If resource allocation and registration fail for a muxed tty device (e.g. if there are no more minor numbers) the driver should not try to deregister the never-registered tty.
Fix up the error handling to avoid dereferencing a NULL pointer when attempting to remove the character device:
BUG: kernel NULL pointer dereference, address: 0000000000000064 [...] RIP: 0010:cdev_del+0x4/0x20 [...] Call Trace: tty_unregister_device+0x34/0x50 hso_probe+0x1d1/0x57e [hso]
Fixes: 72dc1c096c70 ("HSO: add option hso driver") Cc: stable@vger.kernel.org # 2.6.27 Signed-off-by: Johan Hovold johan@kernel.org --- drivers/net/usb/hso.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index cfad5b36bd8e..81ff54e9587f 100644 --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -2710,14 +2710,14 @@ struct hso_device *hso_create_mux_serial_device(struct usb_interface *interface,
serial = kzalloc(sizeof(*serial), GFP_KERNEL); if (!serial) - goto exit; + goto err_free_dev;
hso_dev->port_data.dev_serial = serial; serial->parent = hso_dev;
if (hso_serial_common_create (serial, 1, CTRL_URB_RX_SIZE, CTRL_URB_TX_SIZE)) - goto exit; + goto err_free_serial;
serial->tx_data_length--; serial->write_data = hso_mux_serial_write_data; @@ -2733,11 +2733,9 @@ struct hso_device *hso_create_mux_serial_device(struct usb_interface *interface, /* done, return it */ return hso_dev;
-exit: - if (serial) { - tty_unregister_device(tty_drv, serial->minor); - kfree(serial); - } +err_free_serial: + kfree(serial); +err_free_dev: kfree(hso_dev); return NULL;