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authorJohan Hovold <johan@kernel.org>2019-10-03 15:49:58 +0200
committerJohan Hovold <johan@kernel.org>2019-10-04 10:57:19 +0200
commit7d7e21fafdbc7fcf0854b877bd0975b487ed2717 (patch)
tree05ec67c29029e7ace9d86bbb824537c640c391e5 /drivers
parentdfbac2f4da6a0c4a8f6b4d715a4077a7b8df53ad (diff)
downloadlinux-7d7e21fafdbc7fcf0854b877bd0975b487ed2717.tar.bz2
USB: serial: keyspan: fix NULL-derefs on open() and write()
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/serial/keyspan.c4
1 files changed, 2 insertions, 2 deletions
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";