[PATCH 5.11 008/601] tty: amiserial: fix TIOCSSERIAL permission check

Greg Kroah-Hartman
2021-05-12T16:52:46Z

From: Johan Hovold <johan@kernel.org>

commit 1d31a831cc04f5f942de3e7d91edaa52310d3c99 upstream.

Changing the port closing_wait parameter is a privileged operation.

Add the missing check to TIOCSSERIAL so that -EPERM is returned in case
an unprivileged user tries to change the closing-wait setting.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-9-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/tty/amiserial.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -970,6 +970,7 @@ static int set_serial_info(struct tty_st
if (!serial_isroot()) {
if ((ss->baud_base != state->baud_base) ||
(ss->close_delay != port->close_delay) ||
+ (ss->closing_wait != port->closing_wait) ||
(ss->xmit_fifo_size != state->xmit_fifo_size) ||
((ss->flags & ~ASYNC_USR_MASK) !=
(port->flags & ~ASYNC_USR_MASK))) {