USB: cdc-acm: fix use-after-free after probe failure

commit 4e49bf376c0451ad2eae2592e093659cde12be9a upstream.

If tty-device registration fails the driver would fail to release the
data interface. When the device is later disconnected, the disconnect
callback would still be called for the data interface and would go about
releasing already freed resources.

Fixes: c93d81955005 ("usb: cdc-acm: fix error handling in acm_probe()")
Cc: stable@vger.kernel.org      # 3.9
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210322155318.9837-3-johan@kernel.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 6fe83c8b16bf4966c33a5da0382df795e005448f..e79359326411ad300987f816d047fb8cb9790b26 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1516,6 +1516,11 @@ skip_countries:
 
        return 0;
 alloc_fail6:
+       if (!acm->combined_interfaces) {
+               /* Clear driver data so that disconnect() returns early. */
+               usb_set_intfdata(data_interface, NULL);
+               usb_driver_release_interface(&acm_driver, data_interface);
+       }
        if (acm->country_codes) {
                device_remove_file(&acm->control->dev,
                                &dev_attr_wCountryCodes);