[PATCH 4.14 099/146] tipc: fix hanging poll() for stream sockets

Greg Kroah-Hartman
2018-01-01T14:56:59Z

From: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>

[ Upstream commit 517d7c79bdb39864e617960504bdc1aa560c75c6 ]

In commit 42b531de17d2f6 ("tipc: Fix missing connection request
handling"), we replaced unconditional wakeup() with condtional
wakeup for clients with flags POLLIN | POLLRDNORM | POLLRDBAND.

This breaks the applications which do a connect followed by poll
with POLLOUT flag. These applications are not woken when the
connection is ESTABLISHED and hence sleep forever.

In this commit, we fix it by including the POLLOUT event for
sockets in TIPC_CONNECTING state.

Fixes: 42b531de17d2f6 ("tipc: Fix missing connection request handling")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/tipc/socket.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -709,11 +709,11 @@ static unsigned int tipc_poll(struct fil

switch (sk->sk_state) {
case TIPC_ESTABLISHED:
+ case TIPC_CONNECTING:
if (!tsk->cong_link_cnt && !tsk_conn_cong(tsk))
mask |= POLLOUT;
/* fall thru' */
case TIPC_LISTEN:
- case TIPC_CONNECTING:
if (!skb_queue_empty(&sk->sk_receive_queue))
mask |= (POLLIN | POLLRDNORM);
break;