farsync: add module_put to error path in fst_open()

The fst_open() function, after a successful try_module_get() may return
an error code if hdlc_open() returns it.  However, it does not put the
module on this error path.

This patch adds the necessary module_put() call.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Pavel Shved <shved@ispras.ru>
Signed-off-by: David S. Miller <davem@conan.davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/net/wan/farsync.c b/drivers/net/wan/farsync.c
index e050bd65e037..777d1a4e81b2 100644
--- a/drivers/net/wan/farsync.c
+++ b/drivers/net/wan/farsync.c
@@ -2203,8 +2203,10 @@ fst_open(struct net_device *dev)
 
         if (port->mode != FST_RAW) {
                 err = hdlc_open(dev);
-                if (err)
+                if (err) {
+                        module_put(THIS_MODULE);
                         return err;
+                }
         }
 
         fst_openport(port);