On 10/24/2017 12:04 AM, Bart Van Assche wrote: > Avoid that submitting an SG_IO ioctl triggers a kernel oops that > is preceded by: > > usercopy: kernel memory overwrite attempt detected to (null) (<null>) (6 bytes) > kernel BUG at mm/usercopy.c:72! > > Additionally, make it easier to diagnose crashes like the one > fixed by this patch. This really should have been two patches... Anyway, applied for 4.14. -- Jens Axboe