tcp: memset ca_priv data to 0 properly

Always zero out ca_priv data in tcp_assign_congestion_control() so that
ca_priv data is cleared out during socket creation.
Also always zero out ca_priv data in tcp_reinit_congestion_control() so
that when cc algorithm is changed, ca_priv data is cleared out as well.
We should still zero out ca_priv data even in TCP_CLOSE state because
user could call connect() on AF_UNSPEC to disconnect the socket and
leave it in TCP_CLOSE state and later call setsockopt() to switch cc
algorithm on this socket.

Fixes: 2b0a8c9ee ("tcp: add CDG congestion control")
Reported-by: Andrey Konovalov  <andreyknvl@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wei Wang 2017-04-25 17:38:02 -07:00 committed by David S. Miller
parent 199ab00f3c
commit c120144407

View file

@ -168,12 +168,8 @@ void tcp_assign_congestion_control(struct sock *sk)
}
out:
rcu_read_unlock();
memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));
/* Clear out private data before diag gets it and
* the ca has not been initialized.
*/
if (ca->get_info)
memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));
if (ca->flags & TCP_CONG_NEEDS_ECN)
INET_ECN_xmit(sk);
else
@ -200,11 +196,10 @@ static void tcp_reinit_congestion_control(struct sock *sk,
tcp_cleanup_congestion_control(sk);
icsk->icsk_ca_ops = ca;
icsk->icsk_ca_setsockopt = 1;
memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));
if (sk->sk_state != TCP_CLOSE) {
memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));
if (sk->sk_state != TCP_CLOSE)
tcp_init_congestion_control(sk);
}
}
/* Manage refcounts on socket close. */