diff options
| author | Johan Hovold <johan@kernel.org> | 2021-04-07 13:23:32 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-04-07 18:22:07 +0300 |
| commit | b91cfb2573aeb5ab426fc3c35bcfe9e0d2a7ecbc (patch) | |
| tree | de429538ba2ccfcaf6dcf262356ba186a52d89ec | |
| parent | be6cf583d24dfe87324dd2830d90fc056e0a6648 (diff) | |
| download | linux-b91cfb2573aeb5ab426fc3c35bcfe9e0d2a7ecbc.tar.xz | |
tty: mxser: fix TIOCSSERIAL permission check
Changing the port type and closing_wait parameter are privileged
operations so make sure to return -EPERM if a regular user tries to
change them.
Note that the closing_wait parameter would not actually have been
changed but the return value did not indicate that.
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-15-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/mxser.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c index 914b23071961..2d8e76263a25 100644 --- a/drivers/tty/mxser.c +++ b/drivers/tty/mxser.c @@ -1270,6 +1270,7 @@ static int mxser_set_serial_info(struct tty_struct *tty, if (!capable(CAP_SYS_ADMIN)) { if ((ss->baud_base != info->baud_base) || (close_delay != info->port.close_delay) || + (closing_wait != info->port.closing_wait) || ((ss->flags & ~ASYNC_USR_MASK) != (info->port.flags & ~ASYNC_USR_MASK))) { mutex_unlock(&port->mutex); return -EPERM; @@ -1296,11 +1297,11 @@ static int mxser_set_serial_info(struct tty_struct *tty, baud = ss->baud_base / ss->custom_divisor; tty_encode_baud_rate(tty, baud, baud); } - } - info->type = ss->type; + info->type = ss->type; - process_txrx_fifo(info); + process_txrx_fifo(info); + } if (tty_port_initialized(port)) { if (flags != (port->flags & ASYNC_SPD_MASK)) { |