tcp: fix access to sk->sk_state in tcp_poll()

[ Upstream commit d68be71ea14d609a5f31534003319be5db422595 ]

avoid direct access to sk->sk_state when tcp_poll() is called on a socket
using active TCP fastopen with deferred connect. Use local variable
'state', which stores the result of sk_state_load(), like it was done in
commit 00fd38d938db ("tcp: ensure proper barriers in lockless contexts").

Fixes: 19f6d3f3c842 ("net/tcp-fastopen: Add new API support")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Davide Caratti 2017-04-26 19:07:35 +02:00 committed by Greg Kroah-Hartman
parent c0e5b847c7
commit 011fbfb296

View File

@ -533,7 +533,7 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
if (tp->urg_data & TCP_URG_VALID)
mask |= POLLPRI;
} else if (sk->sk_state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {
} else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {
/* Active TCP fastopen socket with defer_connect
* Return POLLOUT so application can call write()
* in order for kernel to generate SYN+data