panic: vrele: v_writecount != 0
Stopped at db_enter+0x18: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
*429314 967 0 0 0x4000000 0K syz-executor.1
512053 17256 0 0 0 1 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(fffffd807e114cd0) at vrele+0x188 sys/kern/vfs_subr.c:797
diskmapioctl(5a00,c0106477,ffff800020c19300,1,ffff800020b50290) at diskmapioctl+0x2a8 sys/dev/diskmap.c:140
VOP_IOCTL(fffffd806fac68a0,c0106477,ffff800020c19300,1,fffffd807f7c6b40,ffff800020b50290) at VOP_IOCTL+0x88 sys/kern/vfs_vops.c:290
vn_ioctl(fffffd80682160b0,c0106477,ffff800020c19300,ffff800020b50290) at vn_ioctl+0xb6 sys/kern/vfs_vnops.c:519
sys_ioctl(ffff800020b50290,ffff800020c19418,ffff800020c19480) at sys_ioctl+0x5b8
syscall(ffff800020c194f0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline]
syscall(ffff800020c194f0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555
Xsyscall(6,0,ffffffffffffff1f,0,3,f71788d2010) at Xsyscall+0x128
end of kernel
end trace frame: 0xf73ceb37d10, 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{0}>
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
vrele: v_writecount != 0
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
vrele(fffffd807e114cd0) at vrele+0x188 sys/kern/vfs_subr.c:797
diskmapioctl(5a00,c0106477,ffff800020c19300,1,ffff800020b50290) at diskmapioctl+0x2a8 sys/dev/diskmap.c:140
VOP_IOCTL(fffffd806fac68a0,c0106477,ffff800020c19300,1,fffffd807f7c6b40,ffff800020b50290) at VOP_IOCTL+0x88 sys/kern/vfs_vops.c:290
vn_ioctl(fffffd80682160b0,c0106477,ffff800020c19300,ffff800020b50290) at vn_ioctl+0xb6 sys/kern/vfs_vnops.c:519
sys_ioctl(ffff800020b50290,ffff800020c19418,ffff800020c19480) at sys_ioctl+0x5b8
syscall(ffff800020c194f0) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline]
syscall(ffff800020c194f0) at syscall+0x552 sys/arch/amd64/amd64/trap.c:555
Xsyscall(6,0,ffffffffffffff1f,0,3,f71788d2010) at Xsyscall+0x128
end of kernel
end trace frame: 0xf73ceb37d10, count: -9
ddb{0}> show registers
rdi 0xffffffff81dcdf97 db_enter+0x17
rsi 0x66b9 __ALIGN_SIZE+0x56b9
rbp 0xffff800020c18ec0
rbx 0xffff800020c18f70
rdx 0x66ba __ALIGN_SIZE+0x56ba
rcx 0xffff80002141c000
rax 0xffff80002141c000
r8 0xffffffff81386d93 kprintf+0x173
r9 0x1
r10 0x25
r11 0xb3ffb2db4ed90bf5
r12 0x3000000008
r13 0xffff800020c18ed0
r14 0x100
r15 0x1
rip 0xffffffff81dcdf98 db_enter+0x18
cs 0x8
rflags 0x246
rsp 0xffff800020c18eb0
ss 0x10
db_enter+0x18: addq $0x8,%rsp
ddb{0}> show proc
PROC (syz-executor.1) pid=429314 stat=onproc
flags process=0 proc=4000000<THREAD>
pri=24, usrpri=86, nice=20
forw=0xffffffffffffffff, list=0xffff800020b50780,0xffff800020b51b50
process=0xffff800020aebc08 user=0xffff800020c14000, vmspace=0xfffffd807f00b450
estcpu=36, cpticks=2, pctcpu=0.0
user=0, sys=2, intr=0
ddb{0}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
967 214250 35404 0 2 0 syz-executor.1
* 967 429314 35404 0 7 0x4000000 syz-executor.1
967 228393 35404 0 2 0x4000000 syz-executor.1
17256 512053 54673 0 7 0 syz-executor.0
17256 192131 54673 0 3 0x4000080 poll syz-executor.0
17256 386215 54673 0 3 0x4000080 poll syz-executor.0
50580 173816 1 0 3 0x100083 ttyin getty
35404 68327 52369 0 2 0x482 syz-executor.1
38568 244336 0 0 3 0x14200 bored sosplice
54673 315778 52369 0 2 0x482 syz-executor.0
52369 380015 84603 0 3 0x82 thrsleep syz-fuzzer
52369 273770 84603 0 3 0x4000082 thrsleep syz-fuzzer
52369 460350 84603 0 3 0x4000082 thrsleep syz-fuzzer
52369 20315 84603 0 3 0x4000082 thrsleep syz-fuzzer
52369 305649 84603 0 3 0x4000082 kqread syz-fuzzer
52369 325617 84603 0 3 0x4000082 thrsleep syz-fuzzer
52369 343676 84603 0 3 0x4000082 thrsleep syz-fuzzer
52369 109405 84603 0 3 0x4000082 thrsleep syz-fuzzer
52369 335620 84603 0 3 0x4000082 thrsleep syz-fuzzer
52369 389538 84603 0 3 0x4000082 thrsleep syz-fuzzer
84603 127984 10078 0 3 0x10008a pause ksh
10078 231329 53267 0 3 0x92 select sshd
53267 163016 1 0 3 0x80 select sshd
8227 325218 22237 74 3 0x100092 bpf pflogd
22237 47418 1 0 3 0x80 netio pflogd
6635 207493 62390 73 2 0x100090 syslogd
62390 89275 1 0 3 0x100082 netio syslogd
96676 324604 1 77 3 0x100090 poll dhclient
44282 82592 1 0 3 0x80 poll dhclient
7031 378251 0 0 2 0x14200 zerothread
36929 471381 0 0 3 0x14200 aiodoned aiodoned
2319 293027 0 0 3 0x14200 syncer update
59857 325044 0 0 3 0x14200 cleaner cleaner
88054 32814 0 0 3 0x14200 reaper reaper
68547 273547 0 0 3 0x14200 pgdaemon pagedaemon
90272 255975 0 0 3 0x14200 bored crynlk
66463 257798 0 0 3 0x14200 bored crypto
94966 492658 0 0 3 0x40014200 acpi0 acpi0
99221 174073 0 0 3 0x40014200 idle1
21816 4608 0 0 3 0x14200 bored softnet
75433 181531 0 0 3 0x14200 bored systqmp
23151 174905 0 0 3 0x14200 bored systq
43543 385545 0 0 3 0x40014200 bored softclock
64842 501560 0 0 3 0x40014200 idle0
97472 200704 0 0 3 0x14200 bored smr
1 509244 0 0 3 0x82 wait init
0 0 -1 0 3 0x10200 scheduler swapper
ddb{0}> show all locks
Process 967 (syz-executor.1) thread 0xffff800020b50290 (429314)
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8238f2b8)
#0 witness_lock+0x52e sys/kern/subr_witness.c:1163
#1 __mp_acquire_count+0x51 sys/kern/kern_lock.c:227
#2 mi_switch+0x38f sys/kern/sched_bsd.c:441
#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 fifo_open+0x3b6 sys/miscfs/fifofs/fifo_vnops.c:194
#6 VOP_OPEN+0x6a sys/kern/vfs_vops.c:153
#7 vn_open+0x495 sys/kern/vfs_vnops.c:174
#8 diskmapioctl+0x1ba sys/dev/diskmap.c:89
#9 VOP_IOCTL+0x88 sys/kern/vfs_vops.c:290
#10 vn_ioctl+0xb6 sys/kern/vfs_vnops.c:519
#11 sys_ioctl+0x5b8
#12 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline]
#12 syscall+0x552 sys/arch/amd64/amd64/trap.c:555
#13 Xsyscall+0x128
ddb{0}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim
devbuf 9563 6433K 7460K 78643K 16866 0 0
pcb 13 8K 8K 78643K 140 0 0
rtable 111 4K 4K 78643K 1011 0 0
ifaddr 73 18K 19K 78643K 450 0 0
counters 39 33K 33K 78643K 39 0 0
ioctlops 0 0K 4K 78643K 1563 0 0
iov 0 0K 20K 78643K 155 0 0
mount 1 1K 1K 78643K 1 0 0
vnodes 1220 77K 77K 78643K 3861 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 28 0 0
VM map 2 1K 1K 78643K 2 0 0
sem 12 0K 1K 78643K 964 0 0
dirhash 12 2K 2K 78643K 12 0 0
ACPI 1808 196K 290K 78643K 12765 0 0
file desc 6 17K 25K 78643K 2879 0 0
sigio 0 0K 0K 78643K 10 0 0
proc 54 51K 83K 78643K 640 0 0
subproc 32 2K 2K 78643K 51 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 174 0 0
in_multi 33 2K 2K 78643K 107 0 0
ether_multi 1 0K 0K 78643K 11 0 0
mrt 0 0K 0K 78643K 14 0 0
ISOFS mount 1 32K 32K 78643K 1 0 0
MSDOSFS mount 1 16K 16K 78643K 1 0 0
ttys 78 344K 344K 78643K 78 0 0
exec 0 0K 1K 78643K 357 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 99 21K 30K 78643K 9220 0 0
UVM aobj 76 5K 5K 78643K 89 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 118 0 0
NDP 17 0K 0K 78643K 138 0 0
temp 207 2748K 2820K 78643K 11910 0 0
kqueue 0 0K 0K 78643K 22 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 8 0 2 1 0 1 1 0 8 0
plcache 128 20 0 0 1 0 1 1 0 8 0
rtpcb 80 77 0 75 1 0 1 1 0 8 0
rtentry 112 59 0 15 2 0 2 2 0 8 0
unpcb 120 492 0 480 1 0 1 1 0 8 0
syncache 264 4 0 4 1 1 0 1 0 8 0
tcpqe 32 9984 0 9984 3 3 0 2 0 8 0
tcpcb 544 275 0 271 1 0 1 1 0 8 0
inpcb 280 741 0 734 1 0 1 1 0 8 0
rttmr 72 3 0 3 3 3 0 1 0 8 0
nd6 48 9 0 3 1 0 1 1 0 8 0
pkpcb 40 4 0 4 1 1 0 1 0 8 0
swfcl 56 2 0 0 1 0 1 1 0 8 0
ppxss 1128 25 0 25 6 6 0 1 0 8 0
pffrag 232 3 0 3 2 2 0 1 0 482 0
pffrnode 88 3 0 3 2 2 0 1 0 8 0
pffrent 40 8 0 8 2 2 0 1 0 8 0
pfosfp 40 846 0 423 5 0 5 5 0 8 0
pfosfpen 112 1428 0 714 21 0 21 21 0 8 0
pfstitem 24 40 0 36 1 0 1 1 0 8 0
pfstkey 112 40 0 36 1 0 1 1 0 8 0
pfstate 328 40 0 36 2 1 1 2 0 8 0
pfrule 1360 21 0 16 2 1 1 2 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 235 0 44 13 1 12 12 0 8 0
art_table 32 236 0 44 2 0 2 2 0 8 0
art_node 16 58 0 18 1 0 1 1 0 8 0
sysvmsgpl 40 24 0 16 1 0 1 1 0 8 0
semapl 112 950 0 940 1 0 1 1 0 8 0
shmpl 112 87 0 13 3 0 3 3 0 8 0
dirhash 1024 17 0 0 3 0 3 3 0 8 0
dino1pl 128 7392 0 5974 47 0 47 47 0 8 0
ffsino 272 7392 0 5974 96 0 96 96 0 8 0
nchpl 144 11258 0 9618 62 0 62 62 0 8 0
uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0
vnodes 200 5926 0 0 312 0 312 312 0 8 0
namei 1024 34683 0 34683 2 1 1 1 0 8 1
percpumem 16 30 0 0 1 0 1 1 0 8 0
scsiplug 64 54 0 54 2 1 1 1 0 8 1
scxspl 192 31191 0 31191 15 14 1 6 0 8 1
plimitpl 152 153 0 145 1 0 1 1 0 8 0
sigapl 432 3077 0 3061 3 1 2 3 0 8 0
futexpl 56 37143 0 37143 1 0 1 1 0 8 1
knotepl 112 440 0 421 1 0 1 1 0 8 0
kqueuepl 104 551 0 549 1 0 1 1 0 8 0
pipepl 112 1130 0 1111 3 2 1 2 0 8 0
fdescpl 488 3078 0 3061 3 0 3 3 0 8 0
filepl 152 15166 0 15064 7 2 5 5 0 8 1
lockfpl 104 2107 0 2107 4 4 0 1 0 8 0
lockfspl 48 969 0 969 4 4 0 1 0 8 0
sessionpl 112 20 0 9 1 0 1 1 0 8 0
pgrppl 48 38 0 27 1 0 1 1 0 8 0
ucredpl 96 1992 0 1983 1 0 1 1 0 8 0
zombiepl 144 3061 0 3061 2 1 1 1 0 8 1
processpl 896 3094 0 3061 4 0 4 4 0 8 0
procpl 632 8389 0 8343 11 6 5 5 0 8 1
srpgc 64 5 0 5 3 3 0 1 0 8 0
sosppl 128 22 0 22 4 4 0 1 0 8 0
sockpl 384 1332 0 1311 7 4 3 3 0 8 0
mcl64k 65536 9 0 0 2 0 2 2 0 8 0
mcl16k 16384 2 0 0 1 0 1 1 0 8 0
mcl12k 12288 19 0 0 2 0 2 2 0 8 0
mcl9k 9216 10 0 0 1 0 1 1 0 8 0
mcl8k 8192 33 0 0 5 2 3 3 0 8 0
mcl4k 4096 8 0 0 1 0 1 1 0 8 0
mcl2k2 2112 4 0 0 1 0 1 1 0 8 0
mcl2k 2048 265 0 0 32 6 26 32 0 8 0
mtagpl 80 20 0 0 1 0 1 1 0 8 0
mbufpl 256 336 0 0 17 1 16 17 0 8 0
bufpl 256 12198 0 5169 440 0 440 440 0 8 0
anonpl 16 279575 0 267826 74 24 50 64 0 125 0
amapchunkpl 152 14931 0 14818 15 9 6 10 0 158 0
amappl16 192 16477 0 15824 57 24 33 45 0 8 0
amappl15 184 8 0 8 1 1 0 1 0 8 0
amappl14 176 713 0 704 1 0 1 1 0 8 0
amappl13 168 6 0 6 1 1 0 1 0 8 0
amappl12 160 5 0 4 1 0 1 1 0 8 0
amappl11 152 63 0 48 1 0 1 1 0 8 0
amappl10 144 930 0 923 1 0 1 1 0 8 0
amappl9 136 1943 0 1938 1 0 1 1 0 8 0
amappl8 128 1521 0 1492 2 0 2 2 0 8 0
amappl7 120 890 0 886 1 0 1 1 0 8 0
amappl6 112 59 0 50 1 0 1 1 0 8 0
amappl5 104 155 0 141 1 0 1 1 0 8 0
amappl4 96 3345 0 3312 2 1 1 2 0 8 0
amappl3 88 877 0 866 1 0 1 1 0 8 0
amappl2 80 24226 0 24146 3 1 2 3 0 8 0
amappl1 72 71259 0 70798 26 16 10 20 0 8 0
amappl 80 8665 0 8624 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
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 88 0 13 2 0 2 2 0 8 0
uaddrrnd 24 3078 0 3061 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 3078 0 3061 1 0 1 1 0 8 0
vmmpekpl 168 21960 0 21929 2 0 2 2 0 8 0
vmmpepl 168 369671 0 367766 156 72 84 101 0 357 1
vmsppl 368 3077 0 3061 2 0 2 2 0 8 0
pdppl 4096 6163 0 6122 7 1 6 6 0 8 0
pvpl 32 787515 0 772475 225 99 126 160 0 265 0
pmappl 232 3077 0 3061 2 1 1 2 0 8 0
extentpl 40 41 0 26 1 0 1 1 0 8 0
phpool 112 627 0 15 18 0 18 18 0 8 0