From: Johan Hovold <johan@kernel.org>
Date: Sun, 8 May 2016 18:08:03 +0000 (+0200)
Subject: USB: serial: fix minor-number allocation
X-Git-Tag: v4.7-rc1~93^2^2~1
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=194e958c5c3bf4fa0805b0653fe2d0428d3791ff;p=karo-tx-linux.git

USB: serial: fix minor-number allocation

Due to a missing upper bound, invalid minor numbers could be assigned to
ports. Such devices would later fail to register, but let's catch this
early as intended and avoid having devices with only a subset of their
ports registered (potentially the empty set).

Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 7ecf4ff86b9a..4d2b310de55d 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -96,7 +96,8 @@ static int allocate_minors(struct usb_serial *serial, int num_ports)
 	mutex_lock(&table_lock);
 	for (i = 0; i < num_ports; ++i) {
 		port = serial->port[i];
-		minor = idr_alloc(&serial_minors, port, 0, 0, GFP_KERNEL);
+		minor = idr_alloc(&serial_minors, port, 0,
+					USB_SERIAL_TTY_MINORS, GFP_KERNEL);
 		if (minor < 0)
 			goto error;
 		port->minor = minor;