[PATCH 4.4 095/158] tcp: Reset bytes_acked and bytes_received when disconnecting

Greg Kroah-Hartman
2019-08-02T09:38:57Z

From: Christoph Paasch <cpaasch@apple.com>

[ Upstream commit e858faf556d4e14c750ba1e8852783c6f9520a0e ]

If an app is playing tricks to reuse a socket via tcp_disconnect(),
bytes_acked/received needs to be reset to 0. Otherwise tcp_info will
report the sum of the current and the old connection..

Cc: Eric Dumazet <edumazet@google.com>
Fixes: 0df48c26d841 ("tcp: add tcpi_bytes_acked to tcp_info")
Fixes: bdd1f9edacb5 ("tcp: add tcpi_bytes_received to tcp_info")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv4/tcp.c | 2 ++
1 file changed, 2 insertions(+)

--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2272,6 +2272,8 @@ int tcp_disconnect(struct sock *sk, int
dst_release(sk->sk_rx_dst);
sk->sk_rx_dst = NULL;
tcp_saved_syn_free(tp);
+ tp->bytes_acked = 0;
+ tp->bytes_received = 0;

WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);