diff options
| author | Johan Hovold <johan@kernel.org> | 2015-01-05 16:04:13 +0100 |
|---|---|---|
| committer | Johan Hovold <johan@kernel.org> | 2015-01-10 12:48:21 +0100 |
| commit | 32a4bf2e81ec378e5925d4e069e0677a6c86a6ad (patch) | |
| tree | 7060d862f8df27bd46007e6d30ac38ca2e8eafa2 /drivers | |
| parent | d269d4434c72ed0da3a9b1230c30da82c4918c63 (diff) | |
USB: console: fix potential use after free
Use tty kref to release the fake tty in usb_console_setup to avoid use
after free if the underlying serial driver has acquired a reference.
Note that using the tty destructor release_one_tty requires some more
state to be initialised.
Fixes: 4a90f09b20f4 ("tty: usb-serial krefs")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/serial/console.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/usb/serial/console.c b/drivers/usb/serial/console.c index e56f394b58d8..29fa1c3d0089 100644 --- a/drivers/usb/serial/console.c +++ b/drivers/usb/serial/console.c @@ -46,6 +46,8 @@ static struct console usbcons; * ------------------------------------------------------------ */ +static const struct tty_operations usb_console_fake_tty_ops = { +}; /* * The parsing of the command line works exactly like the @@ -137,14 +139,17 @@ static int usb_console_setup(struct console *co, char *options) goto reset_open_count; } kref_init(&tty->kref); - tty_port_tty_set(&port->port, tty); tty->driver = usb_serial_tty_driver; tty->index = co->index; init_ldsem(&tty->ldisc_sem); + INIT_LIST_HEAD(&tty->tty_files); + kref_get(&tty->driver->kref); + tty->ops = &usb_console_fake_tty_ops; if (tty_init_termios(tty)) { retval = -ENOMEM; - goto free_tty; + goto put_tty; } + tty_port_tty_set(&port->port, tty); } /* only call the device specific open if this @@ -162,7 +167,7 @@ static int usb_console_setup(struct console *co, char *options) serial->type->set_termios(tty, port, &dummy); tty_port_tty_set(&port->port, NULL); - kfree(tty); + tty_kref_put(tty); } set_bit(ASYNCB_INITIALIZED, &port->port.flags); } @@ -178,8 +183,8 @@ static int usb_console_setup(struct console *co, char *options) fail: tty_port_tty_set(&port->port, NULL); - free_tty: - kfree(tty); + put_tty: + tty_kref_put(tty); reset_open_count: port->port.count = 0; usb_autopm_put_interface(serial->interface); |