diff options
| author | Johan Hovold <johan@kernel.org> | 2015-01-05 16:04:13 +0100 |
|---|---|---|
| committer | Zefan Li <lizefan@huawei.com> | 2015-04-14 17:33:52 +0800 |
| commit | 08424459be58c923f13f23a6ba1e605789eec281 (patch) | |
| tree | b7ac615f10bfa47be1055f0e1c883497075f1509 /drivers/usb | |
| parent | 5281ada38d4e35233a43edc782431e1210a03f27 (diff) | |
USB: console: fix potential use after free
commit 32a4bf2e81ec378e5925d4e069e0677a6c86a6ad upstream.
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")
Signed-off-by: Johan Hovold <johan@kernel.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
Diffstat (limited to 'drivers/usb')
| -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 1ee6b2ab0f89..87302ddec0a4 100644 --- a/drivers/usb/serial/console.c +++ b/drivers/usb/serial/console.c @@ -47,6 +47,8 @@ static struct console usbcons; * ------------------------------------------------------------ */ +static const struct tty_operations usb_console_fake_tty_ops = { +}; /* * The parsing of the command line works exactly like the @@ -141,14 +143,17 @@ 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_LIST_HEAD(&tty->tty_files); + kref_get(&tty->driver->kref); + tty->ops = &usb_console_fake_tty_ops; if (tty_init_termios(tty)) { retval = -ENOMEM; err("no more memory"); - goto free_tty; + goto put_tty; } + tty_port_tty_set(&port->port, tty); } /* only call the device specific open if this @@ -170,7 +175,7 @@ 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); } @@ -186,8 +191,8 @@ 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); |