staging: android: vsoc: fix copy_from_user overrun

The `np->permission' structure is smaller than the `np' structure but
sizeof(*np) worth of data is copied in there. Fix the size passed to
copy_from_user() to avoid overrun.

Fixes: 3d2ec9dc ("staging: Android: Add 'vsoc' driver for cuttlefish.")
Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/vsoc.c

@@ -259,7 +259,8 @@ do_create_fd_scoped_permission(struct vsoc_device_region *region_p,
 	atomic_t *owner_ptr = NULL;
 	struct vsoc_device_region *managed_region_p;
 
-	if (copy_from_user(&np->permission, &arg->perm, sizeof(*np)) ||
+	if (copy_from_user(&np->permission,
+			   &arg->perm, sizeof(np->permission)) ||
 	    copy_from_user(&managed_fd,
 			   &arg->managed_region_fd, sizeof(managed_fd))) {
 		return -EFAULT;