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

Karsten Graul
2019-11-12T15:03:50Z

From: Ursula Braun <ubraun@linux.ibm.com>

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@syzkaller.appspotmail.com
Fixes: 301428ea3708 ("net/smc: fix refcounting for non-blocking connect()")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
net/smc/af_smc.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index cde4dc0ed173..d0271bcb2191 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -799,6 +799,7 @@ static void smc_connect_work(struct 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;
}

--
2.17.1