panic: vrele: v_writecount != 0 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *112587 23432 0 0 0x4000000 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 vrele(fffffd802f2af000) at vrele+0x188 sys/kern/vfs_subr.c:797 diskmapioctl(5a00,c0106477,ffff8000149b6a20,1,ffff800014940780) at diskmapioctl+0x2a8 sys/dev/diskmap.c:140 VOP_IOCTL(fffffd80374133f0,c0106477,ffff8000149b6a20,1,fffffd803f7c6b40,ffff800014940780) at VOP_IOCTL+0x88 sys/kern/vfs_vops.c:290 vn_ioctl(fffffd802f92fcb8,c0106477,ffff8000149b6a20,ffff800014940780) at vn_ioctl+0xb6 sys/kern/vfs_vnops.c:519 sys_ioctl(ffff800014940780,ffff8000149b6b38,ffff8000149b6ba0) at sys_ioctl+0x5b8 syscall(ffff8000149b6c00) at syscall+0x508 Xsyscall(6,0,ffffffffffffff1f,0,3,19b13fb6010) at Xsyscall+0x128 end of kernel end trace frame: 0x19da62e4bb0, count: 6 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 vrele: v_writecount != 0 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 vrele(fffffd802f2af000) at vrele+0x188 sys/kern/vfs_subr.c:797 diskmapioctl(5a00,c0106477,ffff8000149b6a20,1,ffff800014940780) at diskmapioctl+0x2a8 sys/dev/diskmap.c:140 VOP_IOCTL(fffffd80374133f0,c0106477,ffff8000149b6a20,1,fffffd803f7c6b40,ffff800014940780) at VOP_IOCTL+0x88 sys/kern/vfs_vops.c:290 vn_ioctl(fffffd802f92fcb8,c0106477,ffff8000149b6a20,ffff800014940780) at vn_ioctl+0xb6 sys/kern/vfs_vnops.c:519 sys_ioctl(ffff800014940780,ffff8000149b6b38,ffff8000149b6ba0) at sys_ioctl+0x5b8 syscall(ffff8000149b6c00) at syscall+0x508 Xsyscall(6,0,ffffffffffffff1f,0,3,19b13fb6010) at Xsyscall+0x128 end of kernel end trace frame: 0x19da62e4bb0, count: -9 ddb> show registers rdi 0xffffffff8141a407 db_enter+0x17 rsi 0x8cc2 __ALIGN_SIZE+0x7cc2 rbp 0xffff8000149b65e0 rbx 0xffff8000149b6690 rdx 0x8cc3 __ALIGN_SIZE+0x7cc3 rcx 0xffff800016be9000 rax 0xffff800016be9000 r8 0xffff8000149b65a0 r9 0x1 r10 0xffff800000998e80 r11 0xadcdb6d4bf27fb40 r12 0x3000000008 r13 0xffff8000149b65f0 r14 0x100 r15 0x1 rip 0xffffffff8141a408 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000149b65d0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (syz-executor.0) pid=112587 stat=onproc flags process=0 proc=4000000 pri=24, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800014940290,0xffff800014941b50 process=0xffff8000ffff7b10 user=0xffff8000149b1000, vmspace=0xfffffd803f00cee0 estcpu=36, cpticks=3, pctcpu=0.0 user=0, sys=3, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 23432 447876 98074 0 2 0 syz-executor.0 *23432 112587 98074 0 7 0x4000000 syz-executor.0 23432 315992 98074 0 3 0x4000080 nanosleep syz-executor.0 23432 19114 98074 0 2 0x4000000 syz-executor.0 48198 513523 1 0 3 0x100083 ttyin getty 95293 83259 83626 0 2 0x2 syz-executor.1 79068 50081 0 0 3 0x14200 bored sosplice 98074 409738 83626 0 2 0x482 syz-executor.0 83626 485515 61624 0 3 0x82 thrsleep syz-fuzzer 83626 251608 61624 0 2 0x4000482 syz-fuzzer 83626 342353 61624 0 3 0x4000082 thrsleep syz-fuzzer 83626 353134 61624 0 3 0x4000082 thrsleep syz-fuzzer 83626 175856 61624 0 3 0x4000082 thrsleep syz-fuzzer 83626 319014 61624 0 3 0x4000082 kqread syz-fuzzer 83626 361138 61624 0 3 0x4000082 thrsleep syz-fuzzer 83626 117396 61624 0 3 0x4000082 thrsleep syz-fuzzer 61624 8690 36617 0 3 0x10008a pause ksh 36617 51432 43354 0 3 0x92 select sshd 43354 407258 1 0 3 0x80 select sshd 35453 51958 58730 73 2 0x100090 syslogd 58730 329609 1 0 3 0x100082 netio syslogd 67151 438936 1 77 3 0x100090 poll dhclient 73758 222764 1 0 3 0x80 poll dhclient 48588 252196 0 0 2 0x14200 zerothread 48447 40082 0 0 3 0x14200 aiodoned aiodoned 98938 233496 0 0 3 0x14200 syncer update 51008 288634 0 0 3 0x14200 cleaner cleaner 16612 371568 0 0 3 0x14200 reaper reaper 8872 297272 0 0 3 0x14200 pgdaemon pagedaemon 866 296935 0 0 3 0x14200 bored crynlk 69476 272833 0 0 3 0x14200 bored crypto 91173 142015 0 0 3 0x40014200 acpi0 acpi0 14252 487350 0 0 3 0x14200 bored softnet 31041 415972 0 0 3 0x14200 bored systqmp 92696 515667 0 0 3 0x14200 bored systq 47919 8178 0 0 3 0x40014200 bored softclock 49308 104337 0 0 3 0x40014200 idle0 37430 481356 0 0 3 0x14200 bored smr 1 403681 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 9559 6370K 7141K 78643K 25337 0 0 pcb 13 8K 8K 78643K 409 0 0 rtable 117 4K 5K 78643K 1137 0 0 ifaddr 73 16K 17K 78643K 441 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 254 0 0 iov 0 0K 24K 78643K 607 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1205 76K 77K 78643K 6406 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 96 0 0 VM map 2 0K 0K 78643K 2 0 0 sem 12 1K 1K 78643K 14 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 5 13K 25K 78643K 5226 0 0 sigio 1 0K 0K 78643K 112 0 0 proc 41 30K 54K 78643K 1027 0 0 subproc 32 2K 2K 78643K 123 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 466 0 0 in_multi 33 2K 2K 78643K 228 0 0 ether_multi 1 0K 0K 78643K 23 0 0 mrt 0 0K 0K 78643K 17 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 90 397K 397K 78643K 90 0 0 exec 0 0K 1K 78643K 760 0 0 pfkey data 0 0K 0K 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 96 21K 37K 78643K 13262 0 0 UVM aobj 130 4K 4K 78643K 139 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 213 0 0 NDP 17 0K 0K 78643K 123 0 0 temp 206 2728K 2798K 78643K 19480 0 0 kqueue 0 0K 0K 78643K 27 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 18 0 12 1 0 1 1 0 8 0 rtpcb 80 245 0 243 1 0 1 1 0 8 0 rtentry 112 116 0 71 2 0 2 2 0 8 0 unpcb 120 1889 0 1877 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 2842 0 2842 2 2 0 1 0 8 0 tcpcb 544 683 0 679 1 0 1 1 0 8 0 inpcb 280 2109 0 2102 4 3 1 2 0 8 0 nd6 48 21 0 15 1 0 1 1 0 8 0 pkpcb 40 26 0 26 10 9 1 1 0 8 1 swfcl 56 5 0 0 1 0 1 1 0 8 0 ppxss 1128 79 0 79 25 25 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 425 0 234 15 3 12 13 0 8 0 art_table 32 426 0 234 2 0 2 2 0 8 0 art_node 16 102 0 62 1 0 1 1 0 8 0 sysvmsgpl 40 25 0 13 1 0 1 1 0 8 0 semapl 112 12 0 2 1 0 1 1 0 8 0 shmpl 112 137 0 9 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 9973 0 8570 46 0 46 46 0 8 0 ffsino 240 9973 0 8570 84 0 84 84 0 8 0 nchpl 144 17224 0 15593 61 0 61 61 0 8 0 uvmvnodes 72 7766 0 0 142 0 142 142 0 8 0 vnodes 200 7766 0 0 409 0 409 409 0 8 0 namei 1024 54937 0 54937 2 1 1 1 0 8 1 scsiplug 64 5 0 5 4 4 0 1 0 8 0 scxspl 192 54977 0 54977 28 27 1 6 0 8 1 plimitpl 152 410 0 403 1 0 1 1 0 8 0 sigapl 432 5385 0 5372 2 0 2 2 0 8 0 futexpl 56 83507 0 83507 1 0 1 1 0 8 1 knotepl 112 1039 0 1020 1 0 1 1 0 8 0 kqueuepl 104 1201 0 1199 1 0 1 1 0 8 0 pipepl 112 2990 0 2971 5 4 1 2 0 8 0 fdescpl 424 5386 0 5372 2 0 2 2 0 8 0 filepl 120 31877 0 31779 7 3 4 5 0 8 1 lockfpl 104 1691 0 1691 6 5 1 1 0 8 1 lockfspl 48 594 0 594 6 5 1 1 0 8 1 sessionpl 112 25 0 15 1 0 1 1 0 8 0 pgrppl 48 73 0 63 1 0 1 1 0 8 0 ucredpl 96 6366 0 6359 1 0 1 1 0 8 0 zombiepl 144 5372 0 5372 2 1 1 1 0 8 1 processpl 864 5401 0 5372 4 0 4 4 0 8 0 procpl 632 12164 0 12125 4 0 4 4 0 8 0 sosppl 128 60 0 60 15 15 0 1 0 8 0 sockpl 384 4309 0 4288 8 5 3 3 0 8 0 mcl64k 65536 2428 0 2428 212 212 0 33 0 8 0 mcl16k 16384 9 0 9 7 7 0 1 0 8 0 mcl12k 12288 82 0 82 18 17 1 1 0 8 1 mcl9k 9216 85 0 85 20 20 0 1 0 8 0 mcl8k 8192 65 0 65 17 17 0 1 0 8 0 mcl4k 4096 213 0 213 7 6 1 1 0 8 1 mcl2k2 2112 30 0 30 15 15 0 1 0 8 0 mcl2k 2048 60259 0 60200 19 11 8 14 0 8 0 mtagpl 80 319 0 73 7 1 6 6 0 8 0 mbufpl 256 122962 0 122386 141 103 38 52 0 8 0 bufpl 256 22375 0 14612 486 0 486 486 0 8 0 anonpl 16 497066 0 485291 232 167 65 65 0 62 14 amapchunkpl 152 24126 0 24008 82 63 19 19 0 158 13 amappl16 192 29788 0 29147 229 188 41 45 0 8 8 amappl15 184 12 0 11 3 2 1 1 0 8 0 amappl14 176 94 0 89 1 0 1 1 0 8 0 amappl13 168 412 0 412 3 3 0 1 0 8 0 amappl12 160 13 0 12 2 1 1 1 0 8 0 amappl11 152 66 0 55 1 0 1 1 0 8 0 amappl10 144 4781 0 4777 1 0 1 1 0 8 0 amappl9 136 608 0 605 1 0 1 1 0 8 0 amappl8 128 183 0 166 1 0 1 1 0 8 0 amappl7 120 4765 0 4757 1 0 1 1 0 8 0 amappl6 112 55 0 49 1 0 1 1 0 8 0 amappl5 104 228 0 218 1 0 1 1 0 8 0 amappl4 96 5635 0 5610 1 0 1 1 0 8 0 amappl3 88 351 0 341 1 0 1 1 0 8 0 amappl2 80 42260 0 42191 3 1 2 3 0 8 0 amappl1 72 100657 0 100253 25 16 9 19 0 8 0 amappl 80 12532 0 12493 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 dma64 64 259 0 259 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 64 138 0 9 3 0 3 3 0 8 0 uaddrrnd 24 5386 0 5372 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 5386 0 5372 1 0 1 1 0 8 0 vmmpekpl 168 35769 0 35744 2 0 2 2 0 8 0 vmmpepl 168 629262 0 627582 225 135 90 94 0 357 15 vmsppl 272 5385 0 5372 2 1 1 2 0 8 0 pdppl 4096 10779 0 10744 6 1 5 6 0 8 0 pvpl 32 1474372 0 1459507 483 321 162 259 0 265 38 pmappl 200 5385 0 5372 1 0 1 1 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 1005 0 364 21 1 20 20 0 8 0