Changing the port close-delay parameter is a privileged operation so make sure to return -EPERM if a regular user tries to change it.
Fixes: 7355ba3445f2 ("staging: fwserial: Add TTY-over-Firewire serial driver") Cc: stable@vger.kernel.org # 3.8 Signed-off-by: Johan Hovold johan@kernel.org --- drivers/staging/fwserial/fwserial.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/fwserial/fwserial.c b/drivers/staging/fwserial/fwserial.c index c963848522b1..440d11423812 100644 --- a/drivers/staging/fwserial/fwserial.c +++ b/drivers/staging/fwserial/fwserial.c @@ -1232,20 +1232,24 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) { struct fwtty_port *port = tty->driver_data; + unsigned int cdelay;
if (ss->irq != 0 || ss->port != 0 || ss->custom_divisor != 0 || ss->baud_base != 400000000) return -EPERM;
+ cdelay = msecs_to_jiffies(ss->close_delay * 10); + mutex_lock(&port->port.mutex); if (!capable(CAP_SYS_ADMIN)) { - if (((ss->flags & ~ASYNC_USR_MASK) != + if (cdelay != port->port.close_delay || + ((ss->flags & ~ASYNC_USR_MASK) != (port->port.flags & ~ASYNC_USR_MASK))) { mutex_unlock(&port->port.mutex); return -EPERM; } } - port->port.close_delay = msecs_to_jiffies(ss->close_delay * 10); + port->port.close_delay = cdelay; mutex_unlock(&port->port.mutex);
return 0;