kern.securelevel: 0 -> 1
creating runtime link editor directory cache.
preserving editor files.
starting network daemons: sshd.
starting local daemons:.
Fri Jan 25 04:38:45 PST 2019

OpenBSD/amd64 (ci-openbsd-multicore-9.c.syzkaller.internal) (tty00)

Warning: Permanently added '10.128.0.152' (ECDSA) to the list of known hosts.
2019/01/25 04:39:10 parsed 1 programs
2019/01/25 04:39:15 executed programs: 0
login: userret: returning with the following locks held:

exclusive rrwlock inode r = 0 (0xfffffd806afb83d8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547

panic: witness_warn

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

    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND

*188618  48414      0           0  0x4000000    0  syz-executor1

 145454  92932      0         0x2      0x480    1  syz-executor1

db_enter() at db_enter+0x18

panic() at panic+0x16c

witness_warn(6b9544808654530a,0,ffff800020bbabd0) at witness_warn+0x6e0

userret(f1e6ee0f51a7a44b) at userret+0x361

syscall(1607104c276985fb) at syscall+0x680

Xsyscall(6,5,c,0,3,bd2423490d8) at Xsyscall+0x128

end of kernel

end trace frame: 0xbd4b53d1d10, count: 9

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

witness_warn

ddb{0}> trace

db_enter() at db_enter+0x18

panic() at panic+0x16c

witness_warn(6b9544808654530a,0,ffff800020bbabd0) at witness_warn+0x6e0

userret(f1e6ee0f51a7a44b) at userret+0x361

syscall(1607104c276985fb) at syscall+0x680

Xsyscall(6,5,c,0,3,bd2423490d8) at Xsyscall+0x128

end of kernel

end trace frame: 0xbd4b53d1d10, count: -6

ddb{0}> show registers

rdi                                0

rsi                              0x1

rbp               0xffff800020c8bba0

rbx               0xffff800020c8bc40

rdx               0xffffffff81f2ea76    apollo_pio_rec+0x9bcf

rcx                            0x201

rax                              0x1

r8                0xffffffff810e4f24    kprintf+0x174

r9                               0x1

r10                0x2925f90960a5133

r11               0xde023a2762b06d5a

r12                     0x3000000008

r13               0xffff800020c8bbb0

r14                            0x100

r15                              0x1

rip               0xffffffff8171e6c8    db_enter+0x18

cs                               0x8

rflags                         0x246

rsp               0xffff800020c8bb90

ss                              0x10

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

ddb{0}> show proc

PROC (syz-executor1) pid=188618 stat=onproc

    flags process=0 proc=4000000<THREAD>

    pri=32, usrpri=52, nice=20

    forw=0xffffffffffffffff, list=0xffff800020bba978,0xffff800020bbb798

    process=0xffff800020b953c0 user=0xffff800020c86000, vmspace=0xfffffd807f00db40

    estcpu=36, cpticks=2, pctcpu=0.0

    user=0, sys=2, intr=0

ddb{0}>