panic: fifo_badop called Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *245928 64001 32767 0x10 0 1K syz-executor.0 342323 13112 0 0x2 0x4000000 0 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(ffff800022d42f58) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491 VOP_STRATEGY(fffffd807b44bc00) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:727 bwrite(fffffd807b44bc00) at bwrite+0x1b9 sys/kern/vfs_bio.c:738 VOP_BWRITE(fffffd807b44bc00) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:739 ufs_mkdir(ffff800022d431e0) at ufs_mkdir+0x6b7 sys/ufs/ufs/ufs_vnops.c:1250 VOP_MKDIR(fffffd8073419020,ffff800022d43340,ffff800022d43390,ffff800022d43270) at VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 domkdirat(ffff800020a89160,ffffff9c,7f7ffffbd330,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 syscall(ffff800022d43510) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800022d43510) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,88,7f7ffffbd330,88,0,7f7ffffbd354) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbd3a0, 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{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic fifo_badop called ddb{1}> 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(ffff800022d42f58) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491 VOP_STRATEGY(fffffd807b44bc00) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:727 bwrite(fffffd807b44bc00) at bwrite+0x1b9 sys/kern/vfs_bio.c:738 VOP_BWRITE(fffffd807b44bc00) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:739 ufs_mkdir(ffff800022d431e0) at ufs_mkdir+0x6b7 sys/ufs/ufs/ufs_vnops.c:1250 VOP_MKDIR(fffffd8073419020,ffff800022d43340,ffff800022d43390,ffff800022d43270) at VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 domkdirat(ffff800020a89160,ffffff9c,7f7ffffbd330,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 syscall(ffff800022d43510) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800022d43510) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,88,7f7ffffbd330,88,0,7f7ffffbd354) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbd3a0, count: -11 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800022d42e80 rbx 0xffff800022d42f30 rdx 0xffff800020a89160 rcx 0 rax 0 r8 0xffffffff817abe2f kprintf+0x16f r9 0x1 r10 0x25 r11 0xae17a4d3439d9ed1 r12 0x3000000008 r13 0xffff800022d42e90 r14 0x100 r15 0x1 rip 0xffffffff815f6b58 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800022d42e70 ss 0 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=245928 stat=onproc flags process=10 proc=0 pri=17, usrpri=55, nice=20 forw=0xffffffffffffffff, list=0xffff800020a88508,0xffffffff826417a8 process=0xffff800020a8b190 user=0xffff800022d3e000, vmspace=0xfffffd807f00b2e0 estcpu=14, cpticks=0, pctcpu=0.1 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND *64001 245928 14486 32767 7 0x10 syz-executor.0 14486 32164 13112 0 3 0x82 wait syz-executor.0 1422 117279 61939 32767 2 0x10 syz-executor.1 61939 71811 13112 0 3 0x82 wait syz-executor.1 59717 41569 0 0 3 0x14200 bored sosplice 13112 439035 79857 0 3 0x82 thrsleep syz-fuzzer 13112 67247 79857 0 3 0x4000082 nanosleep syz-fuzzer 13112 260486 79857 0 3 0x4000082 thrsleep syz-fuzzer 13112 500068 79857 0 2 0x4000002 syz-fuzzer 13112 263402 79857 0 3 0x4000082 thrsleep syz-fuzzer 13112 342323 79857 0 7 0x4000002 syz-fuzzer 13112 397398 79857 0 3 0x4000082 thrsleep syz-fuzzer 13112 192940 79857 0 3 0x4000082 thrsleep syz-fuzzer 13112 428417 79857 0 3 0x4000082 thrsleep syz-fuzzer 13112 363107 79857 0 3 0x4000082 thrsleep syz-fuzzer 79857 461537 25056 0 3 0x10008a pause ksh 25056 471736 4712 0 3 0x92 select sshd 83393 424234 1 0 3 0x100083 ttyin getty 4712 435707 1 0 3 0x80 select sshd 10767 18266 37199 73 3 0x100090 kqread syslogd 37199 484855 1 0 3 0x100082 netio syslogd 89725 292050 1 77 3 0x100090 poll dhclient 18629 516513 1 0 3 0x80 poll dhclient 92633 499780 0 0 2 0x14200 zerothread 60652 295745 0 0 3 0x14200 aiodoned aiodoned 29056 247715 0 0 3 0x14200 syncer update 92283 2300 0 0 3 0x14200 cleaner cleaner 36285 434566 0 0 3 0x14200 reaper reaper 25110 220964 0 0 3 0x14200 pgdaemon pagedaemon 2086 66718 0 0 3 0x14200 bored crynlk 85268 304196 0 0 3 0x14200 bored crypto 71371 9343 0 0 3 0x40014200 acpi0 acpi0 54236 137534 0 0 3 0x40014200 idle1 6392 480569 0 0 3 0x14200 bored softnet 77760 502393 0 0 3 0x14200 bored systqmp 45477 148435 0 0 3 0x14200 bored systq 58382 490254 0 0 3 0x40014200 bored softclock 34984 111782 0 0 3 0x40014200 idle0 31925 85480 0 0 3 0x14200 bored smr 1 66970 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 64001 (syz-executor.0) thread 0xffff800020a89160 (245928) 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 (0xfffffd807db95b40) #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 (0xfffffd807db95d60) #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 Process 1422 (syz-executor.1) thread 0xffff800020a88018 (117279) exclusive rrwlock inode r = 0 (0xfffffd806b4943d8) #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 vn_closefile+0xc7 vn_close sys/kern/vfs_vnops.c:301 [inline] #5 vn_closefile+0xc7 sys/kern/vfs_vnops.c:613 #6 fdrop+0xc2 sys/kern/kern_descrip.c:1273 #7 closef+0x11d sys/kern/kern_descrip.c:1257 #8 fdrelease+0xba sys/kern/kern_descrip.c:757 #9 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #9 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #10 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9469 6322K 6322K 78643K 15411 0 0 pcb 13 12K 14K 78643K 17 0 0 rtable 117 3K 3K 78643K 39233 0 0 ifaddr 37 22K 28K 78643K 6350 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 1179 0 0 iov 0 0K 32K 78643K 568 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1215 76K 76K 78643K 18489 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 211 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 1454 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 33K 78643K 20719 0 0 sigio 0 0K 0K 78643K 212 0 0 proc 48 50K 83K 78643K 40408 0 0 subproc 34 2K 2K 78643K 16558 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 474 0 0 in_multi 33 2K 2K 78643K 10949 0 0 ether_multi 1 0K 0K 78643K 40 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 102 450K 450K 78643K 102 0 0 exec 0 0K 1K 78643K 13260 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 118 23K 32K 78643K 67171 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 0K 78643K 491 0 0 NDP 5 0K 0K 78643K 2922 0 0 temp 121 3558K 3732K 78643K 154908 0 0 kqueue 0 0K 1K 78643K 970 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 1953 0 1947 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 2539 0 2537 1 0 1 1 0 8 0 rtentry 112 9770 0 9720 2 0 2 2 0 8 0 unpcb 120 4596 0 4587 4 3 1 2 0 8 0 syncache 264 67 0 67 24 24 0 1 0 8 0 tcpqe 32 36 0 36 16 16 0 1 0 8 0 tcpcb 544 2928 0 2924 20 19 1 14 0 8 0 ipq 40 79 0 79 28 28 0 1 0 8 0 ipqe 40 2186 0 2186 28 28 0 1 0 8 0 inpcb 280 10306 0 10299 73 72 1 13 0 8 0 nd6 48 1950 0 1946 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 46391 0 46087 24 5 19 20 0 8 0 art_table 32 46392 0 46087 13 10 3 3 0 8 0 art_node 16 9769 0 9723 1 0 1 1 0 8 0 sysvmsgpl 40 119 0 79 1 0 1 1 0 8 0 semupl 112 5 0 5 1 1 0 1 0 8 0 semapl 112 1452 0 1442 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 9976 0 8563 46 0 46 46 0 8 0 ffsino 272 9976 0 8563 95 0 95 95 0 8 0 nchpl 144 23616 0 22005 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 180915 0 180914 1 0 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 62280 0 62280 45 44 1 7 0 8 1 plimitpl 152 2529 0 2520 1 0 1 1 0 8 0 sigapl 432 17975 0 17961 42 40 2 3 0 8 0 futexpl 56 119440 0 119440 1 0 1 1 0 8 1 knotepl 112 24762 0 24743 42 40 2 6 0 8 1 kqueuepl 104 7756 0 7754 37 35 2 4 0 8 1 pipepl 112 10078 0 10059 6 5 1 2 0 8 0 fdescpl 488 17976 0 17961 4 1 3 3 0 8 1 filepl 152 93330 0 93232 116 109 7 14 0 8 3 lockfpl 104 1480 0 1479 1 0 1 1 0 8 0 lockfspl 48 459 0 458 1 0 1 1 0 8 0 sessionpl 112 989 0 979 1 0 1 1 0 8 0 pgrppl 48 1027 0 1017 1 0 1 1 0 8 0 ucredpl 96 11131 0 11122 1 0 1 1 0 8 0 zombiepl 144 17961 0 17961 1 0 1 1 0 8 1 processpl 896 17992 0 17961 4 0 4 4 0 8 0 procpl 632 27017 0 26977 52 47 5 5 0 8 1 srpgc 64 1942 0 1942 8 7 1 1 0 8 1 sosppl 128 121 0 121 15 15 0 1 0 8 0 sockpl 384 17499 0 17481 105 101 4 22 0 8 1 mcl64k 65536 25 0 0 3 0 3 3 0 8 0 mcl16k 16384 33 0 0 4 1 3 3 0 8 0 mcl12k 12288 49 0 0 2 0 2 2 0 8 0 mcl9k 9216 26 0 0 2 0 2 2 0 8 0 mcl8k 8192 48 0 0 5 2 3 3 0 8 0 mcl4k 4096 39 0 0 4 1 3 3 0 8 0 mcl2k2 2112 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 734 0 0 17 7 10 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 1285 0 0 24 1 23 23 0 8 0 bufpl 256 18899 0 11855 441 0 441 441 0 8 0 anonpl 16 1617781 0 1611455 133 90 43 52 0 124 0 amapchunkpl 152 192850 0 192764 118 109 9 12 0 158 4 amappl16 192 57066 0 56726 177 151 26 34 0 8 0 amappl15 184 1626 0 1625 1 0 1 1 0 8 0 amappl14 176 7846 0 7834 1 0 1 1 0 8 0 amappl13 168 1116 0 1116 43 42 1 1 0 8 1 amappl12 160 1194 0 1185 4 3 1 1 0 8 0 amappl11 152 3973 0 3962 1 0 1 1 0 8 0 amappl10 144 1738 0 1730 1 0 1 1 0 8 0 amappl9 136 14184 0 14177 1 0 1 1 0 8 0 amappl8 128 10368 0 10291 4 1 3 3 0 8 0 amappl7 120 4834 0 4825 1 0 1 1 0 8 0 amappl6 112 1823 0 1804 1 0 1 1 0 8 0 amappl5 104 7850 0 7841 1 0 1 1 0 8 0 amappl4 96 18022 0 17987 1 0 1 1 0 8 0 amappl3 88 2205 0 2200 1 0 1 1 0 8 0 amappl2 80 66022 0 65959 3 1 2 3 0 8 0 amappl1 72 559823 0 559410 56 47 9 20 0 8 0 amappl 80 42166 0 42133 1 0 1 1 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 17976 0 17961 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 17976 0 17961 1 0 1 1 0 8 0 vmmpekpl 168 155118 0 155086 3 0 3 3 0 8 0 vmmpepl 168 2257592 0 2256092 358 270 88 97 0 357 12 vmsppl 368 17975 0 17961 2 0 2 2 0 8 0 pdppl 4096 35959 0 35922 7 1 6 6 0 8 1 pvpl 32 5881544 0 5871912 444 332 112 135 0 265 0 pmappl 232 17975 0 17961 19 17 2 2 0 8 1 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 653 0 39 18 0 18 18 0 8 0