diff options
| author | Johan Hovold <johan@kernel.org> | 2015-01-05 16:04:13 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-01-29 15:44:39 +0100 |
| commit | 8f3084c44b70ee9e8f5b6bd4816a129bc2646f21 (patch) | |
| tree | c8c4490fea5ff1156e60e218d7de8eaba30f7d34 | |
| parent | 56dfc960370c6b48c69394fa088935a79c7ab3e4 (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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -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 3cf2de433eb8..e4ce48cf7a64 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 @@ -139,15 +141,18 @@ 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; dev_err(&port->dev, "no more memory\n"); - goto free_tty; + goto put_tty; } + tty_port_tty_set(&port->port, tty); } /* only call the device specific open if this @@ -165,7 +170,7 @@ 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); } @@ -181,8 +186,8 @@ 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); |