4.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Wei Wang <weiwan@xxxxxxxxxx>
[ Upstream commit c1201444075009507a6818de6518e2822b9a87c8 ]
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@xxxxxxxxxx>
Signed-off-by: Wei Wang <weiwan@xxxxxxxxxx>
Acked-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Acked-by: Yuchung Cheng <ycheng@xxxxxxxxxx>
Acked-by: Neal Cardwell <ncardwell@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/tcp_cong.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -168,12 +168,8 @@ void tcp_assign_congestion_control(struc
}
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_contro
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. */