witness: shared lock of (rwlock) maddr while exclusively locked panic: excl->share Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 417758 26809 0 0 0 0 syz-executor * 28393 99333 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(ffff8000015a7878,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854 rw_do_enter_read(ffff8000015a7860,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355 in6_hasmulti(fffffd80692f93f0,ffff8000015a7800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd80692f93f0,ffff8000015a7800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd80692f9300,ffffffff839eee58,0,0,ffff80002a1fece0,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff80000154c100,83,0) 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(ffff8000ffffe298) 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(ffff8000015a7878,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854 rw_do_enter_read(ffff8000015a7860,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355 in6_hasmulti(fffffd80692f93f0,ffff8000015a7800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd80692f93f0,ffff8000015a7800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd80692f9300,ffffffff839eee58,0,0,ffff80002a1fece0,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff80000154c100,83,0) 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(ffff8000ffffe298) at softclock_thread_mp+0x86 end trace frame: 0x0, count: -12 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff80002a1fe930 rbx 0xffff8000299dee07 rdx 0 rcx 0xffff8000ffffe298 rax 0xffff8000299ddff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0x37f77734816f3fb2 r11 0x17ac7962c89c1a77 r12 0xffff8000299dec08 r13 0 r14 0 r15 0x1 rip 0xffffffff810e0165 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a1fe920 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (softclockmp) tid=28393 pid=99333 tcnt=1 stat=onproc flags process=14000 proc=200 runpri=0, usrpri=50, slppri=0, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000ffffe000,0xffff8000ffffe540 process=0xffff8000ffff9340 user=0xffff80002a1f9000, vmspace=0xffffffff83a0c438 estcpu=0, cpticks=1, pctcpu=0.0, user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 26809 417758 26155 0 7 0 syz-executor 26809 332233 26155 0 2 0x4000000 syz-executor 26809 515338 26155 0 2 0x4000000 syz-executor 99734 344686 74121 0 2 0 syz-executor 99734 455407 74121 0 2 0x4000000 syz-executor 40232 141793 6112 0 2 0 syz-executor 40232 416282 6112 0 2 0x4000000 syz-executor 4640 63418 45085 0 2 0xc80 syz-executor 4640 236724 45085 0 3 0x4000080 fsleep syz-executor 4640 419115 45085 0 3 0x4000080 fsleep syz-executor 4640 357622 45085 0 3 0x4000080 fsleep syz-executor 57677 363396 19530 0 2 0xc80 syz-executor 57677 29461 19530 0 3 0x4000080 kqread syz-executor 57677 425630 19530 0 3 0x4000080 fsleep syz-executor 68162 294919 56179 0 2 0xc80 syz-executor 68162 268665 56179 0 3 0x4000080 ttyout syz-executor 68162 342283 56179 0 3 0x4000080 ttyout syz-executor 68162 361107 56179 0 3 0x4000080 ttyin syz-executor 68162 281717 56179 0 3 0x4000080 fsleep syz-executor 74121 443270 44121 0 2 0xc82 syz-executor 26155 462089 44121 0 2 0xc82 syz-executor 56179 10593 44121 0 2 0xc82 syz-executor 23466 88063 44121 0 2 0xc82 syz-executor 45085 306865 44121 0 2 0xc82 syz-executor 19530 466062 44121 0 2 0xc82 syz-executor 6112 344238 44121 0 2 0xc82 syz-executor 40028 46652 44121 0 2 0xc82 syz-executor 44121 291388 66709 0 3 0x82 kqread syz-executor 66709 24822 76616 0 3 0x10008a sigsusp ksh 76616 464869 11978 0 3 0x98 kqread sshd-session 11978 131570 98022 0 3 0x92 kqread sshd-session 29949 43566 1 0 3 0x100083 ttyin getty 98022 90056 1 0 3 0x88 kqread sshd 98160 431651 12681 74 3 0x1100092 bpf pflogd 12681 427683 1 0 3 0x80 sbwait pflogd 42947 175655 69173 73 3 0x1100090 kqread syslogd 69173 446576 1 0 3 0x100082 sbwait syslogd 30110 441775 1 0 3 0x100080 kqread resolvd 44293 79243 27632 77 3 0x100092 kqread dhcpleased 2817 367029 27632 77 3 0x100092 kqread dhcpleased 27632 326207 1 0 3 0x80 kqread dhcpleased 23104 518999 0 0 2 0x40014200 smr 67462 217836 0 0 2 0x14200 zerothread 68146 293219 0 0 3 0x14200 aiodoned aiodoned 66303 444952 0 0 2 0x14e00 update 31416 83687 0 0 3 0x14200 cleaner cleaner 93262 161755 0 0 3 0x14200 reaper reaper 40979 322931 0 0 3 0x14200 pgdaemon pagedaemon 3033 41483 0 0 3 0x14200 bored viomb 89889 248735 0 0 3 0x40014200 acpi0 acpi0 33283 380350 0 0 3 0x40014200 idle1 72794 326609 0 0 3 0x14200 bored softnet1 86433 335867 0 0 3 0x14200 bored softnet0 80709 427095 0 0 3 0x14200 smrbar systqmp 56414 493534 0 0 3 0x14200 bored systq *99333 28393 0 0 7 0x14200 softclockmp 70468 225708 0 0 3 0x40014200 tmoslp softclock 31486 148940 0 0 3 0x40014200 idle0 1 387584 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{1}> show all locks Process 80709 (systqmp) thread 0xffff8000ffffea60 (427095) shared rwlock systqmp r = 0 (0xffffffff83892ca8) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 taskq_thread+0x12a sys/kern/kern_task.c:442 #2 proc_trampoline+0x10 Process 99333 (softclockmp) thread 0xffff8000ffffe298 (28393) exclusive rwlock maddr r = 0 (0xffff8000015a7878) #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 11080 12170K 12432K 166960K 12994 0 pcb 18 12K 12K 166960K 91 0 rtable 223 8K 9K 166960K 458 0 pf 34 17K 81K 166960K 99 0 ifaddr 40 6K 8K 166960K 70 0 ifgroup 55 2K 2K 166960K 106 0 sysctl 4 1K 9K 166960K 9 0 counters 70 37K 37K 166960K 120 0 ioctlops 0 0K 4K 166960K 1638 0 iov 0 0K 16K 166960K 26 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1402 88K 89K 166960K 1884 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 6 0 VM map 2 1K 1K 166960K 2 0 sem 11 0K 0K 166960K 16 0 dirhash 12 2K 2K 166960K 24 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 85K 166960K 615 0 sigio 0 0K 0K 166960K 6 0 proc 72 115K 148K 166960K 602 0 subproc 72 4K 4K 166960K 82 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 2 0K 0K 166960K 204 0 in_multi 84 6K 7K 166960K 120 0 ether_multi 1 0K 0K 166960K 4 0 mrt 4 0K 0K 166960K 4 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 127 572K 572K 166960K 127 0 exec 0 0K 1K 166960K 502 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 253 160K 178K 166960K 7278 0 UVM aobj 12 6K 6K 166960K 16 0 pinsyscall 43 86K 101K 166960K 1770 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 33 0 NDP 12 0K 1K 166960K 48 0 temp 79 8680K 8752K 166960K 33177 0 kqueue 13 20K 28K 166960K 130 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 120 206 0 203 3 0 3 3 0 8 2 rtentry 176 132 0 38 6 0 6 6 0 8 0 unpcb 144 387 0 370 7 1 6 6 0 8 5 syncache 336 5 0 5 2 1 1 1 0 8 1 tcpcb 736 235 0 230 7 6 1 7 0 8 0 arp 136 21 0 4 1 0 1 1 0 8 0 inpcb 328 711 0 701 9 5 4 7 0 8 2 nd6 152 31 0 7 1 0 1 1 0 8 0 pkpcb 40 4 0 4 1 0 1 1 0 8 1 kcovpl 48 9 0 1 1 0 1 1 0 8 0 mppekey 1024 2 0 2 1 0 1 1 0 8 1 ppxss 1192 19 0 19 1 0 1 1 0 8 1 pppxif 1576 1 0 1 1 1 0 1 0 8 0 pffrag 232 8 0 0 1 0 1 1 0 482 0 pffrnode 88 8 0 0 1 0 1 1 0 8 0 pffrent 40 10 0 2 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 59 0 8 1 0 1 1 0 8 0 pfstkey 128 59 0 8 2 0 2 2 0 8 0 pfstate 448 59 0 8 7 0 7 7 0 8 0 pfrule 1344 21 0 16 2 1 1 2 0 8 0 rttmr 136 2 0 0 1 0 1 1 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 544 0 137 29 1 28 29 0 8 2 art_table 40 546 0 137 5 0 5 5 0 8 0 art_node 32 132 0 47 1 0 1 1 0 8 0 sysvmsgpl 40 8 0 6 1 0 1 1 0 8 0 semupl 112 1 0 1 1 0 1 1 0 8 1 semapl 112 12 0 3 1 0 1 1 0 8 0 shmpl 112 10 0 3 1 0 1 1 0 8 0 dirhash 1024 25 0 8 3 0 3 3 0 8 0 dino2pl 256 2538 0 1034 96 0 96 96 0 8 0 ffsino 296 2538 0 1034 118 0 118 118 0 8 0 nchpl 144 3395 0 1690 64 0 64 64 0 8 0 rtmask 32 3 0 3 2 1 1 1 0 8 1 vnodes 216 2928 0 0 163 0 163 163 0 8 0 namei 1024 11755 0 11755 2 1 1 2 0 8 1 percpumem 16 75 0 25 1 0 1 1 0 8 0 vcpupl 3968 2 0 0 1 0 1 1 0 8 0 vmpool 848 3 0 1 1 0 1 1 0 8 0 kstatmem 264 64 0 36 3 0 3 3 0 8 1 acpiwqpl 32 1 0 1 1 0 1 1 1 8 1 scsiplug 72 5 0 5 2 1 1 1 0 8 1 scxspl 216 13860 0 13860 10 3 7 8 1 8 7 plimitpl 152 128 0 109 1 0 1 1 0 8 0 sigapl 424 923 0 875 6 0 6 6 0 8 0 knotepl 120 329 0 0 10 0 10 10 0 8 0 kqueuepl 224 320 0 309 6 1 5 5 0 8 4 pipepl 344 159 0 132 3 0 3 3 0 8 0 fdescpl 528 906 0 874 3 0 3 3 0 8 0 filepl 160 5803 0 5573 17 1 16 16 0 8 5 lockfpl 104 152 0 150 1 0 1 1 0 8 0 lockfspl 48 72 0 70 1 0 1 1 0 8 0 sessionpl 144 24 0 15 1 0 1 1 0 8 0 pgrppl 48 41 0 23 1 0 1 1 0 8 0 ucredpl 104 599 0 586 1 0 1 1 0 8 0 zombiepl 144 877 0 875 1 0 1 1 0 8 0 processpl 1232 923 0 875 5 1 4 5 0 8 0 procpl 664 1747 0 1686 6 0 6 6 0 8 0 sosppl 176 2 0 2 2 1 1 1 0 8 1 sockpl 752 1330 0 1300 19 8 11 17 0 8 7 mcl64k 65536 16 0 0 2 0 2 2 0 8 0 mcl16k 16384 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 112 0 0 14 0 14 14 0 8 0 mcl2k 2048 45 0 0 6 0 6 6 0 8 0 mtagpl 96 15 0 0 1 0 1 1 0 8 0 mbufpl 256 230 0 0 15 0 15 15 0 8 0 bufpl 280 4813 0 132 335 0 335 335 0 8 0 anonpl 32 9272 0 0 75 0 75 75 0 246 0 amapchunkpl 152 23983 0 23334 32 0 32 32 0 158 2 amappl16 200 3068 0 3031 19 6 13 16 0 8 8 amappl15 192 5 0 5 1 1 0 1 0 8 0 amappl14 184 77 0 77 2 2 0 1 0 8 0 amappl13 176 440 0 439 1 0 1 1 0 8 0 amappl12 168 1275 0 1232 3 0 3 3 0 8 0 amappl11 160 4 0 4 2 1 1 1 0 8 1 amappl10 152 49 0 35 1 0 1 1 0 8 0 amappl9 144 251 0 251 1 1 0 1 0 8 0 amappl8 136 34 0 32 1 0 1 1 0 8 0 amappl7 128 82 0 80 1 0 1 1 0 8 0 amappl6 120 291 0 278 1 0 1 1 0 8 0 amappl5 112 78 0 67 1 0 1 1 0 8 0 amappl4 104 428 0 396 1 0 1 1 0 8 0 amappl3 96 4023 0 3926 3 0 3 3 0 8 0 amappl2 88 1020 0 942 2 0 2 2 0 8 0 amappl1 80 11384 0 10791 15 1 14 14 0 8 0 amappl 88 6457 0 6281 5 0 5 5 0 92 0 uvmvnodes 80 115 0 0 3 0 3 3 0 8 0 dma65536 65536 1 0 1 1 0 1 1 0 8 1 dma32768 32768 1 0 1 1 1 0 1 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 128 254 0 254 2 2 0 1 0 8 0 dma64 64 7 0 7 2 1 1 1 0 8 1 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 15 0 4 1 0 1 1 0 8 0 uaddrrnd 24 906 0 874 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 906 0 874 1 0 1 1 0 8 0 vmmpekpl 168 8978 0 8939 3 0 3 3 0 8 1 vmmpepl 168 64330 0 62331 100 1 99 99 0 357 9 vmsppl 488 905 0 874 6 1 5 5 0 8 1 rwobjpl 80 19877 0 18807 28 0 28 28 0 8 1 pdppl 4096 1826 0 1752 100 25 75 82 0 8 1 pvpl 32 17281 0 0 142 2 140 141 0 265 0 pmappl 256 908 0 875 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 296 0 37 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: 0x7a185fc4b100, 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: 0x7a185fc4b100, 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(ffff8000015a7878,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854 rw_do_enter_read(ffff8000015a7860,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355 in6_hasmulti(fffffd80692f93f0,ffff8000015a7800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd80692f93f0,ffff8000015a7800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd80692f9300,ffffffff839eee58,0,0,ffff80002a1fece0,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff80000154c100,83,0) 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(ffff8000ffffe298) 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(ffff8000015a7878,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854 rw_do_enter_read(ffff8000015a7860,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355 in6_hasmulti(fffffd80692f93f0,ffff8000015a7800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd80692f93f0,ffff8000015a7800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd80692f9300,ffffffff839eee58,0,0,ffff80002a1fece0,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff80000154c100,83,0) 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(ffff8000ffffe298) at softclock_thread_mp+0x86 end trace frame: 0x0, count: -12