panic: witness_warn Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 62017 78835 32767 0x10 0x4000000 1 syz-executor0 376419 44597 73 0x100010 0 0 syslogd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 witness_warn(f151132906c47939,0,ffff800020c442f8) at witness_warn+0x6e0 witness_debugger sys/kern/subr_witness.c:2546 [inline] witness_warn(f151132906c47939,0,ffff800020c442f8) at witness_warn+0x6e0 sys/kern/subr_witness.c:1462 userret(abb3e9b46ab271e6) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(a2a79937087e0f38) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(a2a79937087e0f38) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,9,ffffffffffffff47,0,3,e51db0684c0) at Xsyscall+0x128 end of kernel end trace frame: 0xe54a62f99a0, 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{1}> ddb{1}> set $lines = 0 ddb{1}> show panic witness_warn ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 witness_warn(f151132906c47939,0,ffff800020c442f8) at witness_warn+0x6e0 witness_debugger sys/kern/subr_witness.c:2546 [inline] witness_warn(f151132906c47939,0,ffff800020c442f8) at witness_warn+0x6e0 sys/kern/subr_witness.c:1462 userret(abb3e9b46ab271e6) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(a2a79937087e0f38) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(a2a79937087e0f38) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,9,ffffffffffffff47,0,3,e51db0684c0) at Xsyscall+0x128 end of kernel end trace frame: 0xe54a62f99a0, count: -6 ddb{1}> show registers rdi 0xffffffff81885667 db_enter+0x17 rsi 0x625e __ALIGN_SIZE+0x525e rbp 0xffff800020cf37a0 rbx 0xffff800020cf3840 rdx 0x625f __ALIGN_SIZE+0x525f rcx 0xffff800002f4b000 rax 0xffff800002f4b000 r8 0xffffffff81c79d54 kprintf+0x174 r9 0x1 r10 0xd7d34d39b5775a01 r11 0x282cb2c634b09bb5 r12 0x3000000008 r13 0xffff800020cf37b0 r14 0x100 r15 0x1 rip 0xffffffff81885668 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020cf3790 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor0) pid=62017 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffff800020b74008,0xffffffff822f29c0 process=0xffff800020b95708 user=0xffff800020cee000, vmspace=0xfffffd807f00c870 estcpu=31, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 69073 319817 63086 32767 3 0x90 nanosleep syz-executor1 69073 234431 63086 32767 3 0x4000090 netio syz-executor1 69073 283907 63086 32767 3 0x4000090 netlck syz-executor1 69073 89736 63086 32767 3 0x4000090 fsleep syz-executor1 78835 55781 77633 32767 2 0x10 syz-executor0 78835 494646 77633 32767 3 0x4000090 ttyout syz-executor0 78835 404566 77633 32767 3 0x4000090 ttyout syz-executor0 78835 158302 77633 32767 3 0x4000090 ttyout syz-executor0 78835 184360 77633 32767 2 0x4000010 syz-executor0 78835 297753 77633 32767 3 0x4000090 fsleep syz-executor0 78835 173735 77633 32767 3 0x4000090 fsleep syz-executor0 *78835 62017 77633 32767 7 0x4000010 syz-executor0 77633 35972 16495 32767 2 0x490 syz-executor0 16495 44357 13041 0 3 0x82 wait syz-executor0 63086 241446 54564 32767 3 0x90 nanosleep syz-executor1 54564 164734 13041 0 3 0x82 wait syz-executor1 7668 307438 0 0 3 0x14200 bored sosplice 13041 308578 40592 0 3 0x82 thrsleep syz-fuzzer 13041 373473 40592 0 3 0x4000082 thrsleep syz-fuzzer 13041 516123 40592 0 3 0x4000082 thrsleep syz-fuzzer 13041 111578 40592 0 3 0x4000082 thrsleep syz-fuzzer 13041 377256 40592 0 3 0x4000082 thrsleep syz-fuzzer 13041 217792 40592 0 3 0x4000082 thrsleep syz-fuzzer 13041 497811 40592 0 3 0x4000082 thrsleep syz-fuzzer 13041 217772 40592 0 3 0x4000082 kqread syz-fuzzer 13041 205557 40592 0 3 0x4000082 thrsleep syz-fuzzer 13041 26965 40592 0 3 0x4000082 thrsleep syz-fuzzer 13041 455178 40592 0 3 0x4000082 thrsleep syz-fuzzer 13041 191410 40592 0 3 0x4000082 thrsleep syz-fuzzer 40592 78426 64887 0 3 0x10008a pause ksh 64887 419858 38392 0 3 0x92 select sshd 10997 79249 1 0 3 0x100083 ttyin getty 38392 3901 1 0 3 0x80 select sshd 44597 376419 72835 73 7 0x100010 syslogd 72835 107316 1 0 3 0x100082 netio syslogd 62048 393097 1 77 3 0x100090 poll dhclient 63983 426722 1 0 3 0x80 poll dhclient 73205 331032 0 0 3 0x14200 pgzero zerothread 16455 69552 0 0 3 0x14200 aiodoned aiodoned 37373 109542 0 0 3 0x14200 syncer update 36235 114607 0 0 3 0x14200 cleaner cleaner 63896 517521 0 0 3 0x14200 reaper reaper 50309 261320 0 0 3 0x14200 pgdaemon pagedaemon 29782 260280 0 0 3 0x14200 bored crynlk 187 25387 0 0 3 0x14200 bored crypto 7017 341497 0 0 3 0x40014200 acpi0 acpi0 95760 206409 0 0 3 0x40014200 idle1 16737 20168 0 0 3 0x14200 bored softnet 35448 92361 0 0 3 0x14200 bored systqmp 87727 115834 0 0 3 0x14200 bored systq 47447 288043 0 0 3 0x40014200 bored softclock 46115 78376 0 0 3 0x40014200 idle0 1 204124 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper