panic: witness_warn Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 4848 5193 0 0 0x4000000 1 syz-executor0 266037 56115 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(bb63f6cb5534989a,0,ffff800020b932d8) at witness_warn+0x6e0 witness_debugger sys/kern/subr_witness.c:2546 [inline] witness_warn(bb63f6cb5534989a,0,ffff800020b932d8) at witness_warn+0x6e0 sys/kern/subr_witness.c:1462 userret(82132f7b00ddf6ad) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(3b0520da977bf51e) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(3b0520da977bf51e) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,5,c,0,3,5cdfc301a0) at Xsyscall+0x128 end of kernel end trace frame: 0x5f11d339a0, 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(bb63f6cb5534989a,0,ffff800020b932d8) at witness_warn+0x6e0 witness_debugger sys/kern/subr_witness.c:2546 [inline] witness_warn(bb63f6cb5534989a,0,ffff800020b932d8) at witness_warn+0x6e0 sys/kern/subr_witness.c:1462 userret(82132f7b00ddf6ad) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(3b0520da977bf51e) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(3b0520da977bf51e) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,5,c,0,3,5cdfc301a0) at Xsyscall+0x128 end of kernel end trace frame: 0x5f11d339a0, count: -6 ddb{1}> show registers rdi 0xffffffff81643507 db_enter+0x17 rsi 0x4276 __ALIGN_SIZE+0x3276 rbp 0xffff800020ca7970 rbx 0xffff800020ca7a10 rdx 0x4277 __ALIGN_SIZE+0x3277 rcx 0xffff800000d46000 rax 0xffff800000d46000 r8 0xffffffff8137ad24 kprintf+0x174 r9 0x1 r10 0xe74d9c6cfb89863 r11 0x506eaef1d8581535 r12 0x3000000008 r13 0xffff800020ca7980 r14 0x100 r15 0x1 rip 0xffffffff81643508 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020ca7960 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor0) pid=4848 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020b92270,0xffffffff822fd3b8 process=0xffff800020b95078 user=0xffff800020ca2000, vmspace=0xfffffd807f00c000 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 5193 340824 4329 0 2 0 syz-executor0 5193 294371 4329 0 3 0x4000080 fsleep syz-executor0 5193 222262 4329 0 2 0x4000000 syz-executor0 * 5193 4848 4329 0 7 0x4000000 syz-executor0 15676 329063 43410 0 2 0x2 syz-executor1 1116 27334 0 0 3 0x14200 bored sosplice 4329 396346 43410 0 3 0x82 nanosleep syz-executor0 43410 32562 16688 0 3 0x82 thrsleep syz-fuzzer 43410 297989 16688 0 3 0x4000082 thrsleep syz-fuzzer 43410 229022 16688 0 3 0x4000082 thrsleep syz-fuzzer 43410 499473 16688 0 3 0x4000082 thrsleep syz-fuzzer 43410 22937 16688 0 3 0x4000082 thrsleep syz-fuzzer 43410 467626 16688 0 3 0x4000082 kqread syz-fuzzer 43410 267811 16688 0 3 0x4000082 thrsleep syz-fuzzer 43410 162958 16688 0 3 0x4000082 thrsleep syz-fuzzer 43410 343379 16688 0 3 0x4000082 thrsleep syz-fuzzer 43410 254158 16688 0 3 0x4000082 thrsleep syz-fuzzer 16688 263880 86699 0 3 0x10008a pause ksh 86699 328136 652 0 3 0x92 select sshd 24127 59716 1 0 3 0x100083 ttyin getty 652 7182 1 0 3 0x80 select sshd 56115 266037 3031 73 7 0x100010 syslogd 3031 442605 1 0 3 0x100082 netio syslogd 89250 258372 1 77 3 0x100090 poll dhclient 82050 476898 1 0 3 0x80 poll dhclient 66201 516700 0 0 3 0x14200 pgzero zerothread 79824 130825 0 0 3 0x14200 aiodoned aiodoned 87259 434687 0 0 3 0x14200 syncer update 96355 207000 0 0 3 0x14200 cleaner cleaner 99894 85712 0 0 3 0x14200 reaper reaper 9813 125834 0 0 3 0x14200 pgdaemon pagedaemon 30237 182930 0 0 3 0x14200 bored crynlk 613 107861 0 0 3 0x14200 bored crypto 43854 277620 0 0 3 0x40014200 acpi0 acpi0 99625 33963 0 0 3 0x40014200 idle1 39475 423231 0 0 3 0x14200 bored softnet 66935 175461 0 0 3 0x14200 bored systqmp 19243 282486 0 0 3 0x14200 bored systq 3067 398143 0 0 3 0x40014200 bored softclock 72557 263291 0 0 3 0x40014200 idle0 1 11724 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper