panic: vm_fault: fault on stack guard, addr: 0xfffff80117a41000
cpuid = 4
Trace beginning at frame 0xfffff801183a8fa8
vm_fault() at vm_fault+0x12eb 0xffffffff8099e6ab 
vm_fault() at vm_fault+0x12eb 0xffffffff8099e6ab 
trap_pfault() at trap_pfault+0x9a 0xffffffff80bd49da 
trap() at trap+0x17c 0xffffffff80bd52dc 
calltrap() at calltrap+0x9 0xffffffff80b9890a 
--- trap 000000000000000c, rip = ffffffff809118f9, rsp = fffff801183a93b0, rbp = fffff801183a96b0 ---
ffs_mount() at ffs_mount+0xab9 0xffffffff809118f9 
vfs_mount() at vfs_mount+0xb0 0xffffffff8070cb80 
Debugger("panic")

CPU4 stopping CPUs: 0x0000002f
 stopped
Stopped at      Debugger+0x7c:  movb    $0,0xbd77f9(%rip)
db> 

[--- ffs_reload (inlined into ffs_mount) maxcluster refill loop at
     ffs_vfsops.c:533-537: adopted fs_ncg=0x20000000 while fs_maxcluster
     array inside fs_csp was sized for ncg=1 (2053-byte kmalloc).
     for (i=0; i<0x20000000; i++) *lp++ = fs_contigsumsize;  writes 2GB
     of stores walking kernel heap until the stack-guard page faults.
     OOB WRITE primitive. ---]