panic: witness_warn Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *226373 45454 32767 0x10 0x4000000 0 syz-executor1 19121 51051 32767 0x10 0 1 syz-executor0 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(f99af8fba33e9cd9,0,ffff800020b92978) at witness_warn+0x6e0 witness_debugger sys/kern/subr_witness.c:2546 [inline] witness_warn(f99af8fba33e9cd9,0,ffff800020b92978) at witness_warn+0x6e0 sys/kern/subr_witness.c:1462 userret(3232b2b6bfbd612) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(58d1ac6ad5643fe5) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(58d1ac6ad5643fe5) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,5,d,0,3,1df9f0f11a0) at Xsyscall+0x128 end of kernel end trace frame: 0x1e19f4ce970, 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 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 witness_warn(f99af8fba33e9cd9,0,ffff800020b92978) at witness_warn+0x6e0 witness_debugger sys/kern/subr_witness.c:2546 [inline] witness_warn(f99af8fba33e9cd9,0,ffff800020b92978) at witness_warn+0x6e0 sys/kern/subr_witness.c:1462 userret(3232b2b6bfbd612) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(58d1ac6ad5643fe5) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(58d1ac6ad5643fe5) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,5,d,0,3,1df9f0f11a0) at Xsyscall+0x128 end of kernel end trace frame: 0x1e19f4ce970, count: -6 ddb{0}> show registers rdi 0xffffffff81391847 db_enter+0x17 rsi 0x3ff3 __ALIGN_SIZE+0x2ff3 rbp 0xffff800020cc3380 rbx 0xffff800020cc3420 rdx 0x3ff4 __ALIGN_SIZE+0x2ff4 rcx 0xffff800000b46000 rax 0xffff800000b46000 r8 0xffffffff815d9fe4 kprintf+0x174 r9 0x1 r10 0x191c99344159b2e2 r11 0x7601d4ef868d2c61 r12 0x3000000008 r13 0xffff800020cc3390 r14 0x100 r15 0x1 rip 0xffffffff81391848 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020cc3370 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor1) pid=226373 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020b92018,0xffffffff82319e38 process=0xffff800020b94358 user=0xffff800020cbe000, vmspace=0xfffffd806e9305a8 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 45454 444526 25590 32767 2 0x10 syz-executor1 45454 38623 25590 32767 3 0x4000090 fsleep syz-executor1 45454 382005 25590 32767 2 0x4000010 syz-executor1 *45454 226373 25590 32767 7 0x4000010 syz-executor1 97392 356257 51051 32767 3 0x90 nanosleep syz-executor0 97392 302206 51051 32767 3 0x4000090 kqread syz-executor0 51051 19121 21800 32767 7 0x10 syz-executor0 21800 388309 85032 0 3 0x82 wait syz-executor0 25590 513687 19818 32767 2 0x490 syz-executor1 19818 72747 85032 0 3 0x82 wait syz-executor1 93910 81751 0 0 3 0x14200 bored sosplice 85032 58437 93348 0 3 0x82 thrsleep syz-fuzzer 85032 50082 93348 0 3 0x4000082 thrsleep syz-fuzzer 85032 116651 93348 0 3 0x4000082 thrsleep syz-fuzzer 85032 47086 93348 0 3 0x4000082 thrsleep syz-fuzzer 85032 400390 93348 0 3 0x4000082 thrsleep syz-fuzzer 85032 170827 93348 0 3 0x4000082 kqread syz-fuzzer 85032 12640 93348 0 3 0x4000082 thrsleep syz-fuzzer 85032 179005 93348 0 3 0x4000082 thrsleep syz-fuzzer 85032 345724 93348 0 3 0x4000082 thrsleep syz-fuzzer 85032 116394 93348 0 3 0x4000082 thrsleep syz-fuzzer 93348 481026 41573 0 3 0x10008a pause ksh 41573 335931 2259 0 3 0x92 select sshd 68602 226103 1 0 3 0x100083 ttyin getty 2259 151963 1 0 3 0x80 select sshd 84456 78777 94792 73 2 0x100090 syslogd 94792 118328 1 0 3 0x100082 netio syslogd 44836 255654 1 77 3 0x100090 poll dhclient 69172 400903 1 0 3 0x80 poll dhclient 91789 381848 0 0 3 0x14200 pgzero zerothread 14636 292248 0 0 3 0x14200 aiodoned aiodoned 57041 50222 0 0 3 0x14200 syncer update 51551 47323 0 0 3 0x14200 cleaner cleaner 79769 236857 0 0 3 0x14200 reaper reaper 20210 30429 0 0 3 0x14200 pgdaemon pagedaemon 8988 455807 0 0 3 0x14200 bored crynlk 48100 129951 0 0 3 0x14200 bored crypto 49883 509368 0 0 3 0x40014200 acpi0 acpi0 79534 331383 0 0 3 0x40014200 idle1 280 185124 0 0 3 0x14200 bored softnet 20031 162778 0 0 3 0x14200 bored systqmp 48562 416351 0 0 3 0x14200 bored systq 56311 279219 0 0 3 0x40014200 bored softclock 60876 279319 0 0 3 0x40014200 idle0 1 97033 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper