Hi Mathieu, On (10/16/18 15:17), Mathieu Desnoyers wrote: > > Therefore, only an internal kernel bug between vm_map_user_ram() and > vm_unmap_user_ram() should trigger the BUG_ON(). No user input is passed > to vm_unmap_user_ram(). > > Now, let's look at vm_map_user_ram(). It calls alloc_vmap_area(), which returns > a vmap_area. Then if vmap_page_range failed, vm_unmap_user_ram is called on the > memory that has just been returned by vm_map_user_ram. Again, only an internal > bug between map/unmap can trigger the BUG_ON() in vm_unmap_user_ram. Thanks for spending time on this. Just wanted someone to have extra look at syscall->BUG_ON(). -ss
