[ 127.0971213] panic: kernel diagnostic assertion "mutex_owned(pipe->pipe_lock)" failed: file "/syzkaller/managers/netbsd/kernel/sys/kern/sys_pipe.c", line 371 
[ 127.1104844] cpu0: Begin traceback...
[ 127.1104844] vpanic() at netbsd:vpanic+0x214
[ 127.1171672] _GLOBAL__sub_D_65535_0_cpu_configure() at netbsd:_GLOBAL__sub_D_65535_0_cpu_configure
[ 127.1271905] pipelock() at netbsd:pipelock+0xb0
[ 127.1372112] pipe_write() at netbsd:pipe_write+0x99
[ 127.1482631] do_filewritev() at netbsd:do_filewritev+0x438
[ 127.1572688] sys___syscall() at netbsd:sys___syscall+0xe2
[ 127.1672769] syscall() at netbsd:syscall+0x32e
[ 127.1786185] --- syscall (number 198) ---
[ 127.1873221] 767b7e83f4aa:
[ 127.1873221] cpu0: End traceback...

[ 127.1873221] dumping to dev 4,1 (offset=0, size=0): not possible
[ 127.1873221] 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