panic: assertion "(((intptr_t)chunk ^ (intptr_t)z) & ZoneMask) == 0" failed in chunk_mark_allocated at /usr/src/sys/kern/kern_slaballoc.c:1659
cpuid = 1
Trace beginning at frame 0xfffff801179e8208
chunk_mark_allocated() at chunk_mark_allocated+0x8a 0xffffffff80655e4a 
chunk_mark_allocated() at chunk_mark_allocated+0x8a 0xffffffff80655e4a 
_kmalloc() at _kmalloc+0x684 0xffffffff80657444 
ffs_vget() at ffs_vget+0x46 0xffffffff80910766 
vfs_vget() at vfs_vget+0x84 0xffffffff8070db34 
ffs_valloc() at ffs_valloc+0xc5 0xffffffff809057c5 
Debugger("panic")

CPU1 stopping CPUs: 0x0000003d
 stopped
Stopped at      Debugger+0x7c:  movb    $0,0xbdaf09(%rip)
db>