xhci: dbgtty: Fix unregister on tty_alloc_driver() failure

commit 25b8dfc13495a6c1cf4abacc8ef20196c7f20e5c upstream.

Make sure to set dbc_tty_driver to NULL to match the check in
dbc_tty_exit(). For that, make detached error handling path common to the
other branch in the same function.

Fixes: 4521f1613940 ("xhci: dbctty: split dbc tty driver registration and unregistration functions.")
Cc: stable@vger.kernel.org # v5.10
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lucas De Marchi <ldemarchi@nvidia.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://patch.msgid.link/20260806142113.2436238-9-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c
index d42535ef1978b4a31f81f790dd5491dafa7bb69b..fda5ccaba27a99b6a5df53a3ba4c27e7c7a369d1 100644 (file)
--- a/drivers/usb/host/xhci-dbgtty.c
+++ b/drivers/usb/host/xhci-dbgtty.c
@@ -628,8 +628,8 @@ int dbc_tty_init(void)
        dbc_tty_driver = tty_alloc_driver(64, TTY_DRIVER_REAL_RAW |
                                          TTY_DRIVER_DYNAMIC_DEV);
        if (IS_ERR(dbc_tty_driver)) {
-               idr_destroy(&dbc_tty_minors);
-               return PTR_ERR(dbc_tty_driver);
+               ret = PTR_ERR(dbc_tty_driver);
+               goto fail;
        }
 
        dbc_tty_driver->driver_name = "dbc_serial";
@@ -649,11 +649,17 @@ int dbc_tty_init(void)
        ret = tty_register_driver(dbc_tty_driver);
        if (ret) {
                pr_err("Can't register dbc tty driver\n");
-               tty_driver_kref_put(dbc_tty_driver);
-               idr_destroy(&dbc_tty_minors);
-               dbc_tty_driver = NULL;
+               goto fail_put;
        }
 
+       return ret;
+
+fail_put:
+       tty_driver_kref_put(dbc_tty_driver);
+fail:
+       idr_destroy(&dbc_tty_minors);
+       dbc_tty_driver = NULL;
+
        return ret;
 }