[PATCH 4.4 199/241] USB: rio500: refuse more than one device at a time

From: Greg Kroah-Hartman
Date: Sun Jun 09 2019 - 13:08:59 EST


From: Oliver Neukum <oneukum@xxxxxxxx>

commit 3864d33943b4a76c6e64616280e98d2410b1190f upstream.

This driver is using a global variable. It cannot handle more than
one device at a time. The issue has been existing since the dawn
of the driver.

Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
Reported-by: syzbot+35f04d136fc975a70da4@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/misc/rio500.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)

--- a/drivers/usb/misc/rio500.c
+++ b/drivers/usb/misc/rio500.c
@@ -464,15 +464,23 @@ static int probe_rio(struct usb_interfac
{
struct usb_device *dev = interface_to_usbdev(intf);
struct rio_usb_data *rio = &rio_instance;
- int retval;
+ int retval = 0;

- dev_info(&intf->dev, "USB Rio found at address %d\n", dev->devnum);
+ mutex_lock(&rio500_mutex);
+ if (rio->present) {
+ dev_info(&intf->dev, "Second USB Rio at address %d refused\n", dev->devnum);
+ retval = -EBUSY;
+ goto bail_out;
+ } else {
+ dev_info(&intf->dev, "USB Rio found at address %d\n", dev->devnum);
+ }

retval = usb_register_dev(intf, &usb_rio_class);
if (retval) {
dev_err(&dev->dev,
"Not able to get a minor for this device.\n");
- return -ENOMEM;
+ retval = -ENOMEM;
+ goto bail_out;
}

rio->rio_dev = dev;
@@ -481,7 +489,8 @@ static int probe_rio(struct usb_interfac
dev_err(&dev->dev,
"probe_rio: Not enough memory for the output buffer\n");
usb_deregister_dev(intf, &usb_rio_class);
- return -ENOMEM;
+ retval = -ENOMEM;
+ goto bail_out;
}
dev_dbg(&intf->dev, "obuf address:%p\n", rio->obuf);

@@ -490,7 +499,8 @@ static int probe_rio(struct usb_interfac
"probe_rio: Not enough memory for the input buffer\n");
usb_deregister_dev(intf, &usb_rio_class);
kfree(rio->obuf);
- return -ENOMEM;
+ retval = -ENOMEM;
+ goto bail_out;
}
dev_dbg(&intf->dev, "ibuf address:%p\n", rio->ibuf);

@@ -498,8 +508,10 @@ static int probe_rio(struct usb_interfac

usb_set_intfdata (intf, rio);
rio->present = 1;
+bail_out:
+ mutex_unlock(&rio500_mutex);

- return 0;
+ return retval;
}

static void disconnect_rio(struct usb_interface *intf)