kern.securelevel: 0 -> 1
creating runtime link editor directory cache.
preserving editor files.
starting network daemons: sshd.
starting local daemons:.
Thu Jan 24 19:39:09 PST 2019

OpenBSD/amd64 (ci-openbsd-multicore-5.c.syzkaller.internal) (tty00)

Warning: Permanently added '10.128.0.85' (ECDSA) to the list of known hosts.
2019/01/24 19:39:31 parsed 1 programs
2019/01/24 19:39:36 executed programs: 0
login: userret: returning with the following locks held:

exclusive rrwlock inode r = 0 (0xfffffd806d380708) 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

*125966  98055      0      0x1000  0x4080000    0  syz-executor1

 273298  27250     73    0x100010          0    1K syslogd

db_enter() at db_enter+0x18

panic() at panic+0x16c

witness_warn(b6380006ff745033,0,ffff800020bba270) at witness_warn+0x6e0

userret(d6813d5fa775f93f) at userret+0x361

syscall(fd657b6d84a36906) at syscall+0x680

Xsyscall(6,5,c,0,3,b2c9870b010) at Xsyscall+0x128

end of kernel

end trace frame: 0xb2f096b0280, 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(b6380006ff745033,0,ffff800020bba270) at witness_warn+0x6e0

userret(d6813d5fa775f93f) at userret+0x361

syscall(fd657b6d84a36906) at syscall+0x680

Xsyscall(6,5,c,0,3,b2c9870b010) at Xsyscall+0x128

end of kernel

end trace frame: 0xb2f096b0280, count: -6

ddb{0}> show registers

rdi                                0

rsi                              0x1

rbp               0xffff800020c77260

rbx               0xffff800020c77300

rdx               0xffffffff81f2ec1b    cy_pio_rec+0x1a98

rcx                            0x201

rax                              0x1

r8                0xffffffff817cef24    kprintf+0x174

r9                               0x1

r10               0x4c329c8a9d5e7f88

r11               0x297ec2a0266d41ff

r12                     0x3000000008

r13               0xffff800020c77270

r14                            0x100

r15                              0x1

rip               0xffffffff81a668f8    db_enter+0x18

cs                               0x8

rflags                         0x246

rsp               0xffff800020c77250

ss                              0x10

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

ddb{0}>