usb: cdc-acm: fix error handling in acm_probe()

acm_probe() ignores errors in tty_port_register_device()
and leaves intfdata pointing to freed memory on alloc_fail7
error path. The patch fixes the both issues.

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

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 8ac25adf31b41d857a6919299f1848cf2ee43710..c125b61c24998cf69faea1372817de14240febcd 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -977,6 +977,8 @@ static int acm_probe(struct usb_interface *intf,
        int num_rx_buf;
        int i;
        int combined_interfaces = 0;
+       struct device *tty_dev;
+       int rv = -ENOMEM;
 
        /* normal quirks */
        quirks = (unsigned long)id->driver_info;
@@ -1339,11 +1341,24 @@ skip_countries:
        usb_set_intfdata(data_interface, acm);
 
        usb_get_intf(control_interface);
-       tty_port_register_device(&acm->port, acm_tty_driver, minor,
+       tty_dev = tty_port_register_device(&acm->port, acm_tty_driver, minor,
                        &control_interface->dev);
+       if (IS_ERR(tty_dev)) {
+               rv = PTR_ERR(tty_dev);
+               goto alloc_fail8;
+       }
 
        return 0;
+alloc_fail8:
+       if (acm->country_codes) {
+               device_remove_file(&acm->control->dev,
+                               &dev_attr_wCountryCodes);
+               device_remove_file(&acm->control->dev,
+                               &dev_attr_iCountryCodeRelDate);
+       }
+       device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
 alloc_fail7:
+       usb_set_intfdata(intf, NULL);
        for (i = 0; i < ACM_NW; i++)
                usb_free_urb(acm->wb[i].urb);
 alloc_fail6:
@@ -1359,7 +1374,7 @@ alloc_fail2:
        acm_release_minor(acm);
        kfree(acm);
 alloc_fail:
-       return -ENOMEM;
+       return rv;
 }
 
 static void stop_data_traffic(struct acm *acm)