From: Johan Hovold <johan@kernel.org>
Date: Wed, 7 Apr 2021 10:39:15 +0000 (+0200)
Subject: USB: serial: ti_usb_3410_5052: fix TIOCSSERIAL permission check
X-Git-Tag: v5.15.73~12144^2~20^2~44
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d370c90dcd64e427a79a093a070117a1571d4cd8;p=platform%2Fkernel%2Flinux-rpi.git

USB: serial: ti_usb_3410_5052: fix TIOCSSERIAL permission check

Changing the port closing-wait parameter is a privileged operation so
make sure to return -EPERM if a regular user tries to change it.

Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
---

diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c
index 4b497c1e850b..bb50098a0ce6 100644
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -1418,14 +1418,19 @@ static int ti_set_serial_info(struct tty_struct *tty,
 	struct serial_struct *ss)
 {
 	struct usb_serial_port *port = tty->driver_data;
-	struct ti_port *tport = usb_get_serial_port_data(port);
+	struct tty_port *tport = &port->port;
 	unsigned cwait;
 
 	cwait = ss->closing_wait;
 	if (cwait != ASYNC_CLOSING_WAIT_NONE)
 		cwait = msecs_to_jiffies(10 * ss->closing_wait);
 
-	tport->tp_port->port.closing_wait = cwait;
+	if (!capable(CAP_SYS_ADMIN)) {
+		if (cwait != tport->closing_wait)
+			return -EPERM;
+	}
+
+	tport->closing_wait = cwait;
 
 	return 0;
 }