Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 01
fault virtual address	= 0x0
fault code		= supervisor read data, page not present
instruction pointer	= 0x20:0xffffffff8148a28c
stack pointer	        = 0x28:0xfffffe0056d47ea0
kbd1 at kbdmux0
frame pointer	        = 0x28:0xfffffe0056d47ed0
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags	= resume, IOPL = 0
current process		= 13 (g_event)
rdi: 0000000000000000 rsi: 000000000a860581 rdx: fffff78000000000
rcx: 0000000000000074  r8: 0000000000000000  r9: 0000000000000000
rax: fffffe00033eee30 rbx: 0000000000000000 rbp: fffffe0056d47ed0
r10: 0000000000000000 r11: 0000000000000017 r12: 0000000000000000
r13: 0000000000000074 r14: ffffffff82694380 r15: fffffe0054302740
trap number		= 12
panic: page fault
cpuid = 1
time = 1
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0xc6/frame 0xfffffe0056d475d0
kdb_backtrace() at kdb_backtrace+0xd0/frame 0xfffffe0056d47730
vpanic() at vpanic+0x26a/frame 0xfffffe0056d478f0
panic() at panic+0xb5/frame 0xfffffe0056d479b0
trap_fatal() at trap_fatal+0x7f2/frame 0xfffffe0056d47ad0
trap_pfault() at trap_pfault+0x179/frame 0xfffffe0056d47bf0
trap() at trap+0x648/frame 0xfffffe0056d47dd0
calltrap() at calltrap+0x8/frame 0xfffffe0056d47dd0
--- trap 0xc, rip = 0xffffffff8148a28c, rsp = 0xfffffe0056d47ea0, rbp = 0xfffffe0056d47ed0 ---
_thread_lock() at _thread_lock+0x5c/frame 0xfffffe0056d47ed0
g_event_procbody() at g_event_procbody+0x25/frame 0xfffffe0056d47ef0
fork_exit() at fork_exit+0xcc/frame 0xfffffe0056d47f30
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0056d47f30
--- trap 0, rip = 0, rsp = 0, rbp = 0 ---
KDB: enter: panic
[ thread pid 13 tid 100035 ]
Stopped at      kdb_enter+0x6e: movq    $0,0x23cd1b7(%rip)
db> serialport: Connected to syzkaller.us-central1-b.ci-freebsd-main-test-1 port 1 (session ID: 491e62f0e71f2e26e92e02fcad3184242279370653ae184db9b472f0d4a2489d, active connections: 1).