Fatal trap 9: general protection fault while in kernel mode
cpuid = 1; apic id = 01
instruction pointer	= 0x20:0xffffffff811640c5
stack pointer	        = 0x28:0xfffffe0020db6610
frame pointer	        = 0x28:0xfffffe0020db6650
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		= 1435 (syz-executor0783814)
trap number		= 9
panic: general protection fault
cpuid = 1
time = 1553926097
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe0020db62e0
vpanic() at vpanic+0x1e0/frame 0xfffffe0020db6340
panic() at panic+0x43/frame 0xfffffe0020db63a0
trap_fatal() at trap_fatal+0x4c6/frame 0xfffffe0020db6420
trap() at trap+0xba/frame 0xfffffe0020db6540
calltrap() at calltrap+0x8/frame 0xfffffe0020db6540
--- trap 0x9, rip = 0xffffffff811640c5, rsp = 0xfffffe0020db6610, rbp = 0xfffffe0020db6650 ---
unp_dispose() at unp_dispose+0xa5/frame 0xfffffe0020db6650
sofree() at sofree+0x42c/frame 0xfffffe0020db66b0
soclose() at soclose+0x5b3/frame 0xfffffe0020db6730
_fdrop() at _fdrop+0x3a/frame 0xfffffe0020db6760
closef() at closef+0x27d/frame 0xfffffe0020db67f0
fdescfree_fds() at fdescfree_fds+0xbd/frame 0xfffffe0020db6840
fdescfree() at fdescfree+0x58a/frame 0xfffffe0020db6900
exit1() at exit1+0x780/frame 0xfffffe0020db6970
sys_sys_exit() at sys_sys_exit+0xd/frame 0xfffffe0020db6980
amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe0020db6ab0
fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe0020db6ab0
--- syscall (1, FreeBSD ELF64, sys_sys_exit), rip = 0x4478ba, rsp = 0x7fffffffea68, rbp = 0x7fffffffea80 ---
KDB: enter: panic
[ thread pid 1435 tid 100079 ]
Stopped at      kdb_enter+0x6a: movq    $0,kdb_why