Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 01
fault virtual address	= 0x418
fault code		= supervisor read data, page not present
instruction pointer	= 0x20:0xffffffff810532e8
stack pointer	        = 0x28:0xfffffe001f6e5650
frame pointer	        = 0x28:0xfffffe001f6e5700
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 901 (syz-executor.0)
trap number		= 12
panic: page fault
cpuid = 1
time = 1560115846
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe001f6e52b0
vpanic() at vpanic+0x1e0/frame 0xfffffe001f6e5310
panic() at panic+0x43/frame 0xfffffe001f6e5370
trap_fatal() at trap_fatal+0x4de/frame 0xfffffe001f6e53f0
trap_pfault() at trap_pfault+0x9f/frame 0xfffffe001f6e5460
trap() at trap+0x44d/frame 0xfffffe001f6e5580
calltrap() at calltrap+0x8/frame 0xfffffe001f6e5580
--- trap 0xc, rip = 0xffffffff810532e8, rsp = 0xfffffe001f6e5650, rbp = 0xfffffe001f6e5700 ---
_sx_xlock_hard() at _sx_xlock_hard+0x2f8/frame 0xfffffe001f6e5700
_sx_xlock() at _sx_xlock+0x136/frame 0xfffffe001f6e5750
soreceive_generic() at soreceive_generic+0x1a2/frame 0xfffffe001f6e5810
soreceive() at soreceive+0xb9/frame 0xfffffe001f6e5870
dofileread() at dofileread+0xd3/frame 0xfffffe001f6e58d0
kern_readv() at kern_readv+0x66/frame 0xfffffe001f6e5910
sys_read() at sys_read+0xd2/frame 0xfffffe001f6e5980
amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe001f6e5ab0
fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe001f6e5ab0
--- syscall (198, FreeBSD ELF64, nosys), rip = 0x4131ba, rsp = 0x7fffdfffdf38, rbp = 0x3 ---
KDB: enter: panic
[ thread pid 901 tid 100238 ]
Stopped at      kdb_enter+0x6a: movq    $0,kdb_why