usbdevfs: Correct amount of data copied to user in processcompl_compat
Hans de Goede [Wed, 4 Jul 2012 07:18:01 +0000 (09:18 +0200)]
commit 2102e06a5f2e414694921f23591f072a5ba7db9f upstream.

iso data buffers may have holes in them if some packets were short, so for
iso urbs we should always copy the entire buffer, just like the regular
processcompl does.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/devio.c

index 4e57772..404413b 100644 (file)
@@ -1615,10 +1615,14 @@ static int processcompl_compat(struct async *as, void __user * __user *arg)
        void __user *addr = as->userurb;
        unsigned int i;
 
-       if (as->userbuffer && urb->actual_length)
-               if (copy_to_user(as->userbuffer, urb->transfer_buffer,
-                                urb->actual_length))
+       if (as->userbuffer && urb->actual_length) {
+               if (urb->number_of_packets > 0)         /* Isochronous */
+                       i = urb->transfer_buffer_length;
+               else                                    /* Non-Isoc */
+                       i = urb->actual_length;
+               if (copy_to_user(as->userbuffer, urb->transfer_buffer, i))
                        return -EFAULT;
+       }
        if (put_user(as->status, &userurb->status))
                return -EFAULT;
        if (put_user(urb->actual_length, &userurb->actual_length))