlasov found /proc/net/tcp could sometime loop and display
millions of sockets in LISTEN state.

In 2.6.29, when we converted TCP hash tables to RCU, we left two
sk_next() calls in listening_get_next().

We must instead use sk_nulls_next() to properly detect an end of chain.

Reported-by: Alexey Vlasov <renton@renton.name>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2010-12-23 09:32:46 -08:00 committed by David S. Miller
parent b7e03ec9a6
commit 1bde5ac493

View file

@ -2030,7 +2030,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
get_req:
req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
}
sk = sk_next(st->syn_wait_sk);
sk = sk_nulls_next(st->syn_wait_sk);
st->state = TCP_SEQ_STATE_LISTENING;
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
} else {
@ -2039,7 +2039,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
if (reqsk_queue_len(&icsk->icsk_accept_queue))
goto start_req;
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
sk = sk_next(sk);
sk = sk_nulls_next(sk);
}
get_sk:
sk_nulls_for_each_from(sk, node) {