commit 575a5adf48 upstream.
This patch addresses a null-ptr-deref in qt2_process_read_urb() due to
an incorrect bounds check in the following:
if (newport > serial->num_ports) {
dev_err(&port->dev,
"%s - port change to invalid port: %i\n",
__func__, newport);
break;
}
The condition doesn't account for the valid range of the serial->port
buffer, which is from 0 to serial->num_ports - 1. When newport is equal
to serial->num_ports, the assignment of "port" in the
following code is out-of-bounds and NULL:
serial_priv->current_port = newport;
port = serial->port[serial_priv->current_port];
The fix checks if newport is greater than or equal to serial->num_ports
indicating it is out-of-bounds.
Reported-by: syzbot <syzbot+506479ebf12fe435d01a@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=506479ebf12fe435d01a
Fixes: f7a33e608d ("USB: serial: add quatech2 usb to serial driver")
Cc: <stable@vger.kernel.org> # 3.5
Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Qasim Ijaz
6377838560