[ 3619.7375807] panic: kernel diagnostic assertion "pmap->pm_obj[i].uo_npages == 0" failed: file "/syzkaller/managers/netbsd/kernel/sys/arch/x86/x86/pmap.c", line 2464 
[ 3619.7563484] cpu0: Begin traceback...
[ 3619.7605807] vpanic() at netbsd:vpanic+0x214
[ 3619.7718460] _GLOBAL__sub_D_65535_0_cpu_configure() at netbsd:_GLOBAL__sub_D_65535_0_cpu_configure
[ 3619.7932195] pmap_destroy() at netbsd:pmap_destroy+0x40d
[ 3619.8043518] pmap_pp_remove() at netbsd:pmap_pp_remove+0x876
[ 3619.8154773] uvm_anon_dispose() at netbsd:uvm_anon_dispose+0x179
[ 3619.8266063] uvm_anon_freelst() at netbsd:uvm_anon_freelst+0x48
[ 3619.8381090] amap_wipeout() at netbsd:amap_wipeout+0x237
[ 3619.8500752] uvm_unmap_detach() at netbsd:uvm_unmap_detach+0x8b
[ 3619.8711200] uvmspace_free() at netbsd:uvmspace_free+0x200
[ 3619.8822497] exit1() at netbsd:exit1+0x39d
[ 3619.8933784] sys_exit() at netbsd:sys_exit+0x6c
[ 3619.9045085] syscall() at netbsd:syscall+0x32e
[ 3619.9045085] --- syscall (number 1) ---
[ 3619.9171502] 7f1f9fafe47a:
[ 3619.9171502] cpu0: End traceback...

[ 3619.9171502] dumping to dev 4,1 (offset=0, size=0): not possible
[ 3619.9171502] rebooting...
SeaBIOS (version 1.8.2-20190122_225043-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