[PATCH 5.3 13/48] net/smc: fix refcount non-blocking connect() -part 2

From: Greg Kroah-Hartman
Date: Tue Nov 19 2019 - 00:21:09 EST

From: Ursula Braun <ubraun@xxxxxxxxxxxxx>

[ Upstream commit 6d6dd528d5af05dc2d0c773951ed68d630a0c3f1 ]

If an SMC socket is immediately terminated after a non-blocking connect()
has been called, a memory leak is possible.
Due to the sock_hold move in
commit 301428ea3708 ("net/smc: fix refcounting for non-blocking connect()")
an extra sock_put() is needed in smc_connect_work(), if the internal
TCP socket is aborted and cancels the sk_stream_wait_connect() of the
connect worker.

Reported-by: syzbot+4b73ad6fc767e576e275@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 301428ea3708 ("net/smc: fix refcounting for non-blocking connect()")
Signed-off-by: Ursula Braun <ubraun@xxxxxxxxxxxxx>
Signed-off-by: Karsten Graul <kgraul@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
net/smc/af_smc.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -796,6 +796,7 @@ static void smc_connect_work(struct work
smc->sk.sk_err = EPIPE;
else if (signal_pending(current))
smc->sk.sk_err = -sock_intr_errno(timeo);
+ sock_put(&smc->sk); /* passive closing */
goto out;