[ 471.4822496] panic: kernel diagnostic assertion "kn->kn_fop != NULL" failed: file "/syzkaller/managers/netbsd/kernel/sys/kern/kern_event.c", line 1653 
[[  447711..44997766558855]]  cWpAuRN0:IN GB:e gSinP L tNraOcTe LbaOcWkER.E..D[
 471.4976585]  ON SYSCALL 0 36811000 EXIT 231b000 7
[ 471.[ 49477615.48957] 65WA8R5N] INvGp:a niScP(L) N OaTt  LOWERED OnNe tbSsYdS:CAvLpLa n0i c+-102x221246
7[
 471.4976585] 36 EXIT 44e106b0 7
[ 471.4976585] _GLOBAL__sub_D_65535_0_cpu_configure() at netbsd:_GLOBAL__sub_D_65535_0_cpu_configure
[ 471.4976585] knote() at netbsd:knote+0x117
[ 471.4976585] selnotify() at netbsd:selnotify+0x30
[ 471.4976585] pipeselwakeup() at netbsd:pipeselwakeup+0x47
[ 471.4976585] pipeclose.part.0() at netbsd:pipeclose.part.0+0x8a
[ 471.4976585] pipe_close() at netbsd:pipe_close+0x2b
[ 471.4976585] closef() at netbsd:closef+0xf3
[ 471.4976585] fd_free() at netbsd:fd_free+0x174
[ 471.4976585] exit1() at netbsd:exit1+0x265
[ 471.4976585] sigexit() at netbsd:sigexit+0x33c
[ 471.4976585] sendsig() at netbsd:sendsig
[ 471.4976585] lwp_userret() at netbsd:lwp_userret+0x2db
[ 471.4976585] syscall() at netbsd:syscall+0x42d
[ 471.4976585] --- syscall (number 32) ---
[ 471.4976585] 748f06a3e02a:
[ 471.4976585] cpu0: End traceback...

[ 471.4976585] dumping to dev 4,1 (offset=0, size=0): not possible
[ 471.4976585] rebooting...
SeaBIOS (version 1.8.2-20190322_093631-google)
Total RAM Size = 0x00000001e0000000 = 7680 MiB
CPUs found: 2     Max CPUs supported: 2
found virtio-scsi at 0:3
virtio-scsi vendor='Google' product='PersistentDisk' rev='1' type=0 removable=0
virtio-scsi blksize=512 sectors=4194304 = 2048 MiB
drive 0x000f29c0: PCHS=0/0/0 translation=lba LCHS=520/128/63 s=4194304
Booting from Hard Disk 0...

>> NetBSD/x86 BIOS Boot, Revision 5.10 (Tue Jul 17 14:59:51 UTC 2018) (from NetBSD 8.0)
>> Memory: 639/3144640 k

     1. Boot normally
     2. Boot single user
     3. Disable ACPI
     4. Disable ACPI and SMP
     5. Drop to boot prompt