[GIT PATCH 2/3] Resend : Fix memory leak in qcserial driver

Steven Hardy
2011-03-28T17:38:59Z

Patch 2 of 3, addresses the problem where serial->private can end up pointing to freed memory in the event qcprobe fails & returns -ENODEV

Original description:
3 - Don't assign serial->private when doing the kzalloc or serial->private ends up pointing to freed memory in the event we return -ENODEV, instead call usb_set_serial_data(serial, data) at the end of the function, and only have one return-point.

Signed-off-by: Steve Hardy <shardy@redhat.com>

diff --git a/drivers/usb/serial/qcserial.c b/drivers/usb/serial/qcserial.c
index 6e3b933..0463dab 100644
--- a/drivers/usb/serial/qcserial.c
+++ b/drivers/usb/serial/qcserial.c
@@ -111,7 +111,7 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
ifnum = intf->desc.bInterfaceNumber;
dbg("This Interface = %d", ifnum);

- data = serial->private = kzalloc(sizeof(struct usb_wwan_intf_private),
+ data = kzalloc(sizeof(struct usb_wwan_intf_private),
GFP_KERNEL);
if (!data)
return -ENOMEM;
@@ -134,8 +134,10 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
usb_endpoint_is_bulk_out(&intf->endpoint[1].desc)) {
dbg("QDL port found");

- if (serial->interface->num_altsetting == 1)
- return 0;
+ if (serial->interface->num_altsetting == 1) {
+ retval = 0; /* Success */
+ break;
+ }

retval = usb_set_interface(serial->dev, ifnum, 1);
if (retval < 0) {
@@ -145,7 +147,6 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
retval = -ENODEV;
kfree(data);
}
- return retval;
}
break;

@@ -177,7 +178,6 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
retval = -ENODEV;
kfree(data);
}
- return retval;
} else if (ifnum==3) {
/*
* NMEA (serial line 9600 8N1)
@@ -199,9 +199,11 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
dev_err(&serial->dev->dev,
"unknown number of interfaces: %d\n", nintf);
kfree(data);
- return -ENODEV;
+ retval = -ENODEV;
}

+ /* Set serial->private may be null if -ENODEV */
+ usb_set_serial_data(serial, data);
return retval;
}