panic: vrele: v_writecount != 0 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *429714 44852 0 0x2 0x4000000 0 syz-executor0213 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(fffffd803b532710) at vrele+0x188 sys/kern/vfs_subr.c:797 diskmapioctl(5a00,c0106477,ffff80001497fea0,1,ffff8000ffff5648) at diskmapioctl+0x2a8 sys/dev/diskmap.c:140 VOP_IOCTL(fffffd80374158a0,c0106477,ffff80001497fea0,1,fffffd803f7c6ae0,ffff8000ffff5648) at VOP_IOCTL+0x88 sys/kern/vfs_vops.c:290 vn_ioctl(fffffd8036535080,c0106477,ffff80001497fea0,ffff8000ffff5648) at vn_ioctl+0xb6 sys/kern/vfs_vnops.c:519 sys_ioctl(ffff8000ffff5648,ffff80001497ffb8,ffff800014980020) at sys_ioctl+0x5b8 syscall(ffff800014980080) at syscall+0x508 Xsyscall(6,0,509131d80c8,0,509131d80a8,509131d80a0) at Xsyscall+0x128 end of kernel end trace frame: 0x50bab258d20, 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(fffffd803b532710) at vrele+0x188 sys/kern/vfs_subr.c:797 diskmapioctl(5a00,c0106477,ffff80001497fea0,1,ffff8000ffff5648) at diskmapioctl+0x2a8 sys/dev/diskmap.c:140 VOP_IOCTL(fffffd80374158a0,c0106477,ffff80001497fea0,1,fffffd803f7c6ae0,ffff8000ffff5648) at VOP_IOCTL+0x88 sys/kern/vfs_vops.c:290 vn_ioctl(fffffd8036535080,c0106477,ffff80001497fea0,ffff8000ffff5648) at vn_ioctl+0xb6 sys/kern/vfs_vnops.c:519 sys_ioctl(ffff8000ffff5648,ffff80001497ffb8,ffff800014980020) at sys_ioctl+0x5b8 syscall(ffff800014980080) at syscall+0x508 Xsyscall(6,0,509131d80c8,0,509131d80a8,509131d80a0) at Xsyscall+0x128 end of kernel end trace frame: 0x50bab258d20, count: -9 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001497fa60 rbx 0xffff80001497fb10 rdx 0x2 rcx 0x1 rax 0x1 r8 0xffff80001497fa20 r9 0x1 r10 0x5582f37ff1e16aa8 r11 0xba385b527345ccae r12 0x3000000008 r13 0xffff80001497fa70 r14 0x100 r15 0x1 rip 0xffffffff8141a408 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001497fa50 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (syz-executor0213) pid=429714 stat=onproc flags process=2 proc=4000000 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffff5b38,0xffff8000ffff4020 process=0xffff800014942018 user=0xffff80001497b000, vmspace=0xfffffd803f00c220 estcpu=0, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 44852 35757 1804 0 2 0x2 syz-executor0213 *44852 429714 1804 0 7 0x4000002 syz-executor0213 44852 101060 1804 0 2 0x4000002 syz-executor0213 1804 210316 54369 0 3 0x10008a pause ksh 54369 107265 59454 0 3 0x92 select sshd 20252 105870 1 0 3 0x100083 ttyin getty 59454 328956 1 0 3 0x80 select sshd 29507 288062 52125 73 2 0x100090 syslogd 52125 459546 1 0 3 0x100082 netio syslogd 20059 343245 1 77 3 0x100090 poll dhclient 32781 124896 1 0 3 0x80 poll dhclient 77079 320766 0 0 2 0x14200 zerothread 52403 171623 0 0 3 0x14200 aiodoned aiodoned 16238 196056 0 0 3 0x14200 syncer update 37961 393319 0 0 3 0x14200 cleaner cleaner 89618 240927 0 0 3 0x14200 reaper reaper 68647 214 0 0 3 0x14200 pgdaemon pagedaemon 52448 173219 0 0 3 0x14200 bored crynlk 12848 441366 0 0 3 0x14200 bored crypto 85245 302917 0 0 3 0x40014200 acpi0 acpi0 15503 468649 0 0 3 0x14200 bored softnet 45423 405801 0 0 3 0x14200 bored systqmp 34818 509738 0 0 3 0x14200 bored systq 10821 221791 0 0 3 0x40014200 bored softclock 39128 99366 0 0 3 0x40014200 idle0 90799 31366 0 0 3 0x14200 bored smr 1 507578 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 9429 6308K 6308K 78643K 10522 0 0 pcb 13 8K 8K 78643K 13 0 0 rtable 61 1K 2K 78643K 115 0 0 ifaddr 21 7K 7K 78643K 21 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 13 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1181 74K 74K 78643K 1186 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 1K 78643K 2 0 0 VM map 2 0K 0K 78643K 2 0 0 sem 2 0K 0K 78643K 2 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 1 0K 0K 78643K 1 0 0 proc 40 30K 38K 78643K 257 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 in_multi 11 0K 0K 78643K 11 0 0 ether_multi 1 0K 0K 78643K 1 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 18 79K 79K 78643K 18 0 0 exec 0 0K 1K 78643K 152 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 58 3K 3K 78643K 706 0 0 UVM aobj 2 2K 2K 78643K 2 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 NDP 3 0K 0K 78643K 3 0 0 temp 30 2707K 2771K 78643K 1716 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 2 0 0 1 0 1 1 0 8 0 rtpcb 80 15 0 13 1 0 1 1 0 8 0 rtentry 112 23 0 1 1 0 1 1 0 8 0 unpcb 120 29 0 19 1 0 1 1 0 8 0 syncache 264 5 0 5 1 0 1 1 0 8 1 tcpcb 544 8 0 5 1 0 1 1 0 8 0 inpcb 280 22 0 16 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 97 0 0 7 0 7 7 0 8 0 art_table 32 98 0 0 1 0 1 1 0 8 0 art_node 16 22 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1393 0 17 45 0 45 45 0 8 0 ffsino 240 1393 0 17 81 0 81 81 0 8 0 nchpl 144 1578 0 43 57 0 57 57 0 8 0 uvmvnodes 72 1402 0 0 26 0 26 26 0 8 0 vnodes 200 1402 0 0 74 0 74 74 0 8 0 namei 1024 3368 0 3368 2 1 1 1 0 8 1 scxspl 192 2266 0 2266 2 1 1 2 0 8 1 plimitpl 152 13 0 8 1 0 1 1 0 8 0 sigapl 432 176 0 166 2 0 2 2 0 8 0 futexpl 56 4 0 4 1 0 1 1 0 8 1 knotepl 112 5 0 0 1 0 1 1 0 8 0 kqueuepl 104 1 0 0 1 0 1 1 0 8 0 pipepl 112 118 0 111 2 1 1 1 0 8 0 fdescpl 424 177 0 166 2 0 2 2 0 8 0 filepl 120 840 0 796 2 0 2 2 0 8 0 lockfpl 104 6 0 6 1 1 0 1 0 8 0 lockfspl 48 3 0 3 1 1 0 1 0 8 0 sessionpl 112 17 0 9 1 0 1 1 0 8 0 pgrppl 48 17 0 9 1 0 1 1 0 8 0 ucredpl 96 47 0 40 1 0 1 1 0 8 0 zombiepl 144 166 0 166 2 1 1 1 0 8 1 processpl 864 191 0 166 4 0 4 4 0 8 0 procpl 632 193 0 166 3 0 3 3 0 8 0 sockpl 384 66 0 48 2 0 2 2 0 8 0 mcl4k 4096 10 0 10 1 0 1 1 0 8 1 mcl2k 2048 6072 0 6044 6 0 6 6 0 8 2 mtagpl 80 2 0 2 1 1 0 1 0 8 0 mbufpl 256 10382 0 10339 5 1 4 4 0 8 0 bufpl 256 2078 0 262 114 0 114 114 0 8 0 anonpl 16 17986 0 16794 8 2 6 7 0 62 1 amapchunkpl 152 480 0 441 2 0 2 2 0 158 0 amappl16 192 73 0 66 1 0 1 1 0 8 0 amappl14 176 37 0 33 1 0 1 1 0 8 0 amappl12 160 9 0 9 1 0 1 1 0 8 1 amappl11 152 36 0 25 1 0 1 1 0 8 0 amappl10 144 44 0 44 2 1 1 1 0 8 1 amappl9 136 363 0 362 1 0 1 1 0 8 0 amappl8 128 84 0 79 1 0 1 1 0 8 0 amappl7 120 18 0 16 1 0 1 1 0 8 0 amappl6 112 43 0 39 1 0 1 1 0 8 0 amappl5 104 189 0 178 1 0 1 1 0 8 0 amappl4 96 403 0 378 1 0 1 1 0 8 0 amappl3 88 147 0 136 1 0 1 1 0 8 0 amappl2 80 720 0 664 3 1 2 2 0 8 0 amappl1 72 12015 0 11615 16 8 8 16 0 8 0 amappl 80 366 0 345 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 1 0 0 1 0 1 1 0 8 0 uaddrrnd 24 177 0 166 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 177 0 166 1 0 1 1 0 8 0 vmmpekpl 168 5316 0 5300 1 0 1 1 0 8 0 vmmpepl 168 25741 0 24936 48 12 36 48 0 357 1 vmsppl 272 176 0 166 1 0 1 1 0 8 0 pdppl 4096 361 0 332 5 0 5 5 0 8 0 pvpl 32 71246 0 68431 30 4 26 26 0 265 3 pmappl 200 176 0 166 1 0 1 1 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 229 0 4 7 0 7 7 0 8 0