| From 02259c824db47d4ea96b80f628695442ec45e71b Mon Sep 17 00:00:00 2001 |
| From: Johan Hovold <johan@kernel.org> |
| Date: Thu, 3 Oct 2019 15:49:58 +0200 |
| Subject: [PATCH] USB: serial: keyspan: fix NULL-derefs on open() and write() |
| |
| commit 7d7e21fafdbc7fcf0854b877bd0975b487ed2717 upstream. |
| |
| Fix NULL-pointer dereferences on open() and write() which can be |
| triggered by a malicious USB device. |
| |
| The current URB allocation helper would fail to initialise the newly |
| allocated URB if the device has unexpected endpoint descriptors, |
| something which could lead NULL-pointer dereferences in a number of |
| open() and write() paths when accessing the URB. For example: |
| |
| BUG: kernel NULL pointer dereference, address: 0000000000000000 |
| ... |
| RIP: 0010:usb_clear_halt+0x11/0xc0 |
| ... |
| Call Trace: |
| ? tty_port_open+0x4d/0xd0 |
| keyspan_open+0x70/0x160 [keyspan] |
| serial_port_activate+0x5b/0x80 [usbserial] |
| tty_port_open+0x7b/0xd0 |
| ? check_tty_count+0x43/0xa0 |
| tty_open+0xf1/0x490 |
| |
| BUG: kernel NULL pointer dereference, address: 0000000000000000 |
| ... |
| RIP: 0010:keyspan_write+0x14e/0x1f3 [keyspan] |
| ... |
| Call Trace: |
| serial_write+0x43/0xa0 [usbserial] |
| n_tty_write+0x1af/0x4f0 |
| ? do_wait_intr_irq+0x80/0x80 |
| ? process_echoes+0x60/0x60 |
| tty_write+0x13f/0x2f0 |
| |
| BUG: kernel NULL pointer dereference, address: 0000000000000000 |
| ... |
| RIP: 0010:keyspan_usa26_send_setup+0x298/0x305 [keyspan] |
| ... |
| Call Trace: |
| keyspan_open+0x10f/0x160 [keyspan] |
| serial_port_activate+0x5b/0x80 [usbserial] |
| tty_port_open+0x7b/0xd0 |
| ? check_tty_count+0x43/0xa0 |
| tty_open+0xf1/0x490 |
| |
| Fixes: fdcba53e2d58 ("fix for bugzilla #7544 (keyspan USB-to-serial converter)") |
| Cc: stable <stable@vger.kernel.org> # 2.6.21 |
| Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Johan Hovold <johan@kernel.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/usb/serial/keyspan.c b/drivers/usb/serial/keyspan.c |
| index d34779fe4a8d..e66a59ef43a1 100644 |
| --- a/drivers/usb/serial/keyspan.c |
| +++ b/drivers/usb/serial/keyspan.c |
| @@ -1741,8 +1741,8 @@ static struct urb *keyspan_setup_urb(struct usb_serial *serial, int endpoint, |
| |
| ep_desc = find_ep(serial, endpoint); |
| if (!ep_desc) { |
| - /* leak the urb, something's wrong and the callers don't care */ |
| - return urb; |
| + usb_free_urb(urb); |
| + return NULL; |
| } |
| if (usb_endpoint_xfer_int(ep_desc)) { |
| ep_type_name = "INT"; |
| -- |
| 2.7.4 |
| |