panic: fifo_badop called Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *460919 83739 32767 0x10 0 0K syz-executor.1 160082 18567 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(ffff80002135f6a8) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491 VOP_STRATEGY(fffffd80673fe300) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:727 bwrite(fffffd80673fe300) at bwrite+0x1b9 sys/kern/vfs_bio.c:738 VOP_BWRITE(fffffd80673fe300) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:739 ufs_mkdir(ffff80002135f930) at ufs_mkdir+0x6b7 sys/ufs/ufs/ufs_vnops.c:1250 VOP_MKDIR(fffffd806658c5b8,ffff80002135fa90,ffff80002135fae0,ffff80002135f9c0) at VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 domkdirat(ffff800020ab18c8,ffffff9c,7f7ffffef1a0,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 syscall(ffff80002135fc60) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff80002135fc60) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,88,7f7ffffef1a0,88,0,7f7ffffef1c4) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffef210, 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(ffff80002135f6a8) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491 VOP_STRATEGY(fffffd80673fe300) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:727 bwrite(fffffd80673fe300) at bwrite+0x1b9 sys/kern/vfs_bio.c:738 VOP_BWRITE(fffffd80673fe300) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:739 ufs_mkdir(ffff80002135f930) at ufs_mkdir+0x6b7 sys/ufs/ufs/ufs_vnops.c:1250 VOP_MKDIR(fffffd806658c5b8,ffff80002135fa90,ffff80002135fae0,ffff80002135f9c0) at VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 domkdirat(ffff800020ab18c8,ffffff9c,7f7ffffef1a0,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 syscall(ffff80002135fc60) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff80002135fc60) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,88,7f7ffffef1a0,88,0,7f7ffffef1c4) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffef210, count: -11 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff80002135f5d0 rbx 0xffff80002135f680 rdx 0xffff800020ab18c8 rcx 0 rax 0 r8 0xffffffff817abe2f kprintf+0x16f r9 0x1 r10 0x25 r11 0xfe1b136c9b50db69 r12 0x3000000008 r13 0xffff80002135f5e0 r14 0x100 r15 0x1 rip 0xffffffff815f6b58 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002135f5c0 ss 0 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=460919 stat=onproc flags process=10 proc=0 pri=17, usrpri=53, nice=20 forw=0xffffffffffffffff, list=0xffff800020ab0508,0xffffffff826417a8 process=0xffff800020a8aa90 user=0xffff80002135a000, vmspace=0xfffffd807f00b2e0 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND *83739 460919 62566 32767 7 0x10 syz-executor.1 62566 208040 18567 0 3 0x82 wait syz-executor.1 63020 431768 25182 32767 2 0x10 syz-executor.0 25182 225320 18567 0 3 0x82 wait syz-executor.0 88925 328118 0 0 3 0x14200 bored sosplice 18567 56250 95408 0 3 0x82 thrsleep syz-fuzzer 18567 522331 95408 0 3 0x4000082 nanosleep syz-fuzzer 18567 63258 95408 0 3 0x4000082 thrsleep syz-fuzzer 18567 467064 95408 0 3 0x4000082 thrsleep syz-fuzzer 18567 360378 95408 0 3 0x4000082 thrsleep syz-fuzzer 18567 34926 95408 0 2 0x4000002 syz-fuzzer 18567 276892 95408 0 3 0x4000082 thrsleep syz-fuzzer 18567 114891 95408 0 3 0x4000082 thrsleep syz-fuzzer 18567 323435 95408 0 3 0x4000082 thrsleep syz-fuzzer 18567 160082 95408 0 7 0x4000002 syz-fuzzer 95408 330205 88365 0 3 0x10008a pause ksh 88365 429274 54720 0 3 0x92 select sshd 54497 429851 1 0 3 0x100083 ttyin getty 54720 497230 1 0 3 0x80 select sshd 9524 165109 59338 73 3 0x100090 kqread syslogd 59338 446616 1 0 3 0x100082 netio syslogd 17090 196690 1 77 3 0x100090 poll dhclient 216 360544 1 0 3 0x80 poll dhclient 12664 492317 0 0 2 0x14200 zerothread 21923 23653 0 0 3 0x14200 aiodoned aiodoned 54073 349091 0 0 3 0x14200 syncer update 88563 200995 0 0 3 0x14200 cleaner cleaner 92199 508065 0 0 3 0x14200 reaper reaper 97762 493882 0 0 3 0x14200 pgdaemon pagedaemon 68915 213407 0 0 3 0x14200 bored crynlk 60034 491488 0 0 3 0x14200 bored crypto 50206 1268 0 0 3 0x40014200 acpi0 acpi0 65994 276235 0 0 3 0x40014200 idle1 771 319052 0 0 3 0x14200 bored softnet 22574 205791 0 0 3 0x14200 bored systqmp 57772 109566 0 0 3 0x14200 bored systq 58455 295570 0 0 3 0x40014200 bored softclock 81312 210527 0 0 3 0x40014200 idle0 76605 203029 0 0 3 0x14200 bored smr 1 248527 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 83739 (syz-executor.1) thread 0xffff800020ab18c8 (460919) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82662ed0) #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 (0xfffffd806794c5f8) #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 (0xfffffd806794ce78) #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 11278 0 0 pcb 13 12K 14K 78643K 17 0 0 rtable 105 3K 3K 78643K 6276 0 0 ifaddr 37 14K 15K 78643K 925 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 310 0 0 iov 0 0K 32K 78643K 1148 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1216 76K 76K 78643K 4496 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 5K 78643K 74 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 132 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 33K 78643K 6052 0 0 sigio 0 0K 0K 78643K 103 0 0 proc 48 50K 83K 78643K 7058 0 0 subproc 34 2K 2K 78643K 2482 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 1K 78643K 1162 0 0 in_multi 33 2K 2K 78643K 1734 0 0 ether_multi 1 0K 0K 78643K 26 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 2660 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 139 24K 33K 78643K 23020 0 0 UVM aobj 130 5K 5K 78643K 137 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 1189 0 0 NDP 9 0K 0K 78643K 441 0 0 temp 121 3558K 3639K 78643K 33976 0 0 kqueue 0 0K 0K 78643K 204 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 64 313 0 307 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 2162 0 2160 1 0 1 1 0 8 0 rtentry 112 1504 0 1460 2 0 2 2 0 8 0 unpcb 120 5195 0 5177 11 9 2 2 0 8 1 syncache 264 51 0 51 12 12 0 1 0 8 0 tcpqe 32 8 0 8 6 6 0 1 0 8 0 tcpcb 544 2320 0 2316 22 21 1 12 0 8 0 ipq 40 74 0 74 23 23 0 1 0 8 0 ipqe 40 1753 0 1753 23 23 0 1 0 8 0 inpcb 280 8951 0 8941 49 46 3 13 0 8 2 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 48 292 0 288 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 6606 0 6390 14 0 14 14 0 8 0 art_table 32 6607 0 6390 2 0 2 2 0 8 0 art_node 16 1503 0 1463 1 0 1 1 0 8 0 sysvmsgpl 40 34 0 22 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 126 0 116 1 0 1 1 0 8 0 shmpl 112 135 0 7 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 7903 0 6480 47 1 46 47 0 8 0 ffsino 272 7903 0 6480 99 3 96 96 0 8 0 nchpl 144 15875 0 14261 60 0 60 60 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 73278 0 73277 3 2 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 49927 0 49927 59 57 2 7 0 8 2 plimitpl 152 1039 0 1030 1 0 1 1 0 8 0 sigapl 432 5791 0 5777 11 8 3 3 0 8 1 futexpl 56 131787 0 131787 3 2 1 1 0 8 1 knotepl 112 7489 0 7470 9 8 1 2 0 8 0 kqueuepl 104 7787 0 7785 15 14 1 4 0 8 0 pipepl 112 5956 0 5937 15 14 1 2 0 8 0 fdescpl 488 5792 0 5777 4 1 3 3 0 8 0 filepl 152 62112 0 62014 90 84 6 14 0 8 1 lockfpl 104 1584 0 1583 1 0 1 1 0 8 0 lockfspl 48 521 0 520 1 0 1 1 0 8 0 sessionpl 112 161 0 151 1 0 1 1 0 8 0 pgrppl 48 193 0 183 1 0 1 1 0 8 0 ucredpl 96 10411 0 10402 1 0 1 1 0 8 0 zombiepl 144 5777 0 5777 2 1 1 1 0 8 1 processpl 896 5808 0 5777 4 0 4 4 0 8 0 procpl 632 16010 0 15970 9 4 5 5 0 8 1 srpgc 64 288 0 288 18 17 1 1 0 8 1 sosppl 128 144 0 144 26 26 0 1 0 8 0 sockpl 384 16454 0 16427 106 98 8 22 0 8 4 mcl64k 65536 53 0 0 4 1 3 3 0 8 0 mcl16k 16384 25 0 0 3 0 3 3 0 8 0 mcl12k 12288 41 0 0 2 0 2 2 0 8 0 mcl9k 9216 24 0 0 2 0 2 2 0 8 0 mcl8k 8192 17 0 0 3 0 3 3 0 8 0 mcl4k 4096 18 0 0 3 0 3 3 0 8 0 mcl2k2 2112 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 143 0 0 16 0 16 16 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 788 0 0 23 0 23 23 0 8 0 bufpl 256 23272 0 16228 441 0 441 441 0 8 0 anonpl 16 886280 0 876896 234 179 55 71 0 124 1 amapchunkpl 152 57595 0 57489 131 125 6 19 0 158 1 amappl16 192 31072 0 30410 266 228 38 47 0 8 0 amappl15 184 706 0 704 12 11 1 1 0 8 0 amappl14 176 1748 0 1742 1 0 1 1 0 8 0 amappl13 168 282 0 282 16 16 0 1 0 8 0 amappl12 160 547 0 544 2 1 1 1 0 8 0 amappl11 152 918 0 902 1 0 1 1 0 8 0 amappl10 144 1103 0 1094 1 0 1 1 0 8 0 amappl9 136 2919 0 2913 1 0 1 1 0 8 0 amappl8 128 2110 0 2044 3 0 3 3 0 8 0 amappl7 120 1648 0 1637 1 0 1 1 0 8 0 amappl6 112 551 0 540 1 0 1 1 0 8 0 amappl5 104 1701 0 1691 1 0 1 1 0 8 0 amappl4 96 5784 0 5754 1 0 1 1 0 8 0 amappl3 88 1317 0 1312 1 0 1 1 0 8 0 amappl2 80 34836 0 34771 3 1 2 3 0 8 0 amappl1 72 172161 0 171738 24 14 10 20 0 8 0 amappl 80 18615 0 18579 2 0 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 64 136 0 7 3 0 3 3 0 8 0 uaddrrnd 24 5792 0 5777 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 5792 0 5777 1 0 1 1 0 8 0 vmmpekpl 168 59858 0 59827 2 0 2 2 0 8 0 vmmpepl 168 809447 0 807649 270 159 111 120 0 357 20 vmsppl 368 5791 0 5777 2 0 2 2 0 8 0 pdppl 4096 11591 0 11554 7 1 6 6 0 8 1 pvpl 32 2250581 0 2238044 466 335 131 171 0 265 0 pmappl 232 5791 0 5777 23 21 2 2 0 8 1 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 646 0 30 18 0 18 18 0 8 0