witness: shared lock of (rwlock) pmaddr while exclausively locked

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syzbot

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Jan 4, 2026, 6:10:24 AM (yesterday) Jan 4
to syzkaller-o...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: f9943f26ca81 Use an iterator in uvmpd_scan_active() to pre..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=16d1169a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7058272de1526588
dashboard link: https://syzkaller.appspot.com/bug?extid=4841f908824398df5257

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d6622753111d/disk-f9943f26.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/66335b49a51a/bsd-f9943f26.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a84aac66fddb/kernel-f9943f26.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4841f9...@syzkaller.appspotmail.com

witness: shared lock of (rwlock) pmaddr while exclausively locked
nic: excl->share
Stopped at db_enter+0x25: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
498743 84884 0 0 0 0 syz-executor
*510078 67246 0 0x14000 0x200 1 softclockmp
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833b4a35) at panic+0x1e5 sys/kern/subr_prf.c:198
witness_checkorder(ffff800001595078,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854
rw_do_enter_read(ffff800001595060,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355
in6_hasmulti(fffffd807eb5d9f0,ffff800001595000) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline]
in6_hasmulti(fffffd807eb5d9f0,ffff800001595000) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150
ip6_output(fffffd807eb5d900,ffffffff839eee58,0,0,ffff80002a1fdfa0,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507
mld6_sendpkt(ffff8000015ab480,83,0) at mld6_sendpkt+0x385 sys/netinet6/mld6.c:499
mld6_fasttimo() at mld6_fasttimo+0x16d mld6_checktimer sys/netinet6/mld6.c:395 [inline]
mld6_fasttimo() at mld6_fasttimo+0x16d sys/netinet6/mld6.c:369
pffasttimo(ffffffff83a15020) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1
timeout_run(ffffffff83835dd8,ffffffff83a15020) at timeout_run+0x159 sys/kern/kern_timeout.c:698
softclock_thread_run(ffffffff83835dd8) at softclock_thread_run+0xe7 sys/kern/kern_timeout.c:842
softclock_thread_mp(ffff8000fffff228) at softclock_thread_mp+0x86
end trace frame: 0x0, count: 3
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
*cpu1: excl->share
ddb{1}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833b4a35) at panic+0x1e5 sys/kern/subr_prf.c:198
witness_checkorder(ffff800001595078,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854
rw_do_enter_read(ffff800001595060,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355
in6_hasmulti(fffffd807eb5d9f0,ffff800001595000) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline]
in6_hasmulti(fffffd807eb5d9f0,ffff800001595000) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150
ip6_output(fffffd807eb5d900,ffffffff839eee58,0,0,ffff80002a1fdfa0,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507
mld6_sendpkt(ffff8000015ab480,83,0) at mld6_sendpkt+0x385 sys/netinet6/mld6.c:499
mld6_fasttimo() at mld6_fasttimo+0x16d mld6_checktimer sys/netinet6/mld6.c:395 [inline]
mld6_fasttimo() at mld6_fasttimo+0x16d sys/netinet6/mld6.c:369
pffasttimo(ffffffff83a15020) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1
timeout_run(ffffffff83835dd8,ffffffff83a15020) at timeout_run+0x159 sys/kern/kern_timeout.c:698
softclock_thread_run(ffffffff83835dd8) at softclock_thread_run+0xe7 sys/kern/kern_timeout.c:842
softclock_thread_mp(ffff8000fffff228) at softclock_thread_mp+0x86
end trace frame: 0x0, count: -12
ddb{1}> show registers
rdi 0
rsi 0x1
rbp 0xffff80002a1fdbf0
rbx 0xffff8000299dee07
rdx 0
rcx 0xffff8000fffff228
rax 0xffff8000299ddff0
r8 0x101010101010101
r9 0x8080808080808080
r10 0xd1d8d1b3e08f70e7
r11 0x6bfd9d62cacda47d
r12 0xffff8000299dec08
r13 0
r14 0
r15 0x1
rip 0xffffffff810e0165 db_enter+0x25
cs 0x8
rflags 0x246
rsp 0xffff80002a1fdbe0
ss 0
db_enter+0x25: addq $0x8,%rsp
ddb{1}> show proc
PROC (softclockmp) tid=510078 pid=67246 tcnt=1 stat=onproc
flags process=14000<NOZOMBIE,SYSTEM> proc=200<SYSTEM>
runpri=0, usrpri=50, slppri=0, nice=20
wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
forw=0xffffffffffffffff, list=0xffff8000fffff4c0,0xffff8000ffffed08
process=0xffff8000ffff89a0 user=0xffff80002a1f9000, vmspace=0xffffffff83a0c438
estcpu=0, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0
ddb{1}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
42334 388760 76346 0 2 0 syz-executor
84884 498743 14725 0 7 0 syz-executor
84884 69698 14725 0 2 0x4000000 syz-executor
44686 312679 12537 0 2 0 syz-executor
15805 134114 58213 0 2 0 syz-executor
15805 9535 58213 0 2 0x4000000 syz-executor
66897 225294 23679 0 2 0 syz-executor
66897 443916 23679 0 3 0x4000080 fsleep syz-executor
45856 500838 33691 0 2 0 syz-executor
45856 372287 33691 0 3 0x4000080 fsleep syz-executor
43928 230644 32118 0 2 0x82000 syz-executor
43928 6457 32118 0 4 0x4082000 syz-executor
43928 84538 32118 0 3 0x4002000 suspend syz-executor
28316 31753 50765 0 3 0x80 nanoslp syz-executor
28316 202021 50765 0 3 0x4000080 semwait syz-executor
28316 95966 50765 0 3 0x4000080 fsleep syz-executor
94780 460979 0 0 3 0x14200 acct acct
58213 123868 76121 0 3 0x82 nanoslp syz-executor
12537 384766 76121 0 2 0x3 syz-executor
32118 321908 76121 0 3 0x82 nanoslp syz-executor
14725 498991 76121 0 2 0x2 syz-executor
23679 101637 76121 0 3 0x82 nanoslp syz-executor
33691 521832 76121 0 3 0x82 nanoslp syz-executor
50765 444227 76121 0 2 0x3 syz-executor
76346 202775 76121 0 2 0xc82 syz-executor
76121 496755 20682 0 3 0x82 kqread syz-executor
20682 433223 76933 0 3 0x10008a sigsusp ksh
76933 244608 51579 0 3 0x98 kqread sshd-session
51579 228833 42740 0 3 0x92 kqread sshd-session
70535 430885 1 0 3 0x100083 ttyin getty
42740 171318 1 0 3 0x88 kqread sshd
31922 295433 33553 74 3 0x1100092 bpf pflogd
33553 433094 1 0 3 0x80 sbwait pflogd
13166 41681 643 73 3 0x1100090 kqread syslogd
643 101812 1 0 3 0x100082 sbwait syslogd
94882 317008 1 0 3 0x100080 kqread resolvd
31380 348102 53275 77 3 0x100092 kqread dhcpleased
83874 110874 53275 77 3 0x100092 kqread dhcpleased
53275 278011 1 0 3 0x80 kqread dhcpleased
48983 228069 0 0 3 0x14200 bored smr
66813 349418 0 0 2 0x14200 zerothread
57031 309425 0 0 3 0x14200 aiodoned aiodoned
24481 131432 0 0 3 0x14200 syncer update
11593 264567 0 0 3 0x14200 cleaner cleaner
28355 298970 0 0 3 0x14200 reaper reaper
98934 22645 0 0 3 0x14200 pgdaemon pagedaemon
65882 304679 0 0 3 0x14200 bored viomb
18721 475335 0 0 3 0x40014200 acpi0 acpi0
25709 79440 0 0 3 0x40014200 idle1
4102 227252 0 0 3 0x14200 bored softnet1
37869 265328 0 0 3 0x14200 bored softnet0
97031 119988 0 0 3 0x14200 bored systqmp
79101 108209 0 0 3 0x14200 bored systq
*67246 510078 0 0 7 0x14200 softclockmp
84726 308673 0 0 3 0x40014200 tmoslp softclock
53577 227539 0 0 3 0x40014200 idle0
1 105558 0 0 3 0x82 wait init
0 0 -1 0 3 0x10200 scheduler swapper
ddb{1}> show all locks
Process 84884 (syz-executor) thread 0xffff8000fffea7e8 (69698)
exclusive rwlock vmmaplk r = 0 (0xfffffd806c911120)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_read+0x3e8 sys/kern/kern_rwlock.c:413
#2 uvmfault_lookup+0x122 sys/uvm/uvm_fault.c:1880
#3 uvm_fault_check+0x4f sys/uvm/uvm_fault.c:693
#4 uvm_fault+0x106 sys/uvm/uvm_fault.c:627
#5 upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192
#6 usertrap+0x42f sys/arch/amd64/amd64/trap.c:632
#7 recall_trap+0x8
Process 44686 (syz-executor) thread 0xffff8000fffebca8 (312679)
exclusive rwlock vmmaplk r = 0 (0xfffffd806c911e78)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2 vm_map_lock_ln+0x12e sys/uvm/uvm_map.c:5165
#3 uvm_map_protect+0xe0 sys/uvm/uvm_map.c:3069
#4 sys_mprotect+0x351 sys/uvm/uvm_mmap.c:590
#5 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#5 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775
#6 Xsyscall+0x128
Process 67246 (softclockmp) thread 0xffff8000fffff228 (510078)
exclusive rwlock maddr r = 0 (0xffff800001595078)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2 mld6_fasttimo+0x8c mld6_checktimer sys/netinet6/mld6.c:-1 [inline]
#2 mld6_fasttimo+0x8c sys/netinet6/mld6.c:369
#3 pffasttimo+0x184 sys/kern/uipc_domain.c:-1
#4 timeout_run+0x159 sys/kern/kern_timeout.c:698
#5 softclock_thread_run+0xe7 sys/kern/kern_timeout.c:842
#6 softclock_thread_mp+0x86
#7 proc_trampoline+0x10
shared rwlock netlock r = 0 (0xffffffff83891cc0)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_read+0x3e8 sys/kern/kern_rwlock.c:413
#2 mld6_fasttimo+0x5f sys/netinet6/mld6.c:-1
#3 pffasttimo+0x184 sys/kern/uipc_domain.c:-1
#4 timeout_run+0x159 sys/kern/kern_timeout.c:698
#5 softclock_thread_run+0xe7 sys/kern/kern_timeout.c:842
#6 softclock_thread_mp+0x86
#7 proc_trampoline+0x10
shared rwlock timeout r = 0 (0xffffffff83835d78)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 timeout_run+0x131 sys/kern/kern_timeout.c:694
#2 softclock_thread_run+0xe7 sys/kern/kern_timeout.c:842
#3 softclock_thread_mp+0x86
#4 proc_trampoline+0x10
ddb{1}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 11059 12088K 12542K 166960K 12388 0
pcb 18 12K 12K 166960K 40 0
rtable 240 8K 8K 166960K 410 0
pf 34 17K 18K 166960K 62 0
ifaddr 43 7K 8K 166960K 55 0
ifgroup 55 2K 2K 166960K 72 0
sysctl 4 1K 9K 166960K 10 0
counters 70 37K 37K 166960K 86 0
ioctlops 0 0K 4K 166960K 1506 0
iov 0 0K 12K 166960K 10 0
mount 1 1K 1K 166960K 1 0
log 0 0K 0K 166960K 4 0
vnodes 1410 89K 89K 166960K 1570 0
UFS quota 1 32K 32K 166960K 1 0
UFS mount 5 36K 36K 166960K 5 0
shm 2 1K 9K 166960K 6 0
VM map 2 1K 1K 166960K 2 0
sem 6 0K 0K 166960K 7 0
dirhash 12 2K 2K 166960K 15 0
ACPI 1692 195K 286K 166960K 12470 0
file desc 18 65K 85K 166960K 262 0
sigio 0 0K 0K 166960K 8 0
proc 72 115K 164K 166960K 543 0
subproc 72 4K 4K 166960K 72 0
NFS srvsock 1 0K 0K 166960K 1 0
NFS daemon 1 16K 16K 166960K 1 0
ip_moptions 0 0K 0K 166960K 15 0
in_multi 102 7K 7K 166960K 110 0
ether_multi 2 0K 0K 166960K 2 0
mrt 2 0K 0K 166960K 2 0
ISOFS mount 1 32K 32K 166960K 1 0
MSDOSFS mount 1 16K 16K 166960K 1 0
ttys 67 307K 307K 166960K 67 0
exec 0 0K 1K 166960K 381 0
fusefs mount 1 32K 32K 166960K 1 0
pfkey data 0 0K 0K 166960K 1 0
tdb 3 0K 0K 166960K 3 0
VM swap 8 62K 64K 166960K 10 0
UVM amap 237 168K 175K 166960K 4209 0
UVM aobj 9 2K 4K 166960K 11 0
pinsyscall 43 86K 102K 166960K 1386 0
memdesc 1 4K 4K 166960K 1 0
crypto data 1 1K 1K 166960K 1 0
ip6_options 0 0K 0K 166960K 5 0
NDP 12 0K 2K 166960K 32 0
temp 41 8671K 8735K 166960K 12223 0
kqueue 14 20K 28K 166960K 49 0
SYN cache 2 16K 16K 166960K 2 0
ddb{1}> 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 41 0 37 1 0 1 1 0 8 0
rtentry 176 114 0 7 6 0 6 6 0 8 0
unpcb 144 158 0 141 4 3 1 4 0 8 0
syncache 336 3 0 3 1 1 0 1 0 8 0
tcpcb 736 34 0 30 1 0 1 1 0 8 0
arp 136 18 0 2 1 0 1 1 0 8 0
inpcb 328 145 0 137 2 0 2 2 0 8 0
nd6 152 25 0 0 1 0 1 1 0 8 0
pkpcb 40 2 0 2 1 1 0 1 0 8 0
kcovpl 48 8 0 0 1 0 1 1 0 8 0
ppxss 1192 5 0 5 1 1 0 1 0 8 0
pppxif 1576 2 0 2 1 1 0 1 0 8 0
pffrag 232 2 0 0 1 0 1 1 0 482 0
pffrnode 88 2 0 0 1 0 1 1 0 8 0
pffrent 40 2 0 0 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
pfstitem 24 23 0 0 1 0 1 1 0 8 0
pfstkey 128 23 0 0 1 0 1 1 0 8 0
pfstate 448 23 0 0 3 0 3 3 0 8 0
pfrule 1344 22 0 17 2 1 1 2 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 467 0 16 29 0 29 29 0 8 0
art_table 40 468 0 16 5 0 5 5 0 8 0
art_node 32 114 0 17 1 0 1 1 0 8 0
sysvmsgpl 40 6 0 3 1 0 1 1 0 8 0
semapl 112 4 0 1 1 0 1 1 0 8 0
shmpl 112 7 0 1 1 0 1 1 0 8 0
dirhash 1024 19 0 2 3 0 3 3 0 8 0
dino2pl 256 1822 0 308 96 0 96 96 0 8 0
ffsino 296 1822 0 308 118 0 118 118 0 8 0
nchpl 144 2180 0 485 64 0 64 64 0 8 0
rtmask 32 1 0 1 1 1 0 1 0 8 0
vnodes 216 2046 0 0 114 0 114 114 0 8 0
namei 1024 6843 0 6842 2 1 1 2 0 8 0
percpumem 16 58 0 8 1 0 1 1 0 8 0
vmpool 848 1 0 1 1 1 0 1 0 8 0
kstatmem 264 34 0 8 3 1 2 3 0 8 0
scxspl 216 7368 0 7368 10 2 8 8 1 8 8
plimitpl 152 42 0 25 1 0 1 1 0 8 0
sigapl 424 571 0 522 7 1 6 7 0 8 0
knotepl 120 278 0 0 9 0 9 9 0 8 0
kqueuepl 224 142 0 132 3 2 1 3 0 8 0
pipepl 344 127 0 100 3 0 3 3 0 8 0
fdescpl 528 554 0 522 3 0 3 3 0 8 0
filepl 160 2599 0 2385 14 4 10 14 0 8 1
lockfpl 104 123 0 120 1 0 1 1 0 8 0
lockfspl 48 27 0 24 1 0 1 1 0 8 0
sessionpl 144 22 0 13 1 0 1 1 0 8 0
pgrppl 48 35 0 18 1 0 1 1 0 8 0
ucredpl 104 271 0 258 1 0 1 1 0 8 0
zombiepl 144 527 0 527 2 1 1 1 0 8 1
processpl 1232 571 0 522 5 0 5 5 0 8 0
procpl 664 812 0 755 6 0 6 6 0 8 0
sockpl 752 351 0 321 10 6 4 10 0 8 0
mcl64k 65536 2 0 0 1 0 1 1 0 8 0
mcl9k 9216 1 0 0 1 0 1 1 0 8 0
mcl8k 8192 2 0 0 1 0 1 1 0 8 0
mcl4k 4096 115 0 0 15 0 15 15 0 8 0
mcl2k 2048 28 0 0 4 0 4 4 0 8 0
mtagpl 96 10 0 0 1 0 1 1 0 8 0
mbufpl 256 153 0 0 10 0 10 10 0 8 0
bufpl 280 2664 0 130 181 0 181 181 0 8 0
anonpl 32 7665 0 0 62 0 62 62 0 246 0
amapchunkpl 152 12406 0 11936 22 1 21 22 0 158 2
amappl16 200 2831 0 2804 18 15 3 15 0 8 0
amappl15 192 6 0 6 1 1 0 1 0 8 0
amappl14 184 4 0 4 1 1 0 1 0 8 0
amappl13 176 421 0 420 1 0 1 1 0 8 0
amappl12 168 919 0 877 2 0 2 2 0 8 0
amappl11 160 10 0 9 1 0 1 1 0 8 0
amappl10 152 48 0 34 1 0 1 1 0 8 0
amappl9 144 248 0 248 1 1 0 1 0 8 0
amappl8 136 31 0 29 1 0 1 1 0 8 0
amappl7 128 80 0 79 1 0 1 1 0 8 0
amappl6 120 278 0 265 1 0 1 1 0 8 0
amappl5 112 82 0 71 1 0 1 1 0 8 0
amappl4 104 418 0 389 1 0 1 1 0 8 0
amappl3 96 2057 0 1968 4 1 3 3 0 8 0
amappl2 88 663 0 587 2 0 2 2 0 8 0
amappl1 80 9547 0 8945 14 1 13 14 0 8 0
amappl 88 3469 0 3311 5 0 5 5 0 92 0
uvmvnodes 80 103 0 0 3 0 3 3 0 8 0
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 128 253 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 18 0 17 1 0 1 1 0 8 0
aobjpl 72 10 0 2 1 0 1 1 0 8 0
uaddrrnd 24 554 0 522 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 554 0 522 1 0 1 1 0 8 0
vmmpekpl 168 6369 0 6340 2 0 2 2 0 8 0
vmmpepl 168 43471 0 41519 96 6 90 96 0 357 4
vmsppl 488 553 0 522 5 1 4 5 0 8 0
rwobjpl 80 15706 0 14675 27 2 25 27 0 8 0
pdppl 4096 1118 0 1046 94 22 72 82 0 8 0
pvpl 32 14267 0 0 117 1 116 116 0 265 0
pmappl 256 554 0 523 3 0 3 3 0 8 0
extentpl 40 45 0 27 1 0 1 1 0 8 0
phpool 112 267 0 26 8 0 8 8 0 8 0
ddb{1}> machine ddbcpu 0
Stopped at x86_ipi_db+0x27: addq $0x8,%rsp
x86_ipi_db(ffffffff837e3ff0) 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
end of kernel
end trace frame: 0x7b1a78880710, count: 12
ddb{0}> trace
x86_ipi_db(ffffffff837e3ff0) 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
end of kernel
end trace frame: 0x7b1a78880710, count: -3
ddb{0}> machine ddbcpu 1
Stopped at db_enter+0x25: addq $0x8,%rsp
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833b4a35) at panic+0x1e5 sys/kern/subr_prf.c:198
witness_checkorder(ffff800001595078,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854
rw_do_enter_read(ffff800001595060,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355
in6_hasmulti(fffffd807eb5d9f0,ffff800001595000) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline]
in6_hasmulti(fffffd807eb5d9f0,ffff800001595000) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150
ip6_output(fffffd807eb5d900,ffffffff839eee58,0,0,ffff80002a1fdfa0,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507
mld6_sendpkt(ffff8000015ab480,83,0) at mld6_sendpkt+0x385 sys/netinet6/mld6.c:499
mld6_fasttimo() at mld6_fasttimo+0x16d mld6_checktimer sys/netinet6/mld6.c:395 [inline]
mld6_fasttimo() at mld6_fasttimo+0x16d sys/netinet6/mld6.c:369
pffasttimo(ffffffff83a15020) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1
timeout_run(ffffffff83835dd8,ffffffff83a15020) at timeout_run+0x159 sys/kern/kern_timeout.c:698
softclock_thread_run(ffffffff83835dd8) at softclock_thread_run+0xe7 sys/kern/kern_timeout.c:842
softclock_thread_mp(ffff8000fffff228) at softclock_thread_mp+0x86
end trace frame: 0x0, count: 3
ddb{1}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff833b4a35) at panic+0x1e5 sys/kern/subr_prf.c:198
witness_checkorder(ffff800001595078,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854
rw_do_enter_read(ffff800001595060,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355
in6_hasmulti(fffffd807eb5d9f0,ffff800001595000) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline]
in6_hasmulti(fffffd807eb5d9f0,ffff800001595000) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150
ip6_output(fffffd807eb5d900,ffffffff839eee58,0,0,ffff80002a1fdfa0,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507
mld6_sendpkt(ffff8000015ab480,83,0) at mld6_sendpkt+0x385 sys/netinet6/mld6.c:499
mld6_fasttimo() at mld6_fasttimo+0x16d mld6_checktimer sys/netinet6/mld6.c:395 [inline]
mld6_fasttimo() at mld6_fasttimo+0x16d sys/netinet6/mld6.c:369
pffasttimo(ffffffff83a15020) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1
timeout_run(ffffffff83835dd8,ffffffff83a15020) at timeout_run+0x159 sys/kern/kern_timeout.c:698
softclock_thread_run(ffffffff83835dd8) at softclock_thread_run+0xe7 sys/kern/kern_timeout.c:842
softclock_thread_mp(ffff8000fffff228) at softclock_thread_mp+0x86
end trace frame: 0x0, count: -12


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