usb: misc: fix improper handling of refcount in uss720_probe()

commit 0a96fa640dc928da9eaa46a22c46521b037b78ad upstream.

usb_put_dev shouldn't be called when uss720_probe succeeds because of
priv->usbdev. At the same time, priv->usbdev shouldn't be set to NULL
before destroy_priv in uss720_disconnect because usb_put_dev is in
destroy_priv.

Fix this by moving priv->usbdev = NULL after usb_put_dev.

Fixes: dcb4b8ad6a44 ("misc/uss720: fix memory leak in uss720_probe")
Cc: stable <stable@kernel.org>
Reviewed-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Link: https://lore.kernel.org/r/20220407024001.11761-1-hbh25y@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/misc/uss720.c b/drivers/usb/misc/uss720.c
index 748139d..0be8efc 100644 (file)
--- a/drivers/usb/misc/uss720.c
+++ b/drivers/usb/misc/uss720.c
@@ -71,6 +71,7 @@ static void destroy_priv(struct kref *kref)
 
        dev_dbg(&priv->usbdev->dev, "destroying priv datastructure\n");
        usb_put_dev(priv->usbdev);
+       priv->usbdev = NULL;
        kfree(priv);
 }
 
@@ -736,7 +737,6 @@ static int uss720_probe(struct usb_interface *intf,
        parport_announce_port(pp);
 
        usb_set_intfdata(intf, pp);
-       usb_put_dev(usbdev);
        return 0;
 
 probe_abort:
@@ -754,7 +754,6 @@ static void uss720_disconnect(struct usb_interface *intf)
        usb_set_intfdata(intf, NULL);
        if (pp) {
                priv = pp->private_data;
-               priv->usbdev = NULL;
                priv->pp = NULL;
                dev_dbg(&intf->dev, "parport_remove_port\n");
                parport_remove_port(pp);