[PATCH 2/3] usb: qcserial avoid pointing to freed memory

Steven Hardy
2011-04-04T17:00:02Z

Rework the qcprobe logic such that serial->private is not set when
qcprobe exits with -ENODEV, otherwise serial->private will point to freed
memory on -ENODEV

Signed-off-by: Steven Hardy <shardy@redhat.com>
---
Repost of qcserial patches posted last week, hopefully addresses review
comments and email-patch-format issues

drivers/usb/serial/qcserial.c | 15 +++++++++------
1 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/serial/qcserial.c b/drivers/usb/serial/qcserial.c
index 6e3b933..cd63864 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 +199,12 @@ 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 if not returning -ENODEV */
+ if (retval != -ENODEV)
+ usb_set_serial_data(serial, data);
return retval;
}

--
1.7.1