$ id
uid=1001(maxx) gid=1001(maxx) groups=1001(maxx), 5(operator)
$ cc -O -o df5288 df5288.c -pthread && ./df5288
# (no further userspace output: the kernel dies within seconds)
EOF

--- serial console (boot.log), run 1, fresh boot #1 ---
login: Fatal user address access from kernel mode from df5288 at ffffffff80a5438c


Fatal trap 12: page fault while in kernel mode
cpuid = 1; lapic id = 1
fault virtual address	= 0x130
fault code		= supervisor read data, page not present
instruction pointer	= 0x8:0xffffffff80a5438c
stack pointer	        = 0x10:0xfffff80117c1b5f8
frame pointer	        = 0x10:0xfffff80117c1b608
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 0, def32 0, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 931
current thread          = pri 6
kernel: type 12 trap, code=0

CPU1 stopping CPUs: 0x0000003d
 stopped
Stopped at      usbd_transfer_pending+0x3c:     movq    0x130(%rax),%rdi
db>