Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1bde5ac4 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

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: default avatarAlexey Vlasov <renton@renton.name>
Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b7e03ec9

net/ipv4/tcp_ipv4.c

+2 −2
Original line number Diff line number Diff line
@@ -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) {