diff options
| author | Johan Hovold <johan@kernel.org> | 2021-04-07 12:23:20 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-04-07 17:22:06 +0200 |
| commit | 2104eb283df66a482b60254299acbe3c68c03412 (patch) | |
| tree | 4f50eaff4ae772cf74866e06f615e8b94c58f3ad /drivers/staging/fwserial | |
| parent | 7a3791afdbd5a951b09a7689bba856bd9f6c6a9f (diff) | |
| download | linux-2104eb283df66a482b60254299acbe3c68c03412.tar.bz2 | |
staging: fwserial: fix TIOCSSERIAL permission check
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>
Link: https://lore.kernel.org/r/20210407102334.32361-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/fwserial')
| -rw-r--r-- | drivers/staging/fwserial/fwserial.c | 8 |
1 files 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; |