panic: kernel diagnostic assertion "refs > 1" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 920
Stopped at db_enter+0x25: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
* 43504 69251 0 0 0x4000000 0 syz-executor
78522 86413 0 0x2 0 1 syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833aa43c) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff833e8e72,ffffffff833f5f7c,398,ffffffff833b1271) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_take(ffff80000148d008) at refcnt_take+0x109 sys/kern/kern_synch.c:921
if_getgroupmembers(ffff800037bf0da0) at if_getgroupmembers+0x11d sys/net/if.c:3185
sys_ioctl(ffff8000397f3a28,ffff800037bf0f80,ffff800037bf0ed0) at sys_ioctl+0x674 sys/kern/sys_generic.c:-1
syscall(ffff800037bf0f80) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800037bf0f80) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x90990b43bc0, count: 7
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
*cpu0: kernel diagnostic assertion "refs > 1" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 920
ddb{0}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833aa43c) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff833e8e72,ffffffff833f5f7c,398,ffffffff833b1271) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_take(ffff80000148d008) at refcnt_take+0x109 sys/kern/kern_synch.c:921
if_getgroupmembers(ffff800037bf0da0) at if_getgroupmembers+0x11d sys/net/if.c:3185
sys_ioctl(ffff8000397f3a28,ffff800037bf0f80,ffff800037bf0ed0) at sys_ioctl+0x674 sys/kern/sys_generic.c:-1
syscall(ffff800037bf0f80) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800037bf0f80) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x90990b43bc0, count: -8
ddb{0}> show registers
rdi 0
rsi 0x1
rbp 0xffff800037bf0c00
rbx 0xffffffff83807e07 cpu_info_full_primary+0x2e07
rdx 0xffff800001480680
rcx 0xffff8000397f3a28
rax 0xffffffff83806ff0 cpu_info_full_primary+0x1ff0
r8 0x101010101010101
r9 0x8080808080808080
r10 0x7887142a4c9060b9
r11 0x7a8a95cbf136b197
r12 0xffffffff83807c08 cpu_info_full_primary+0x2c08
r13 0
r14 0
r15 0x1
rip 0xffffffff83306035 db_enter+0x25
cs 0x8
rflags 0x246
rsp 0xffff800037bf0bf0
ss 0x10
db_enter+0x25: addq $0x8,%rsp
ddb{0}> show proc
PROC (syz-executor) tid=43504 pid=69251 tcnt=2 stat=onproc
flags process=0 proc=4000000<THREAD>
runpri=32, usrpri=50, slppri=32, nice=20
wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
forw=0xffffffffffffffff, list=0xffff8000397f22d0,0xffff8000397f2aa8
process=0xffff80002ac5d840 user=0xffff800037bec000, vmspace=0xfffffd806ca905d8
estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0
ddb{0}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
35876 127417 20486 0 2 0 syz-executor
35876 333154 20486 0 2 0x4000000 syz-executor
25846 352935 27601 0 2 0 syz-executor
25846 335145 27601 0 3 0x4000080 fsleep syz-executor
25846 452578 27601 0 2 0x4000000 syz-executor
69251 216627 60634 0 2 0 syz-executor
*69251 43504 60634 0 7 0x4000000 syz-executor
71123 172007 5162 0 2 0 syz-executor
71123 244056 5162 0 3 0x4000000 lockflk syz-executor
71123 450973 5162 0 2 0x4000000 syz-executor
73043 343085 29927 0 2 0 syz-executor
73043 427900 29927 0 3 0x4000080 fsleep syz-executor
79559 501524 0 0 3 0x14200 acct acct
32277 503882 0 0 3 0x14280 nfsidl nfsio
25113 279115 0 0 3 0x14280 nfsidl nfsio
45960 378691 0 0 3 0x14280 nfsidl nfsio
64458 32704 0 0 3 0x14280 nfsidl nfsio
65778 305837 0 0 3 0x14280 nfsidl nfsio
25327 98842 0 0 3 0x14280 nfsidl nfsio
22322 507109 0 0 3 0x14280 nfsidl nfsio
32083 268261 0 0 3 0x14280 nfsidl nfsio
60509 206254 0 0 3 0x14280 nfsidl nfsio
27501 424010 0 0 3 0x14280 nfsidl nfsio
15502 90479 0 0 3 0x14280 nfsidl nfsio
18880 24691 0 0 3 0x14280 nfsidl nfsio
36677 51129 0 0 3 0x14280 nfsidl nfsio
90720 505778 0 0 3 0x14280 nfsidl nfsio
14392 259286 0 0 3 0x14280 nfsidl nfsio
18702 196247 0 0 3 0x14280 nfsidl nfsio
38019 351353 0 0 3 0x14280 nfsidl nfsio
84568 384959 0 0 3 0x14280 nfsidl nfsio
21378 5652 0 0 3 0x14280 nfsidl nfsio
76537 410270 0 0 3 0x14280 nfsidl nfsio
67402 74412 55744 0 3 0x82 wait syz-executor
29927 260703 55744 0 2 0xc82 syz-executor
27601 249317 55744 0 3 0x82 nanoslp syz-executor
60634 69232 55744 0 2 0x3 syz-executor
20486 496376 55744 0 2 0xc82 syz-executor
5162 96073 55744 0 3 0x82 nanoslp syz-executor
6162 87038 55744 0 3 0x82 nanoslp syz-executor
86413 78522 55744 0 7 0x2 syz-executor
55744 119295 40581 0 2 0x3 syz-executor
40581 113812 32823 0 3 0x10008a sigsusp ksh
32823 116886 60869 0 3 0x98 kqread sshd-session
60869 366491 77042 0 3 0x92 kqread sshd-session
60975 279858 1 0 3 0x100083 ttyopn getty
77042 67026 1 0 3 0x88 kqread sshd
67196 278279 31704 74 3 0x1100092 bpf pflogd
31704 292151 1 0 3 0x80 sbwait pflogd
63114 523124 71602 73 3 0x1100090 kqread syslogd
71602 84807 1 0 3 0x100082 sbwait syslogd
47578 123918 1 0 3 0x100080 kqread resolvd
25901 272782 81195 77 3 0x100092 kqread dhcpleased
83769 368418 81195 77 3 0x100092 kqread dhcpleased
81195 441409 1 0 3 0x80 kqread dhcpleased
52761 349895 0 0 3 0x14200 bored smr
63777 360970 0 0 2 0x14200 zerothread
43055 28943 0 0 3 0x14200 aiodoned aiodoned
22062 40242 0 0 3 0x14200 syncer update
97918 116204 0 0 3 0x14200 cleaner cleaner
18637 468571 0 0 3 0x14200 reaper reaper
79115 47444 0 0 3 0x14200 pgdaemon pagedaemon
18613 225608 0 0 3 0x14200 bored viomb
50527 444696 0 0 3 0x40014200 acpi0 acpi0
20286 62430 0 0 3 0x40014200 idle1
70459 373705 0 0 3 0x14200 bored softnet1
97401 427582 0 0 3 0x14200 bored softnet0
29545 499147 0 0 3 0x14200 bored systqmp
95526 159720 0 0 3 0x14200 bored systq
27721 403654 0 0 3 0x14200 tmoslp softclockmp
80525 500793 0 0 3 0x40014200 tmoslp softclock
44445 194566 0 0 3 0x40014200 idle0
1 339741 0 0 3 0x82 wait init
0 0 -1 0 3 0x10010200 scheduler swapper
ddb{0}> show all locks
Process 35876 (syz-executor) thread 0xffff8000397f8d18 (333154)
Process 25846 (syz-executor) thread 0xffff8000397f87e8 (452578)
Process 69251 (syz-executor) thread 0xffff8000397f3a28 (43504)
Process 71123 (syz-executor) thread 0xffff8000397f2038 (244056)
Process 71123 (syz-executor) thread 0xffff8000397f3790 (450973)
Process 86413 (syz-executor) thread 0xffff8000ffffc538 (78522)
ddb{0}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 10214 11095K 11395K 166960K 12303 0
pcb 18 13K 14K 166960K 160 0
rtable 235 10K 11K 166960K 465 0
pf 37 18K 83K 166960K 119 0
ifaddr 39 6K 7K 166960K 81 0
ifgroup 58 2K 3K 166960K 126 0
sysctl 4 1K 9K 166960K 17 0
counters 70 37K 38K 166960K 154 0
ioctlops 0 0K 4K 166960K 1652 0
iov 0 0K 12K 166960K 76 0
mount 1 1K 1K 166960K 1 0
log 0 0K 0K 166960K 4 0
vnodes 1394 88K 89K 166960K 1961 0
UFS quota 1 32K 32K 166960K 1 0
UFS mount 5 36K 36K 166960K 5 0
shm 2 2K 9K 166960K 13 0
VM map 2 1K 1K 166960K 2 0
sem 12 0K 0K 166960K 33 0
dirhash 12 2K 2K 166960K 21 0
ACPI 1692 195K 286K 166960K 12470 0
file desc 17 61K 89K 166960K 795 0
sigio 0 0K 0K 166960K 13 0
proc 76 131K 164K 166960K 628 0
subproc 72 4K 4K 166960K 81 0
NFS srvsock 1 0K 0K 166960K 1 0
NFS daemon 1 16K 16K 166960K 1 0
ip_moptions 0 0K 0K 166960K 158 0
in_multi 81 5K 7K 166960K 145 0
ether_multi 1 0K 0K 166960K 10 0
mrt 1 0K 0K 166960K 5 0
ISOFS mount 1 32K 32K 166960K 1 0
MSDOSFS mount 1 16K 16K 166960K 1 0
ttys 103 466K 466K 166960K 103 0
exec 0 0K 1K 166960K 549 0
fusefs mount 1 32K 32K 166960K 1 0
tdb 3 0K 0K 166960K 3 0
VM swap 8 62K 64K 166960K 10 0
UVM amap 245 167K 181K 166960K 9093 0
UVM aobj 14 2K 4K 166960K 18 0
pinsyscall 42 84K 98K 166960K 1948 0
memdesc 1 4K 4K 166960K 1 0
crypto data 1 1K 1K 166960K 1 0
ip6_options 0 0K 0K 166960K 58 0
NDP 12 0K 1K 166960K 56 0
temp 70 8678K 8751K 166960K 47604 0
kqueue 13 20K 28K 166960K 131 0
SYN cache 2 16K 16K 166960K 2 0
ddb{0}> show all pools
Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
plcache 128 26 0 0 1 0 1 1 0 8 0
rtpcb 120 80 0 77 1 0 1 1 0 8 0
rtentry 176 138 0 41 6 1 5 6 0 8 0
unpcb 144 493 0 475 6 3 3 3 0 8 2
syncache 336 3 0 3 1 1 0 1 0 8 0
tcpcb 736 270 0 266 10 8 2 7 0 8 1
arp 136 22 0 7 1 0 1 1 0 8 0
ipq 40 1 0 1 1 1 0 1 0 8 0
ipqe 40 3 0 3 1 1 0 1 0 8 0
inpcb 328 801 0 792 18 16 2 12 0 8 1
nd6 152 31 0 10 1 0 1 1 0 8 0
pkpcb 40 33 0 33 1 1 0 1 0 8 0
kcovpl 48 9 0 1 1 0 1 1 0 8 0
ppxss 1192 36 0 36 1 0 1 1 0 8 1
pppxif 1504 2 0 2 1 1 0 1 0 8 0
pfstscr 40 2 0 0 1 0 1 1 0 8 0
pffrag 232 10 0 3 1 0 1 1 0 482 0
pffrnode 88 10 0 3 1 0 1 1 0 8 0
pffrent 40 106 0 99 1 0 1 1 0 8 0
pfosfp 40 1428 0 1005 5 0 5 5 0 8 0
pfosfpen 112 1428 0 714 21 0 21 21 0 8 0
pfrktable 1344 1 0 1 1 0 1 1 0 8 1
pfanchor 1288 1 0 1 1 0 1 1 0 8 1
pftag 88 1 0 1 1 0 1 1 0 8 1
pfstitem 24 56 0 16 1 0 1 1 0 8 0
pfstkey 128 56 0 17 2 0 2 2 0 8 0
pfstate 448 55 0 16 5 0 5 5 0 8 0
pfrule 1344 22 0 17 2 1 1 2 0 8 0
art_heap8 4096 3 0 0 3 0 3 3 0 8 0
art_heap4 256 533 0 141 31 3 28 29 0 8 1
art_table 40 536 0 141 5 0 5 5 0 8 0
art_node 32 137 0 49 1 0 1 1 0 8 0
sysvmsgpl 40 8 0 5 1 0 1 1 0 8 0
semupl 112 1 0 1 1 1 0 1 0 8 0
semapl 112 28 0 18 1 0 1 1 0 8 0
shmpl 112 14 0 3 1 0 1 1 0 8 0
dirhash 1024 23 0 6 3 0 3 3 0 8 0
dino2pl 256 2796 0 1295 95 0 95 95 0 8 0
ffsino 296 2796 0 1295 117 0 117 117 0 8 0
nchpl 144 3914 0 2215 64 0 64 64 0 8 0
rtmask 32 7 0 7 2 2 0 1 0 8 0
vnodes 216 3229 0 0 180 0 180 180 0 8 0
namei 1024 12864 0 12864 3 2 1 2 0 8 1
percpumem 16 92 0 42 1 0 1 1 0 8 0
vmpool 840 1 0 1 1 1 0 1 0 8 0
kstatmem 264 78 0 50 3 0 3 3 0 8 1
scsiplug 72 4 0 4 2 1 1 1 0 8 1
scxspl 216 20880 0 20880 10 2 8 8 1 8 8
plimitpl 152 227 0 210 1 0 1 1 0 8 0
sigapl 424 1124 0 1056 9 1 8 8 0 8 0
knotepl 120 558 0 0 17 0 17 17 0 8 0
kqueuepl 224 315 0 305 7 2 5 5 0 8 4
pipepl 344 218 0 191 3 0 3 3 0 8 0
fdescpl 528 1086 0 1055 3 0 3 3 0 8 0
filepl 160 6082 0 5864 21 7 14 18 0 8 2
lockfpl 104 205 0 201 1 0 1 1 0 8 0
lockfspl 48 88 0 84 1 0 1 1 0 8 0
sessionpl 144 23 0 14 1 0 1 1 0 8 0
pgrppl 48 46 0 29 1 0 1 1 0 8 0
ucredpl 104 747 0 734 1 0 1 1 0 8 0
zombiepl 144 1392 0 1390 1 0 1 1 0 8 0
processpl 1232 1124 0 1056 7 1 6 6 0 8 0
procpl 664 2341 0 2266 8 0 8 8 0 8 0
sosppl 176 2 0 2 1 0 1 1 0 8 1
sockpl 752 1423 0 1393 30 22 8 21 0 8 4
mcl64k 65536 4 0 0 1 0 1 1 0 8 0
mcl8k 8192 2 0 0 1 0 1 1 0 8 0
mcl4k 4096 130 0 0 17 0 17 17 0 8 0
mcl2k 2048 30 0 0 4 0 4 4 0 8 0
mtagpl 96 94 0 0 3 0 3 3 0 8 0
mbufpl 256 1270 0 0 79 0 79 79 0 8 0
bufpl 280 8211 0 2075 439 0 439 439 0 8 0
anonpl 32 10539 0 0 85 0 85 85 0 246 0
amapchunkpl 152 29599 0 29098 37 8 29 30 0 158 7
amappl16 200 3956 0 3917 41 26 15 22 0 8 7
amappl15 192 10 0 10 1 1 0 1 0 8 0
amappl14 184 58 0 58 2 2 0 1 0 8 0
amappl13 176 438 0 437 1 0 1 1 0 8 0
amappl12 168 1477 0 1435 2 0 2 2 0 8 0
amappl11 160 7 0 7 1 1 0 1 0 8 0
amappl10 152 50 0 36 1 0 1 1 0 8 0
amappl9 144 279 0 279 1 1 0 1 0 8 0
amappl8 136 26 0 24 1 0 1 1 0 8 0
amappl7 128 83 0 82 1 0 1 1 0 8 0
amappl6 120 302 0 287 1 0 1 1 0 8 0
amappl5 112 89 0 77 1 0 1 1 0 8 0
amappl4 104 453 0 423 1 0 1 1 0 8 0
amappl3 96 5202 0 5106 4 1 3 3 0 8 0
amappl2 88 1191 0 1115 2 0 2 2 0 8 0
amappl1 80 11808 0 11215 14 1 13 14 0 8 0
amappl 88 8245 0 8077 6 1 5 5 0 92 0
uvmvnodes 80 117 0 0 3 0 3 3 0 8 0
dma65536 65536 1 0 1 1 0 1 1 0 8 1
dma4096 4096 1 0 1 1 1 0 1 0 8 0
dma1024 1024 1 0 0 1 0 1 1 0 8 0
dma256 256 6 0 6 1 1 0 1 0 8 0
dma128 128 254 0 254 2 1 1 1 0 8 1
dma64 64 7 0 7 2 2 0 1 0 8 0
dma32 32 7 0 7 1 1 0 1 0 8 0
dma16 16 18 0 17 1 0 1 1 0 8 0
aobjpl 72 17 0 4 1 0 1 1 0 8 0
uaddrrnd 24 1086 0 1055 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 1086 0 1055 1 0 1 1 0 8 0
vmmpekpl 168 10338 0 10292 3 0 3 3 0 8 0
vmmpepl 168 75931 0 73989 119 15 104 104 0 357 11
vmsppl 488 1085 0 1055 5 0 5 5 0 8 0
rwobjpl 80 22732 0 21658 34 4 30 30 0 8 2
pdppl 4096 2182 0 2112 106 34 72 84 0 8 2
pvpl 32 18695 0 0 152 1 151 151 0 265 0
pmappl 256 1086 0 1056 3 0 3 3 0 8 0
extentpl 40 45 0 27 1 0 1 1 0 8 0
phpool 112 366 0 50 10 0 10 10 0 8 0
ddb{0}> machine ddbcpu 0
Invalid cpu 0
ddb{0}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833aa43c) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff833e8e72,ffffffff833f5f7c,398,ffffffff833b1271) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_take(ffff80000148d008) at refcnt_take+0x109 sys/kern/kern_synch.c:921
if_getgroupmembers(ffff800037bf0da0) at if_getgroupmembers+0x11d sys/net/if.c:3185
sys_ioctl(ffff8000397f3a28,ffff800037bf0f80,ffff800037bf0ed0) at sys_ioctl+0x674 sys/kern/sys_generic.c:-1
syscall(ffff800037bf0f80) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800037bf0f80) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x90990b43bc0, count: -8
ddb{0}> machine ddbcpu 1
Stopped at x86_ipi_db+0x27: addq $0x8,%rsp
x86_ipi_db(ffff8000299ddff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__mp_lock(ffffffff839a9320) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline]
__mp_lock(ffffffff839a9320) at __mp_lock+0x192 sys/kern/kern_lock.c:165
__mp_acquire_count(ffffffff839a9320,1) at __mp_acquire_count+0x58 sys/kern/kern_lock.c:-1
sleep_finish(ffffffffffffffff,1) at sleep_finish+0x2d8 sys/kern/kern_synch.c:369
biowait(fffffd800b081230) at biowait+0xc6 sys/kern/vfs_bio.c:1242
bwrite(fffffd800b081230) at bwrite+0x2e7 sys/kern/vfs_bio.c:754
ffs_update(fffffd806b71b4e0,1) at ffs_update+0x2fe sys/ufs/ffs/ffs_inode.c:111
ffs_truncate(fffffd806b71b4e0,0,4,fffffd80097fd618) at ffs_truncate+0xc9b sys/ufs/ffs/ffs_inode.c:-1
ufs_rmdir(ffff80002a2e8700) at ufs_rmdir+0x2f1 sys/ufs/ufs/ufs_vnops.c:1265
VOP_RMDIR(fffffd806e2cc6f8,fffffd80653b4998,ffff80002a2e87d8) at VOP_RMDIR+0x192 sys/kern/vfs_vops.c:413
dounlinkat(ffff8000ffffc538,ffffff9c,77c38368f5f0,8) at dounlinkat+0x2e0 sys/kern/vfs_syscalls.c:1901
syscall(ffff80002a2e8950) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a2e8950) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:775
end trace frame: 0xffff80002a2e89d0, count: 0
ddb{1}> trace
x86_ipi_db(ffff8000299ddff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__mp_lock(ffffffff839a9320) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline]
__mp_lock(ffffffff839a9320) at __mp_lock+0x192 sys/kern/kern_lock.c:165
__mp_acquire_count(ffffffff839a9320,1) at __mp_acquire_count+0x58 sys/kern/kern_lock.c:-1
sleep_finish(ffffffffffffffff,1) at sleep_finish+0x2d8 sys/kern/kern_synch.c:369
biowait(fffffd800b081230) at biowait+0xc6 sys/kern/vfs_bio.c:1242
bwrite(fffffd800b081230) at bwrite+0x2e7 sys/kern/vfs_bio.c:754
ffs_update(fffffd806b71b4e0,1) at ffs_update+0x2fe sys/ufs/ffs/ffs_inode.c:111
ffs_truncate(fffffd806b71b4e0,0,4,fffffd80097fd618) at ffs_truncate+0xc9b sys/ufs/ffs/ffs_inode.c:-1
ufs_rmdir(ffff80002a2e8700) at ufs_rmdir+0x2f1 sys/ufs/ufs/ufs_vnops.c:1265
VOP_RMDIR(fffffd806e2cc6f8,fffffd80653b4998,ffff80002a2e87d8) at VOP_RMDIR+0x192 sys/kern/vfs_vops.c:413
dounlinkat(ffff8000ffffc538,ffffff9c,77c38368f5f0,8) at dounlinkat+0x2e0 sys/kern/vfs_syscalls.c:1901
syscall(ffff80002a2e8950) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a2e8950) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:775
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x77c38368f5e0, count: -15