panic: fifo_badop called Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *348955 63970 32767 0x10 0 1K syz-executor.1 19221 39560 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(ffff800020b49608) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491 VOP_STRATEGY(fffffd806810e800) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:727 bwrite(fffffd806810e800) at bwrite+0x1b9 sys/kern/vfs_bio.c:738 VOP_BWRITE(fffffd806810e800) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:739 ufs_mkdir(ffff800020b49890) at ufs_mkdir+0x6b7 sys/ufs/ufs/ufs_vnops.c:1250 VOP_MKDIR(fffffd807ca4f840,ffff800020b499f0,ffff800020b49a40,ffff800020b49920) at VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 domkdirat(ffff800020a88ee8,ffffff9c,7f7fffff9420,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 syscall(ffff800020b49bc0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020b49bc0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,88,7f7fffff9420,88,0,7f7fffff9444) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff9490, 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(ffff800020b49608) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491 VOP_STRATEGY(fffffd806810e800) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:727 bwrite(fffffd806810e800) at bwrite+0x1b9 sys/kern/vfs_bio.c:738 VOP_BWRITE(fffffd806810e800) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:739 ufs_mkdir(ffff800020b49890) at ufs_mkdir+0x6b7 sys/ufs/ufs/ufs_vnops.c:1250 VOP_MKDIR(fffffd807ca4f840,ffff800020b499f0,ffff800020b49a40,ffff800020b49920) at VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 domkdirat(ffff800020a88ee8,ffffff9c,7f7fffff9420,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 syscall(ffff800020b49bc0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020b49bc0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,88,7f7fffff9420,88,0,7f7fffff9444) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff9490, count: -11 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020b49530 rbx 0xffff800020b495e0 rdx 0xffff800020a88ee8 rcx 0 rax 0 r8 0xffffffff813e1fff kprintf+0x16f r9 0x1 r10 0x25 r11 0x9bdb1327df4b87bb r12 0x3000000008 r13 0xffff800020b49540 r14 0x100 r15 0x1 rip 0xffffffff81b7ee58 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020b49520 ss 0 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=348955 stat=onproc flags process=10 proc=0 pri=17, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff800020a893d8,0xffffffff8265b158 process=0xffff800020adce00 user=0xffff800020b44000, vmspace=0xfffffd807f00a5c0 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND *63970 348955 8247 32767 7 0x10 syz-executor.1 8247 469772 39560 0 3 0x82 wait syz-executor.1 25768 307127 63718 32767 2 0x10 syz-executor.0 63718 139964 39560 0 3 0x82 wait syz-executor.0 79210 294314 0 0 3 0x14200 bored sosplice 39560 114781 18705 0 3 0x82 thrsleep syz-fuzzer 39560 434301 18705 0 3 0x4000082 nanosleep syz-fuzzer 39560 234496 18705 0 3 0x4000082 thrsleep syz-fuzzer 39560 19221 18705 0 7 0x4000002 syz-fuzzer 39560 324556 18705 0 3 0x4000082 thrsleep syz-fuzzer 39560 404017 18705 0 3 0x4000082 thrsleep syz-fuzzer 39560 387693 18705 0 3 0x4000082 thrsleep syz-fuzzer 39560 41747 18705 0 3 0x4000082 thrsleep syz-fuzzer 39560 477725 18705 0 3 0x4000082 thrsleep syz-fuzzer 39560 104303 18705 0 2 0x4000002 syz-fuzzer 18705 192387 94783 0 3 0x10008a pause ksh 94783 25623 50687 0 3 0x92 select sshd 6150 199155 1 0 3 0x100083 ttyin getty 50687 440743 1 0 3 0x80 select sshd 88815 284402 12157 73 3 0x100090 kqread syslogd 12157 505600 1 0 3 0x100082 netio syslogd 59494 385224 1 77 3 0x100090 poll dhclient 53820 453892 1 0 3 0x80 poll dhclient 81053 251047 0 0 3 0x14200 pgzero zerothread 33456 412243 0 0 3 0x14200 aiodoned aiodoned 86692 77881 0 0 3 0x14200 syncer update 57886 463666 0 0 3 0x14200 cleaner cleaner 25805 118187 0 0 3 0x14200 reaper reaper 58744 50948 0 0 3 0x14200 pgdaemon pagedaemon 37884 47128 0 0 3 0x14200 bored crynlk 4468 194621 0 0 3 0x14200 bored crypto 84252 370322 0 0 3 0x40014200 acpi0 acpi0 13039 121443 0 0 3 0x40014200 idle1 37367 463450 0 0 3 0x14200 bored softnet 6301 82007 0 0 3 0x14200 bored systqmp 66326 390171 0 0 3 0x14200 bored systq 33635 158387 0 0 3 0x40014200 bored softclock 47414 66255 0 0 3 0x40014200 idle0 79322 511180 0 0 3 0x14200 bored smr 1 81643 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 63970 (syz-executor.1) thread 0xffff800020a88ee8 (348955) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8265aa28) #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 (0xfffffd8067822d60) #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 (0xfffffd80678224e0) #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 25768 (syz-executor.0) thread 0xffff800020a89160 (307127) exclusive rrwlock inode r = 0 (0xfffffd80678225f0) #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 9471 6323K 6323K 78643K 10913 0 0 pcb 13 12K 14K 78643K 17 0 0 rtable 105 3K 3K 78643K 3172 0 0 ifaddr 35 11K 12K 78643K 469 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 153 0 0 iov 0 0K 32K 78643K 462 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1215 76K 76K 78643K 3039 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 47 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 1593 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 33K 78643K 3581 0 0 sigio 0 0K 0K 78643K 52 0 0 proc 48 50K 83K 78643K 3636 0 0 subproc 34 2K 2K 78643K 1241 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 352 0 0 in_multi 33 2K 2K 78643K 872 0 0 ether_multi 1 0K 0K 78643K 6 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 1374 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 126 23K 32K 78643K 13439 0 0 UVM aobj 130 6K 6K 78643K 134 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 204 0 0 NDP 7 0K 0K 78643K 222 0 0 temp 121 3558K 3628K 78643K 19074 0 0 kqueue 0 0K 0K 78643K 39 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 64 154 0 148 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 434 0 432 1 0 1 1 0 8 0 rtentry 112 761 0 717 2 0 2 2 0 8 0 unpcb 120 2113 0 2103 5 4 1 2 0 8 0 syncache 264 24 0 24 11 11 0 1 0 8 0 tcpqe 32 7 0 7 5 5 0 1 0 8 0 tcpcb 544 2407 0 2403 30 22 8 12 0 8 7 ipq 40 44 0 44 14 14 0 1 0 8 0 ipqe 40 1484 0 1484 14 14 0 1 0 8 0 inpcb 280 4711 0 4702 52 44 8 13 0 8 7 ip6q 72 3 0 3 2 2 0 1 0 8 0 ip6af 40 141 0 141 2 2 0 1 0 8 0 nd6 48 146 0 142 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 3343 0 3128 14 0 14 14 0 8 0 art_table 32 3344 0 3128 2 0 2 2 0 8 0 art_node 16 760 0 720 1 0 1 1 0 8 0 sysvmsgpl 40 68 0 41 1 0 1 1 0 8 0 semupl 112 5 0 5 1 1 0 1 0 8 0 semapl 112 1591 0 1581 1 0 1 1 0 8 0 shmpl 112 132 0 4 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 5105 0 3697 46 0 46 46 0 8 0 ffsino 272 5105 0 3697 95 0 95 95 0 8 0 nchpl 144 9341 0 7737 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 57844 0 57843 3 2 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 26488 0 26488 27 26 1 7 0 8 1 plimitpl 152 533 0 524 1 0 1 1 0 8 0 sigapl 432 3539 0 3525 5 3 2 3 0 8 0 futexpl 56 71469 0 71469 3 2 1 1 0 8 1 knotepl 112 2555 0 2536 5 4 1 3 0 8 0 kqueuepl 104 1923 0 1921 7 4 3 4 0 8 2 pipepl 112 4940 0 4921 14 13 1 2 0 8 0 fdescpl 488 3540 0 3525 3 0 3 3 0 8 0 filepl 152 44688 0 44590 54 43 11 14 0 8 7 lockfpl 104 1179 0 1178 1 0 1 1 0 8 0 lockfspl 48 325 0 324 1 0 1 1 0 8 0 sessionpl 112 88 0 78 1 0 1 1 0 8 0 pgrppl 48 108 0 98 1 0 1 1 0 8 0 ucredpl 96 16882 0 16873 1 0 1 1 0 8 0 zombiepl 144 3525 0 3525 2 1 1 1 0 8 1 processpl 896 3556 0 3525 4 0 4 4 0 8 0 procpl 632 9656 0 9616 11 6 5 5 0 8 1 srpgc 64 142 0 142 15 14 1 1 0 8 1 sosppl 128 57 0 57 14 14 0 1 0 8 0 sockpl 384 7309 0 7290 80 70 10 22 0 8 7 mcl64k 65536 30 0 0 4 1 3 3 0 8 0 mcl16k 16384 16 0 0 2 0 2 2 0 8 0 mcl12k 12288 25 0 0 2 0 2 2 0 8 0 mcl9k 9216 20 0 0 2 0 2 2 0 8 0 mcl8k 8192 17 0 0 3 0 3 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 5 0 0 1 0 1 1 0 8 0 mcl2k 2048 159 0 0 19 0 19 19 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 630 0 0 21 0 21 21 0 8 0 bufpl 256 10999 0 3955 441 0 441 441 0 8 0 anonpl 16 478468 0 469309 154 96 58 65 0 124 7 amapchunkpl 152 32380 0 32276 62 56 6 19 0 158 0 amappl16 192 17737 0 17090 181 139 42 46 0 8 8 amappl15 184 371 0 371 7 7 0 1 0 8 0 amappl14 176 773 0 768 1 0 1 1 0 8 0 amappl13 168 323 0 322 10 9 1 1 0 8 0 amappl12 160 275 0 272 1 0 1 1 0 8 0 amappl11 152 624 0 613 1 0 1 1 0 8 0 amappl10 144 903 0 902 1 0 1 1 0 8 0 amappl9 136 1759 0 1752 1 0 1 1 0 8 0 amappl8 128 1181 0 1119 4 1 3 3 0 8 0 amappl7 120 1203 0 1194 1 0 1 1 0 8 0 amappl6 112 484 0 469 1 0 1 1 0 8 0 amappl5 104 829 0 819 1 0 1 1 0 8 0 amappl4 96 3729 0 3700 1 0 1 1 0 8 0 amappl3 88 644 0 637 1 0 1 1 0 8 0 amappl2 80 22281 0 22217 3 1 2 3 0 8 0 amappl1 72 104396 0 103986 24 14 10 20 0 8 0 amappl 80 11022 0 10987 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 64 133 0 4 3 0 3 3 0 8 0 uaddrrnd 24 3540 0 3525 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3540 0 3525 1 0 1 1 0 8 0 vmmpekpl 168 41230 0 41200 2 0 2 2 0 8 0 vmmpepl 168 484588 0 482827 221 111 110 119 0 357 22 vmsppl 368 3539 0 3525 2 0 2 2 0 8 0 pdppl 4096 7087 0 7050 6 0 6 6 0 8 1 pvpl 32 1239771 0 1227480 347 200 147 160 0 265 21 pmappl 232 3539 0 3525 10 8 2 2 0 8 1 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 649 0 27 18 0 18 18 0 8 0