panic: fifo_badop called Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 93571 79068 32767 0x10 0 0K syz-executor.0 65755 33191 0 0x2 0x4000000 1 syz-fuzzer 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(ffff800024dcd528) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491 VOP_STRATEGY(fffffd8070b59600) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:727 bwrite(fffffd8070b59600) at bwrite+0x1b9 sys/kern/vfs_bio.c:738 VOP_BWRITE(fffffd8070b59600) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:739 ufs_mkdir(ffff800024dcd7b0) at ufs_mkdir+0x6b7 sys/ufs/ufs/ufs_vnops.c:1250 VOP_MKDIR(fffffd8067d68910,ffff800024dcd910,ffff800024dcd960,ffff800024dcd840) at VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 domkdirat(ffff800020a89b40,ffffff9c,7f7fffff2840,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 syscall(ffff800024dcdae0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800024dcdae0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,88,7f7fffff2840,88,0,7f7fffff2864) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff28b0, 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic fifo_badop called ddb{0}> 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(ffff800024dcd528) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491 VOP_STRATEGY(fffffd8070b59600) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:727 bwrite(fffffd8070b59600) at bwrite+0x1b9 sys/kern/vfs_bio.c:738 VOP_BWRITE(fffffd8070b59600) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:739 ufs_mkdir(ffff800024dcd7b0) at ufs_mkdir+0x6b7 sys/ufs/ufs/ufs_vnops.c:1250 VOP_MKDIR(fffffd8067d68910,ffff800024dcd910,ffff800024dcd960,ffff800024dcd840) at VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 domkdirat(ffff800020a89b40,ffffff9c,7f7fffff2840,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 syscall(ffff800024dcdae0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800024dcdae0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,88,7f7fffff2840,88,0,7f7fffff2864) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff28b0, count: -11 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800024dcd450 rbx 0xffff800024dcd500 rdx 0xffff800020a89b40 rcx 0 rax 0 r8 0xffffffff81e7083f kprintf+0x16f r9 0x1 r10 0x25 r11 0x6dbeb9cdbb69ba98 r12 0x3000000008 r13 0xffff800024dcd460 r14 0x100 r15 0x1 rip 0xffffffff81131098 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800024dcd440 ss 0 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=93571 stat=onproc flags process=10 proc=0 pri=17, usrpri=77, nice=20 forw=0xffffffffffffffff, list=0xffff800020a88ee8,0xffffffff82668b20 process=0xffff800020a8ae10 user=0xffff800024dc8000, vmspace=0xfffffd807f00ba10 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND *79068 93571 64631 32767 7 0x10 syz-executor.0 64631 460803 33191 0 3 0x82 wait syz-executor.0 80571 499633 87704 32767 2 0x10 syz-executor.1 87704 254085 33191 0 3 0x82 wait syz-executor.1 97282 468472 0 0 3 0x14200 bored sosplice 33191 156717 29390 0 3 0x82 thrsleep syz-fuzzer 33191 265592 29390 0 3 0x4000082 nanosleep syz-fuzzer 33191 38222 29390 0 3 0x4000082 thrsleep syz-fuzzer 33191 361660 29390 0 2 0x4000002 syz-fuzzer 33191 289678 29390 0 3 0x4000082 thrsleep syz-fuzzer 33191 466065 29390 0 3 0x4000082 thrsleep syz-fuzzer 33191 431094 29390 0 3 0x4000082 thrsleep syz-fuzzer 33191 435395 29390 0 3 0x4000082 thrsleep syz-fuzzer 33191 65755 29390 0 7 0x4000002 syz-fuzzer 33191 452439 29390 0 3 0x4000082 thrsleep syz-fuzzer 29390 340470 93087 0 3 0x10008a pause ksh 93087 62391 44703 0 3 0x92 select sshd 88638 223635 1 0 3 0x100083 ttyin getty 44703 131411 1 0 3 0x80 select sshd 70826 269250 53176 73 3 0x100090 kqread syslogd 53176 192044 1 0 3 0x100082 netio syslogd 43844 89442 1 77 3 0x100090 poll dhclient 66692 117742 1 0 3 0x80 poll dhclient 32921 310278 0 0 2 0x14200 zerothread 72586 274276 0 0 3 0x14200 aiodoned aiodoned 93175 86140 0 0 3 0x14200 syncer update 62602 219361 0 0 3 0x14200 cleaner cleaner 76672 21585 0 0 3 0x14200 reaper reaper 23614 418119 0 0 3 0x14200 pgdaemon pagedaemon 31461 392334 0 0 3 0x14200 bored crynlk 27323 76568 0 0 3 0x14200 bored crypto 50356 57995 0 0 3 0x40014200 acpi0 acpi0 78912 84583 0 0 3 0x40014200 idle1 93332 284474 0 0 3 0x14200 bored softnet 15678 447814 0 0 3 0x14200 bored systqmp 79341 69877 0 0 3 0x14200 bored systq 15616 366841 0 0 3 0x40014200 bored softclock 42420 12244 0 0 3 0x40014200 idle0 22962 166885 0 0 3 0x14200 bored smr 1 184126 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 79068 (syz-executor.0) thread 0xffff800020a89b40 (93571) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82635ac8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 __mp_acquire_count+0x51 sys/kern/kern_lock.c:227 #2 mi_switch+0x392 sys/kern/sched_bsd.c:436 #3 sleep_finish+0x113 sys/kern/kern_synch.c:373 #4 tsleep+0x198 sleep_finish_timeout sys/kern/kern_synch.c:397 [inline] #4 tsleep+0x198 sleep_finish_all sys/kern/kern_synch.c:183 [inline] #4 tsleep+0x198 sys/kern/kern_synch.c:152 #5 biowait+0xa1 sys/kern/vfs_bio.c:1231 #6 bwrite+0x1e4 sys/kern/vfs_bio.c:747 #7 ffs_update+0x2c2 sys/ufs/ffs/ffs_inode.c:113 #8 ufs_mkdir+0x665 sys/ufs/ufs/ufs_vnops.c:1234 #9 VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 #10 domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 #11 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #11 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #12 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806e524098) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 rw_enter+0x447 sys/kern/kern_rwlock.c:306 #2 rrw_enter+0x4f sys/kern/kern_rwlock.c:435 #3 VOP_LOCK+0xf0 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:574 #5 vget+0x1c3 sys/kern/vfs_subr.c:672 #6 ufs_ihashget+0x141 sys/ufs/ufs/ufs_ihash.c:119 #7 ffs_vget+0x74 sys/ufs/ffs/ffs_vfsops.c:1323 #8 ffs_inode_alloc+0x1cf sys/ufs/ffs/ffs_alloc.c:392 #9 ufs_mkdir+0xf4 sys/ufs/ufs/ufs_vnops.c:1164 #10 VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 #11 domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 #12 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #12 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #13 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd80671725e8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 rw_enter+0x447 sys/kern/kern_rwlock.c:306 #2 rrw_enter+0x4f sys/kern/kern_rwlock.c:435 #3 VOP_LOCK+0xf0 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:574 #5 vfs_lookup+0xe6 sys/kern/vfs_lookup.c:419 #6 namei+0x63c sys/kern/vfs_lookup.c:249 #7 domkdirat+0x75 sys/kern/vfs_syscalls.c:2968 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9471 6323K 6323K 78643K 12733 0 0 pcb 13 12K 14K 78643K 17 0 0 rtable 109 3K 3K 78643K 18379 0 0 ifaddr 37 18K 21K 78643K 2729 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 754 0 0 iov 0 0K 44K 78643K 2960 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1215 76K 76K 78643K 10568 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 142 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 9629 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 33K 78643K 17647 0 0 sigio 0 0K 0K 78643K 312 0 0 proc 48 50K 90K 78643K 20710 0 0 subproc 34 2K 2K 78643K 7429 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 2K 78643K 6838 0 0 in_multi 33 2K 2K 78643K 5302 0 0 ether_multi 1 0K 0K 78643K 54 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 114 503K 503K 78643K 114 0 0 exec 0 0K 1K 78643K 7709 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 167 25K 37K 78643K 66363 0 0 UVM aobj 130 5K 5K 78643K 141 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 0K 78643K 1259 0 0 NDP 5 0K 0K 78643K 1314 0 0 temp 121 3558K 3654K 78643K 91833 0 0 kqueue 0 0K 0K 78643K 222 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 920 0 914 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 11525 0 11523 1 0 1 1 0 8 0 rtentry 112 4443 0 4397 2 0 2 2 0 8 0 unpcb 120 16084 0 16053 45 43 2 2 0 8 0 syncache 264 111 0 111 54 53 1 1 0 8 1 sackhl 24 3 0 3 3 3 0 1 0 8 0 tcpqe 32 39 0 39 26 26 0 1 0 8 0 tcpcb 544 8964 0 8960 173 171 2 14 0 8 1 ipq 40 162 0 162 61 60 1 1 0 8 1 ipqe 40 5017 0 5017 61 60 1 1 0 8 1 inpcb 280 26151 0 26140 187 185 2 13 0 8 1 ip6q 72 8 0 8 5 5 0 1 0 8 0 ip6af 40 241 0 241 5 5 0 1 0 8 0 nd6 48 876 0 872 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 19714 0 19469 16 0 16 16 0 8 0 art_table 32 19715 0 19469 10 8 2 3 0 8 0 art_node 16 4442 0 4400 1 0 1 1 0 8 0 sysvmsgpl 40 29 0 12 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 9623 0 9613 1 0 1 1 0 8 0 shmpl 112 139 0 11 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 18397 0 16959 48 1 47 47 0 8 0 ffsino 272 18397 0 16959 105 9 96 96 0 8 0 nchpl 144 39755 0 38111 66 4 62 62 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 208 5926 0 0 312 0 312 312 0 8 0 namei 1024 188954 0 188953 3 2 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 129788 0 129788 154 152 2 7 0 8 2 plimitpl 152 2923 0 2914 1 0 1 1 0 8 0 sigapl 432 16513 0 16499 27 25 2 3 0 8 0 futexpl 56 349296 0 349296 4 3 1 1 0 8 1 knotepl 112 14614 0 14595 17 16 1 3 0 8 0 kqueuepl 104 13366 0 13364 44 43 1 4 0 8 0 pipepl 112 20648 0 20629 47 45 2 2 0 8 1 fdescpl 488 16514 0 16499 3 0 3 3 0 8 1 filepl 152 163480 0 163382 238 233 5 14 0 8 1 lockfpl 104 4232 0 4231 1 0 1 1 0 8 0 lockfspl 48 1451 0 1450 1 0 1 1 0 8 0 sessionpl 112 452 0 442 1 0 1 1 0 8 0 pgrppl 48 526 0 516 1 0 1 1 0 8 0 ucredpl 96 25741 0 25732 1 0 1 1 0 8 0 zombiepl 144 16499 0 16499 3 2 1 1 0 8 1 processpl 896 16530 0 16499 4 0 4 4 0 8 0 procpl 632 46482 0 46442 13 8 5 5 0 8 1 srpgc 64 870 0 870 68 67 1 1 0 8 1 sosppl 128 435 0 435 88 87 1 1 0 8 1 sockpl 384 54110 0 54068 358 351 7 24 0 8 1 mcl64k 65536 103 0 0 6 3 3 3 0 8 0 mcl16k 16384 55 0 0 5 2 3 3 0 8 0 mcl12k 12288 65 0 0 2 0 2 2 0 8 0 mcl9k 9216 65 0 0 3 1 2 2 0 8 0 mcl8k 8192 33 0 0 3 0 3 3 0 8 0 mcl4k 4096 25 0 0 3 0 3 3 0 8 0 mcl2k2 2112 18 0 0 2 0 2 2 0 8 0 mcl2k 2048 185 0 0 18 6 12 18 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 2063 0 0 28 0 28 28 0 8 0 bufpl 256 60660 0 53616 441 0 441 441 0 8 0 anonpl 16 2439807 0 2428015 332 270 62 82 0 124 0 amapchunkpl 152 172346 0 172243 336 324 12 19 0 158 5 amappl16 192 81615 0 80921 535 493 42 58 0 8 0 amappl15 184 2116 0 2113 47 46 1 1 0 8 0 amappl14 176 5264 0 5253 1 0 1 1 0 8 0 amappl13 168 1398 0 1398 39 39 0 1 0 8 0 amappl12 160 1993 0 1979 2 1 1 1 0 8 0 amappl11 152 2807 0 2796 1 0 1 1 0 8 0 amappl10 144 1437 0 1428 1 0 1 1 0 8 0 amappl9 136 7634 0 7628 1 0 1 1 0 8 0 amappl8 128 6283 0 6150 6 1 5 5 0 8 0 amappl7 120 3008 0 2998 1 0 1 1 0 8 0 amappl6 112 2075 0 2050 1 0 1 1 0 8 0 amappl5 104 5276 0 5266 1 0 1 1 0 8 0 amappl4 96 16153 0 16111 11 9 2 2 0 8 0 amappl3 88 3491 0 3486 1 0 1 1 0 8 0 amappl2 80 99110 0 99033 3 1 2 3 0 8 0 amappl1 72 477784 0 477376 48 39 9 20 0 8 0 amappl 80 54107 0 54072 3 1 2 2 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 64 140 0 11 3 0 3 3 0 8 0 uaddrrnd 24 16514 0 16499 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 16514 0 16499 1 0 1 1 0 8 0 vmmpekpl 168 170485 0 170456 2 0 2 2 0 8 0 vmmpepl 168 2345532 0 2343603 726 602 124 135 0 357 16 vmsppl 368 16513 0 16499 2 0 2 2 0 8 0 pdppl 4096 33035 0 32998 8 2 6 6 0 8 1 pvpl 32 6291372 0 6276374 972 828 144 193 0 265 0 pmappl 232 16513 0 16499 78 76 2 2 0 8 1 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 817 0 197 28 10 18 19 0 8 0