V26[9] str=[16 x A] at 0xfffff80118540ff0, str[16] lands on UNMAPPED page 0xfffff80118541000; calling kstrndup(str, maxlen=16)
Fatal trap 12: page fault while in kernel mode
kernel: type 12 trap, code=0
Stopped at      memcpy+0x61:    movq    -0x8(%rsi,%rcx,1),%r10
(bcopy inside kstrndup reading str[maxlen] - the byte past the maxlen-bounded
 region - on the guard page)