kern.securelevel: 0 -> 1
creating runtime link editor directory cache.
preserving editor files.
starting network daemons: sshd.
starting local daemons:.
Mon Jan 28 04:45:02 PST 2019

OpenBSD/amd64 (ci-openbsd-multicore-7.c.syzkaller.internal) (tty00)

Warning: Permanently added '10.128.0.105' (ECDSA) to the list of known hosts.
2019/01/28 04:45:54 parsed 1 programs
2019/01/28 04:46:00 executed programs: 0
login: witness: thread 0xffff800020bba720 exiting with the following locks held:

exclusive rrwlock inode r = 0 (0xfffffd807b3b25f8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547

panic: thread 0xffff800020bba720 cannot exit while holding sleeplocks

Stopped at      db_enter+0x18:  addq    $0x8,%rsp

    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND

 128343  76038      0         0x2      0x480    1  syz-executor1

*215594  31246      0     0x14000      0x200    0  reaper

db_enter() at db_enter+0x18

panic() at panic+0x16c

witness_thread_exit(6731aca14bc2ea81) at witness_thread_exit+0x244

reaper(0) at reaper+0x14f

end trace frame: 0x0, count: 11

https://www.openbsd.org/ddb.html describes the minimum info required in bug

reports.  Insufficient info makes it difficult to find and fix bugs.

ddb{0}> 

ddb{0}> set $lines = 0

ddb{0}> show panic

thread 0xffff800020bba720 cannot exit while holding sleeplocks

ddb{0}> trace

db_enter() at db_enter+0x18

panic() at panic+0x16c

witness_thread_exit(6731aca14bc2ea81) at witness_thread_exit+0x244

reaper(0) at reaper+0x14f

end trace frame: 0x0, count: -4

ddb{0}> show registers

rdi                                0

rsi                              0x1

rbp               0xffff800020b66e30

rbx               0xffff800020b66ed0

rdx               0xffffffff81f3066d    apollo_pio_rec+0x86ea

rcx                            0x201

rax                              0x1

r8                0xffffffff817c1934    kprintf+0x174

r9                               0x1

r10               0x277c8f88204e0c38

r11               0xbd293342174a2262

r12                     0x3000000008

r13               0xffff800020b66e40

r14                            0x100

r15                              0x1

rip               0xffffffff81598c38    db_enter+0x18

cs                               0x8

rflags                         0x246

rsp               0xffff800020b66e20

ss                              0x10

db_enter+0x18:  addq    $0x8,%rsp

ddb{0}> show proc

PROC (reaper) pid=215594 stat=onproc

    flags process=14000<NOZOMBIE,SYSTEM> proc=200<SYSTEM>

    pri=4, usrpri=51, nice=20

    forw=0xffffffffffffffff, list=0xffff800020b20e10,0xffff800020b21c30

    process=0xffff800020b5a698 user=0xffff800020b62000, vmspace=0xffffffff822f1200

    estcpu=1, cpticks=3, pctcpu=0.0

    user=0, sys=3, intr=0

ddb{0}>