From 1d31a831cc04f5f942de3e7d91edaa52310d3c99 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Wed, 7 Apr 2021 12:23:26 +0200
Subject: [PATCH] tty: amiserial: fix TIOCSSERIAL permission check
Git-commit: 1d31a831cc04f5f942de3e7d91edaa52310d3c99
Patch-mainline: v5.13-rc1
References: git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/tty/amiserial.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index 0c8157fab17f..ec6802ba2bf8 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -970,6 +970,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
 	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))) {
-- 
2.26.2