login: panic: fifo_badop called Stopped at db_enter+0xa: popq %rbp TID PID UID PRFLAGS PFLAGS CPU COMMAND *362907 73202 0 0 0 0 syz-executor9992 db_enter() at db_enter+0xa panic() at panic+0x147 fifo_badop(ffffffff813c6772) at fifo_badop+0x12 VOP_STRATEGY(ffffff006d091600) at VOP_STRATEGY+0x6b bwrite(ffff8000211029c0) at bwrite+0x195 VOP_BWRITE(ffffff0076d5aa28) at VOP_BWRITE+0x47 ufs_mkdir(ffffffff81e0f848) at ufs_mkdir+0x5a9 VOP_MKDIR(ffff8000210c2718,1ed,ffffff9c,ffff800021102978) at VOP_MKDIR+0x65 domkdirat(ffff800021102bb0,ffff8000210c2718,ffff8000210a5cb0,880) at domkdirat+0x10f syscall(0) at syscall+0x3e4 Xsyscall(6,88,9bdb,88,7f7ffffe42f0,7f7ffffe4314) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe4340, count: 4 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> ddb> set $lines = 0 ddb> show panic fifo_badop called ddb> trace db_enter() at db_enter+0xa panic() at panic+0x147 fifo_badop(ffffffff813c6772) at fifo_badop+0x12 VOP_STRATEGY(ffffff006d091600) at VOP_STRATEGY+0x6b bwrite(ffff8000211029c0) at bwrite+0x195 VOP_BWRITE(ffffff0076d5aa28) at VOP_BWRITE+0x47 ufs_mkdir(ffffffff81e0f848) at ufs_mkdir+0x5a9 VOP_MKDIR(ffff8000210c2718,1ed,ffffff9c,ffff800021102978) at VOP_MKDIR+0x65 domkdirat(ffff800021102bb0,ffff8000210c2718,ffff8000210a5cb0,880) at domkdirat+0x10f syscall(0) at syscall+0x3e4 Xsyscall(6,88,9bdb,88,7f7ffffe42f0,7f7ffffe4314) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe4340, count: -11 ddb> show registers rdi 0xffffffff81dfc450 kprintf_mutex rsi 0x5 rbp 0xffff800021102600 rbx 0xffff8000211026a0 rdx 0x3fd rcx 0 rax 0 r8 0xffff8000211025d0 r9 0 r10 0x43338 acpi_pdirpa+0x2f1a0 r11 0xffffffff818f3fa0 x86_bus_space_io_read_1 r12 0x3000000008 r13 0xffff800021102610 r14 0x100 r15 0xffffffff81c29eab apollo_udma66_tim+0x401c rip 0xffffffff8111f55a db_enter+0xa cs 0x8 rflags 0x246 rsp 0xffff800021102600 ss 0x10 db_enter+0xa: popq %rbp ddb> show proc PROC (syz-executor9992) pid=362907 stat=onproc flags process=0 proc=0 pri=17, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000210c2970,0xffff8000210c2278 process=0xffff8000210a5cb0 user=0xffff8000210fd000, vmspace=0xffffff007f12b108 estcpu=36, cpticks=0, pctcpu=0.1 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 69225 69241 28202 0 2 0 syz-executor9992 *73202 362907 28202 0 7 0 syz-executor9992 28202 6745 2615 0 3 0x82 nanosleep syz-executor9992 2615 272803 68111 0 3 0x10008a pause ksh 68111 21306 96065 0 3 0x92 select sshd 31421 15885 1 0 3 0x100083 ttyin getty 96065 65977 1 0 3 0x80 select sshd 90786 57108 20598 73 3 0x100090 kqread syslogd 20598 346773 1 0 3 0x100082 netio syslogd 74436 89412 1 77 3 0x100090 poll dhclient 41809 184409 1 0 3 0x80 poll dhclient 50996 70711 0 0 3 0x14200 pgzero zerothread 99581 371892 0 0 3 0x14200 aiodoned aiodoned 11819 284531 0 0 3 0x14200 syncer update 11928 502700 0 0 3 0x14200 cleaner cleaner 98707 15718 0 0 3 0x14200 reaper reaper 17212 212948 0 0 3 0x14200 pgdaemon pagedaemon 12424 172760 0 0 3 0x14200 bored crynlk 81398 423034 0 0 3 0x14200 bored crypto 67101 432217 0 0 3 0x40014200 acpi0 acpi0 96481 438374 0 0 3 0x14200 bored softnet 72922 179980 0 0 3 0x14200 bored systqmp 12280 258220 0 0 3 0x14200 bored systq 21333 275307 0 0 3 0x40014200 bored softclock 98329 96242 0 0 3 0x40014200 idle0 1 106944 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper