panic: fifo_badop called Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *395741 73913 0 0x2 0 0 syz-executor.0 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 fifo_badop(ffff8000159faa18) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491 VOP_STRATEGY(fffffd8024bc0c00) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:727 bwrite(fffffd8024bc0c00) at bwrite+0x206 sys/kern/vfs_bio.c:738 VOP_BWRITE(fffffd8024bc0c00) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:739 ufs_mkdir(ffff8000159faca0) at ufs_mkdir+0x6b7 sys/ufs/ufs/ufs_vnops.c:1250 VOP_MKDIR(fffffd802b8095b8,ffff8000159fae00,ffff8000159fae50,ffff8000159fad30) at VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 domkdirat(ffff800014916ee8,ffffff9c,7f7ffffe8b10,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 syscall(ffff8000159fafd0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,88,7f7ffffe8b10,88,0,7f7ffffe8b34) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe8b80, 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> set $maxwidth = 0 ddb> show panic fifo_badop called ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 fifo_badop(ffff8000159faa18) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491 VOP_STRATEGY(fffffd8024bc0c00) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:727 bwrite(fffffd8024bc0c00) at bwrite+0x206 sys/kern/vfs_bio.c:738 VOP_BWRITE(fffffd8024bc0c00) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:739 ufs_mkdir(ffff8000159faca0) at ufs_mkdir+0x6b7 sys/ufs/ufs/ufs_vnops.c:1250 VOP_MKDIR(fffffd802b8095b8,ffff8000159fae00,ffff8000159fae50,ffff8000159fad30) at VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 domkdirat(ffff800014916ee8,ffffff9c,7f7ffffe8b10,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 syscall(ffff8000159fafd0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,88,7f7ffffe8b10,88,0,7f7ffffe8b34) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe8b80, count: -11 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff8000159fa940 rbx 0xffff8000159fa9f0 rdx 0x2 rcx 0 rax 0 r8 0xffff8000159fa900 r9 0x1 r10 0 r11 0x35dc2c3aa7e6dcb5 r12 0x3000000008 r13 0xffff8000159fa950 r14 0x100 r15 0x1 rip 0xffffffff8208d768 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000159fa930 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (syz-executor.0) pid=395741 stat=onproc flags process=2 proc=0 pri=17, usrpri=79, nice=20 forw=0xffffffffffffffff, list=0xffff8000149169f8,0xffff8000149178d8 process=0xffff8000ffff6d90 user=0xffff8000159f6000, vmspace=0xfffffd803f013000 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 24119 139114 84867 0 2 0 syz-executor.1 24119 263344 84867 0 2 0x4000000 syz-executor.1 *73913 395741 3952 0 7 0x2 syz-executor.0 64797 478799 0 0 3 0x14200 acct acct 84867 429544 3952 0 3 0x82 nanosleep syz-executor.1 74079 241335 1 0 3 0x100083 ttyin getty 64820 482104 0 0 3 0x14200 bored sosplice 3952 409848 7451 0 3 0x82 thrsleep syz-fuzzer 3952 376276 7451 0 3 0x4000082 nanosleep syz-fuzzer 3952 422247 7451 0 3 0x4000082 thrsleep syz-fuzzer 3952 105124 7451 0 3 0x4000082 thrsleep syz-fuzzer 3952 420044 7451 0 3 0x4000082 thrsleep syz-fuzzer 3952 410364 7451 0 3 0x4000082 thrsleep syz-fuzzer 3952 473327 7451 0 3 0x4000082 thrsleep syz-fuzzer 3952 94820 7451 0 3 0x4000082 kqread syz-fuzzer 7451 221232 13599 0 3 0x10008a pause ksh 13599 171905 25751 0 3 0x92 select sshd 25751 313315 1 0 3 0x80 select sshd 76353 182330 68342 73 3 0x100090 kqread syslogd 68342 517246 1 0 3 0x100082 netio syslogd 55347 52094 0 0 2 0x14200 zerothread 82008 426643 0 0 3 0x14200 aiodoned aiodoned 72819 2537 0 0 3 0x14200 syncer update 53192 460033 0 0 3 0x14200 cleaner cleaner 55858 471876 0 0 3 0x14200 reaper reaper 94613 364325 0 0 3 0x14200 pgdaemon pagedaemon 79703 339804 0 0 3 0x14200 bored crynlk 17326 407822 0 0 3 0x14200 bored crypto 96547 32649 0 0 3 0x40014200 acpi0 acpi0 83996 423526 0 0 3 0x14200 bored softnet 42893 220345 0 0 3 0x14200 bored systqmp 75423 400081 0 0 3 0x14200 bored systq 61521 148167 0 0 3 0x40014200 bored softclock 69117 64079 0 0 3 0x40014200 idle0 42951 169374 0 0 3 0x14200 bored smr 1 163175 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9608 6965K 15473K 78643K 82576 0 0 pcb 13 11K 12K 78643K 3469 0 0 rtable 111 12K 13K 78643K 9186 0 0 ifaddr 101 26K 28K 78643K 1833 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 7180 0 0 iov 0 0K 32K 78643K 5246 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1234 77K 79K 78643K 22317 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 143 0 0 VM map 120 30K 30K 78643K 179 0 0 sem 12 0K 1K 78643K 5415 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 5 13K 25K 78643K 16296 0 0 sigio 0 0K 0K 78643K 668 0 0 proc 45 30K 62K 78643K 4055 0 0 subproc 32 2K 2K 78643K 1158 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 3834 0 0 in_multi 27 1K 2K 78643K 2376 0 0 ether_multi 1 0K 0K 78643K 108 0 0 mrt 1 0K 0K 78643K 56 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 96 424K 424K 78643K 96 0 0 exec 0 0K 1K 78643K 2169 0 0 pfkey data 0 0K 4K 78643K 4 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 286 984K 985K 78643K 40100 0 0 UVM aobj 130 4K 4K 78643K 130 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 1K 78643K 2927 0 0 NDP 24 0K 1K 78643K 734 0 0 temp 254 3545K 4185K 78643K 754227 0 0 kqueue 0 0K 0K 78643K 99 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 456 0 451 1 0 1 1 0 8 0 rtpcb 80 3570 0 3570 4 3 1 1 0 8 1 rtentry 112 2571 0 2533 2 0 2 2 0 8 0 unpcb 120 5231 0 5216 3 2 1 2 0 8 0 syncache 264 50 0 50 27 27 0 1 0 8 0 sackhl 24 4 0 4 4 4 0 1 0 8 0 tcpqe 32 26 0 26 15 15 0 1 0 8 0 tcpcb 544 21670 0 21665 70 68 2 15 0 8 1 ipq 40 91 0 91 36 35 1 1 0 8 1 ipqe 40 2441 0 2441 36 35 1 1 0 8 1 inpcb 280 35312 0 35307 64 62 2 9 0 8 1 rttmr 72 21 0 20 10 9 1 1 0 8 0 ip6q 72 2 0 2 2 2 0 1 0 8 0 ip6af 40 6 0 6 2 2 0 1 0 8 0 nd6 48 338 0 336 8 7 1 1 0 8 0 pkpcb 40 19 0 19 10 10 0 1 0 8 0 swfcl 56 5 0 0 1 0 1 1 0 8 0 ppxss 1128 188 0 188 55 55 0 1 0 8 0 art_heap8 4096 59 0 58 31 30 1 3 0 8 0 art_heap4 256 13772 0 13543 62 44 18 21 0 8 0 art_table 32 13831 0 13601 4 1 3 3 0 8 0 art_node 16 2570 0 2535 1 0 1 1 0 8 0 sysvmsgpl 40 84 0 84 1 1 0 1 0 8 0 semapl 112 5413 0 5403 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 25483 0 24024 48 0 48 48 0 8 0 ffsino 240 25483 0 24024 87 0 87 87 0 8 0 nchpl 144 47125 0 46649 60 40 20 60 0 8 0 uvmvnodes 72 7891 0 0 144 0 144 144 0 8 0 vnodes 208 7891 0 0 416 0 416 416 0 8 0 namei 1024 172607 0 172604 2 1 1 1 0 8 0 vcpupl 1984 119 0 1 15 0 15 15 0 8 0 vmpool 520 177 0 59 10 2 8 8 0 8 0 scsiplug 64 12 0 12 10 10 0 1 0 8 0 scxspl 192 159295 0 159295 65 63 2 7 0 8 2 plimitpl 152 1261 0 1255 1 0 1 1 0 8 0 sigapl 432 16274 0 16263 2 0 2 2 0 8 0 futexpl 56 483085 0 483085 3 2 1 1 0 8 1 knotepl 112 2633 0 2614 3 2 1 2 0 8 0 kqueuepl 104 4628 0 4626 10 9 1 4 0 8 0 pipepl 112 8018 0 7999 28 27 1 2 0 8 0 fdescpl 424 16275 0 16263 2 0 2 2 0 8 0 filepl 120 142060 0 141974 66 62 4 11 0 8 1 lockfpl 104 4949 0 4949 1 0 1 1 0 8 1 lockfspl 48 1740 0 1740 1 0 1 1 0 8 1 sessionpl 112 88 0 80 1 0 1 1 0 8 0 pgrppl 48 210 0 202 1 0 1 1 0 8 0 ucredpl 96 19952 0 19945 1 0 1 1 0 8 0 zombiepl 144 16270 0 16270 1 0 1 1 0 8 1 processpl 864 16298 0 16270 4 0 4 4 0 8 0 procpl 632 35603 0 35567 6 2 4 5 0 8 0 sosppl 128 213 0 213 46 46 0 1 0 8 0 sockpl 384 44307 0 44287 109 104 5 14 0 8 1 mcl64k 65536 3840 0 3583 260 227 33 64 0 8 0 mcl16k 16384 118 0 118 49 48 1 1 0 8 1 mcl12k 12288 310 0 310 45 44 1 1 0 8 1 mcl9k 9216 335 0 335 53 52 1 1 0 8 1 mcl8k 8192 580 0 580 25 24 1 1 0 8 1 mcl4k 4096 2891 0 2891 6 5 1 1 0 8 1 mcl2k2 2112 106 0 106 57 56 1 1 0 8 1 mcl2k 2048 93460 0 93421 29 23 6 11 0 8 0 mtagpl 80 597 0 597 17 15 2 2 0 8 2 mbufpl 256 291485 0 291157 415 377 38 63 0 8 8 bufpl 256 55947 0 48041 497 2 495 495 0 8 0 anonpl 16 1778301 0 1757279 422 321 101 112 0 62 14 amapchunkpl 152 74336 0 74205 166 160 6 19 0 158 0 amappl16 192 95123 0 93865 482 411 71 81 0 8 7 amappl15 184 1696 0 1695 1 0 1 1 0 8 0 amappl14 176 2529 0 2525 1 0 1 1 0 8 0 amappl13 168 1174 0 1174 10 10 0 1 0 8 0 amappl12 160 4501 0 4498 1 0 1 1 0 8 0 amappl11 152 1757 0 1753 1 0 1 1 0 8 0 amappl10 144 902 0 899 1 0 1 1 0 8 0 amappl9 136 4131 0 4125 1 0 1 1 0 8 0 amappl8 128 3586 0 3532 3 1 2 2 0 8 0 amappl7 120 1163 0 1155 1 0 1 1 0 8 0 amappl6 112 1658 0 1647 1 0 1 1 0 8 0 amappl5 104 5223 0 5214 1 0 1 1 0 8 0 amappl4 96 14987 0 14961 1 0 1 1 0 8 0 amappl3 88 4511 0 4497 1 0 1 1 0 8 0 amappl2 80 126403 0 126329 3 1 2 3 0 8 0 amappl1 72 302822 0 302445 26 17 9 20 0 8 0 amappl 80 37039 0 36939 4 1 3 3 0 84 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 17 0 17 1 1 0 1 0 8 0 aobjpl 64 129 0 0 3 0 3 3 0 8 0 uaddrrnd 24 16452 0 16263 2 0 2 2 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 16452 0 16263 2 0 2 2 0 8 0 vmmpekpl 168 94764 0 94715 3 0 3 3 0 8 0 vmmpepl 168 1941018 0 1938394 869 711 158 162 0 357 30 vmsppl 272 16274 0 16263 13 12 1 2 0 8 0 pdppl 4096 32910 0 32762 25 6 19 19 0 8 0 pvpl 32 4648894 0 4627135 875 660 215 271 0 265 32 pmappl 200 16451 0 16322 7 0 7 7 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 1576 0 869 21 0 21 21 0 8 0