[ 486.6543620] panic: kernel diagnostic assertion "c->c_cpu->cc_lwp == curlwp || c->c_cpu->cc_active != c" failed: file "/syzkaller/managers/netbsd/kernel/sys/kern/kern_timeout.c", line 318 
[ 486.6746573] cpu0: Begin traceback...
[ 486.6787985] vpanic() at netbsd:vpanic+0x214
[ 486.6877852] _GLOBAL__sub_D_65535_0_cpu_configure() at netbsd:_GLOBAL__sub_D_65535_0_cpu_configure
[ 486.7100713] callout_destroy() at netbsd:callout_destroy+0xcb
[ 486.7212044] itimerfree() at netbsd:itimerfree+0x102
[ 486.7326041] timers_free() at netbsd:timers_free+0x2ef
[ 486.7439547] exit1() at netbsd:exit1+0x28f
[ 486.7548539] sigexit() at netbsd:sigexit+0x33c
[ 486.7657656] sendsig() at netbsd:sendsig
[ 486.7769075] lwp_userret() at netbsd:lwp_userret+0x2db
[ 486.7880489] syscall() at netbsd:syscall+0x413
[ 486.7995267] --- syscall (number 4) ---
[ 486.7995267] 7c0e5a63f4aa:
[ 486.7995267] cpu0: End traceback...

[ 486.8132998] dumping to dev 4,1 (offset=0, size=0): not possible
[ 486.8132998] 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