From c1201444075009507a6818de6518e2822b9a87c8 Mon Sep 17 00:00:00 2001 From: Wei Wang Date: Tue, 25 Apr 2017 17:38:02 -0700 Subject: [PATCH] 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 Signed-off-by: Wei Wang Acked-by: Eric Dumazet Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller --- net/ipv4/tcp_cong.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c index 79c4817abc94..6e3c512054a6 100644 --- a/net/ipv4/tcp_cong.c +++ b/net/ipv4/tcp_cong.c @@ -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. */