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 270603 35623 0 0 0 1 syz-executor *326499 79476 0 0x14000 0x200 0 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(ffff8000015a4878,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854 rw_do_enter_read(ffff8000015a4860,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355 in6_hasmulti(fffffd806f86e6f0,ffff8000015a4800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd806f86e6f0,ffff8000015a4800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd806f86e600,ffffffff839eee58,0,0,ffff80002a1fe980,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff8000015ac180,83,0) 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic *cpu0: excl->share ddb{0}> 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(ffff8000015a4878,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854 rw_do_enter_read(ffff8000015a4860,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355 in6_hasmulti(fffffd806f86e6f0,ffff8000015a4800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd806f86e6f0,ffff8000015a4800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd806f86e600,ffffffff839eee58,0,0,ffff80002a1fe980,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff8000015ac180,83,0) 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{0}> show registers rdi 0 rsi 0x1 rbp 0xffff80002a1fe5d0 rbx 0xffffffff837e4e07 cpu_info_full_primary+0x2e07 rdx 0 rcx 0xffff8000ffffe298 rax 0xffffffff837e3ff0 cpu_info_full_primary+0x1ff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0x4be3085002257f9e r11 0x588360b2525323da r12 0xffffffff837e4c08 cpu_info_full_primary+0x2c08 r13 0 r14 0 r15 0x1 rip 0xffffffff810e0165 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a1fe5c0 ss 0 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (softclockmp) tid=326499 pid=79476 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=0xffff8000ffffecf8,0xffff8000ffffe010 process=0xffff8000ffff89a0 user=0xffff80002a1f9000, vmspace=0xffffffff83a0c438 estcpu=0, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 35623 270603 95309 0 7 0 syz-executor 35623 233541 95309 0 2 0x4000000 syz-executor 61602 464316 90209 0 2 0xc80 syz-executor 61602 335877 90209 0 3 0x4000080 fsleep syz-executor 61602 468941 90209 0 3 0x4000080 sbwait syz-executor 16730 489029 57728 0 2 0 syz-executor 16730 216716 57728 0 3 0x4000000 biowait syz-executor 16730 251579 57728 0 2 0x4000000 syz-executor 53871 459834 84850 0 2 0 syz-executor 53871 252111 84850 0 3 0x4000080 fsleep syz-executor 47769 231300 38364 0 2 0xc80 syz-executor 47769 486336 38364 0 3 0x4000080 kqsel syz-executor 47769 225367 38364 0 3 0x4000080 fsleep syz-executor 85938 112934 92087 0 2 0 syz-executor 85938 20595 92087 0 3 0x4000080 fsleep syz-executor 52255 197564 41544 0 3 0x80 nanoslp syz-executor 52255 44696 41544 0 3 0x4000080 semwait syz-executor 52255 60722 41544 0 3 0x4000080 fsleep syz-executor 92087 475408 53133 0 3 0x82 nanoslp syz-executor 90209 218868 53133 0 3 0x82 nanoslp syz-executor 41544 108143 53133 0 3 0x82 nanoslp syz-executor 84850 510061 53133 0 2 0xc82 syz-executor 57728 408437 53133 0 3 0x82 nanoslp syz-executor 95309 342902 53133 0 3 0x82 nanoslp syz-executor 87619 170312 53133 0 3 0x2 biowait syz-executor 38364 480005 53133 0 2 0xc82 syz-executor 53133 381137 94448 0 2 0x82 syz-executor 94448 366786 75833 0 3 0x10008a sigsusp ksh 75833 146953 56255 0 3 0x98 kqread sshd-session 56255 106889 15505 0 3 0x92 kqread sshd-session 98179 226638 1 0 3 0x100083 ttyin getty 15505 339372 1 0 3 0x88 kqread sshd 65647 193347 25373 74 3 0x1100092 bpf pflogd 25373 54065 1 0 3 0x80 sbwait pflogd 86743 325463 71619 73 3 0x1100090 kqread syslogd 71619 402105 1 0 3 0x100082 sbwait syslogd 39377 422949 1 0 3 0x100080 kqread resolvd 95484 378080 44224 77 3 0x100092 kqread dhcpleased 27657 237888 44224 77 3 0x100092 kqread dhcpleased 44224 103430 1 0 3 0x80 kqread dhcpleased 21795 357804 0 0 3 0x14200 bored smr 74980 486574 0 0 2 0x14200 zerothread 13413 222532 0 0 3 0x14200 aiodoned aiodoned 68281 462012 0 0 3 0x14200 syncer update 57697 93528 0 0 3 0x14200 cleaner cleaner 44197 137078 0 0 3 0x14200 reaper reaper 11829 134023 0 0 3 0x14200 pgdaemon pagedaemon 24527 433495 0 0 3 0x14200 bored viomb 88285 16743 0 0 3 0x40014200 acpi0 acpi0 91058 224089 0 0 3 0x40014200 idle1 17597 76550 0 0 3 0x14200 bored softnet1 31391 326434 0 0 3 0x14200 bored softnet0 66542 382910 0 0 3 0x14200 smrbar systqmp 60462 193404 0 0 3 0x14200 bored systq *79476 326499 0 0 7 0x14200 softclockmp 27750 7111 0 0 3 0x40014200 tmoslp softclock 94610 441385 0 0 3 0x40014200 idle0 1 489317 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 16730 (syz-executor) thread 0xffff8000317d2020 (216716) exclusive rrwlock inode r = 0 (0xfffffd806d023a28) #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 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570 #5 vn_write+0x18f sys/kern/vfs_vnops.c:405 #6 dofilewritev+0x242 sys/kern/sys_generic.c:380 #7 sys_write+0xa2 sys/kern/sys_generic.c:300 #8 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #8 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 #9 Xsyscall+0x128 Process 87619 (syz-executor) thread 0xffff8000ffffdc90 (170312) exclusive rrwlock inode r = 0 (0xfffffd806d0230e8) #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 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527 #4 ufs_ihashins+0x4f ufs_ihash sys/ufs/ufs/ufs_ihash.c:-1 [inline] #4 ufs_ihashins+0x4f sys/ufs/ufs/ufs_ihash.c:159 #5 ffs_vget+0x187 sys/ufs/ffs/ffs_vfsops.c:1232 #6 ffs_inode_alloc+0x279 sys/ufs/ffs/ffs_alloc.c:393 #7 ufs_mkdir+0xfc sys/ufs/ufs/ufs_vnops.c:1112 #8 VOP_MKDIR+0x101 sys/kern/vfs_vops.c:394 #9 domkdirat+0x179 sys/kern/vfs_syscalls.c:3113 #10 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #10 syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 #11 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806da941f8) #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 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570 #5 vfs_lookup+0x11c sys/kern/vfs_lookup.c:-1 #6 namei+0x7ca sys/kern/vfs_lookup.c:250 #7 domkdirat+0x8b sys/kern/vfs_syscalls.c:3098 #8 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #8 syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 #9 Xsyscall+0x128 Process 66542 (systqmp) thread 0xffff8000ffffe530 (382910) 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 79476 (softclockmp) thread 0xffff8000ffffe298 (326499) exclusive rwlock maddr r = 0 (0xffff8000015a4878) #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{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11067 12234K 12279K 166960K 12204 0 pcb 20 12K 12K 166960K 29 0 rtable 243 6K 7K 166960K 363 0 pf 34 17K 18K 166960K 45 0 ifaddr 44 7K 7K 166960K 46 0 ifgroup 55 2K 2K 166960K 55 0 sysctl 1 1K 9K 166960K 5 0 counters 70 37K 37K 166960K 70 0 ioctlops 0 0K 4K 166960K 1489 0 iov 0 0K 12K 166960K 8 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1344 85K 85K 166960K 1395 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 1K 166960K 2 0 VM map 2 1K 1K 166960K 2 0 sem 4 0K 0K 166960K 4 0 dirhash 12 2K 2K 166960K 12 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 17 61K 89K 166960K 179 0 sigio 0 0K 0K 166960K 2 0 proc 72 115K 164K 166960K 531 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 2 0 in_multi 99 7K 7K 166960K 101 0 ether_multi 2 0K 0K 166960K 2 0 mrt 1 0K 0K 166960K 1 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 49 228K 228K 166960K 49 0 exec 0 0K 1K 166960K 377 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 248 143K 158K 166960K 3596 0 UVM aobj 3 2K 2K 166960K 3 0 pinsyscall 42 84K 102K 166960K 1306 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 3 0 NDP 19 1K 1K 166960K 28 0 temp 36 8670K 8731K 166960K 4262 0 kqueue 14 22K 26K 166960K 31 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 35 0 31 1 0 1 1 0 8 0 rtentry 176 114 0 1 6 0 6 6 0 8 0 unpcb 144 50 0 33 1 0 1 1 0 8 0 syncache 336 3 0 3 1 0 1 1 0 8 1 tcpcb 736 11 0 7 1 0 1 1 0 8 0 arp 136 19 0 0 1 0 1 1 0 8 0 inpcb 328 92 0 82 2 0 2 2 0 8 1 nd6 152 24 0 0 1 0 1 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 pffrag 232 1 0 0 1 0 1 1 0 482 0 pffrnode 88 1 0 0 1 0 1 1 0 8 0 pffrent 40 1 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 19 0 0 1 0 1 1 0 8 0 pfstkey 128 19 0 0 1 0 1 1 0 8 0 pfstate 448 19 0 0 3 0 3 3 0 8 0 pfrule 1344 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 256 456 0 0 29 0 29 29 0 8 0 art_table 40 457 0 0 5 0 5 5 0 8 0 art_node 32 114 0 11 1 0 1 1 0 8 0 sysvmsgpl 40 1 0 0 1 0 1 1 0 8 0 semapl 112 1 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1644 0 128 96 0 96 96 0 8 0 ffsino 296 1644 0 128 118 0 118 118 0 8 0 nchpl 144 1891 0 192 64 0 64 64 0 8 0 vnodes 216 1749 0 0 98 0 98 98 0 8 0 namei 1024 6027 0 6026 1 0 1 1 0 8 0 percpumem 16 50 0 0 1 0 1 1 0 8 0 kstatmem 264 26 0 0 2 0 2 2 0 8 0 scxspl 216 6280 0 6278 3 1 2 2 1 8 1 plimitpl 152 102 0 83 1 0 1 1 0 8 0 sigapl 424 488 0 441 7 0 7 7 0 8 1 knotepl 120 297 0 0 9 0 9 9 0 8 0 kqueuepl 224 34 0 22 1 0 1 1 0 8 0 pipepl 344 128 0 101 3 0 3 3 0 8 0 fdescpl 528 472 0 441 3 0 3 3 0 8 0 filepl 160 1714 0 1485 10 0 10 10 0 8 0 lockfpl 104 19 0 16 1 0 1 1 0 8 0 lockfspl 48 9 0 6 1 0 1 1 0 8 0 sessionpl 144 22 0 13 1 0 1 1 0 8 0 pgrppl 48 32 0 15 1 0 1 1 0 8 0 ucredpl 104 117 0 104 1 0 1 1 0 8 0 zombiepl 144 441 0 441 1 0 1 1 0 8 1 processpl 1232 488 0 441 5 0 5 5 0 8 0 procpl 664 573 0 515 6 0 6 6 0 8 0 sosppl 176 1 0 1 1 0 1 1 0 8 1 sockpl 752 181 0 150 4 0 4 4 0 8 0 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 124 0 0 16 0 16 16 0 8 0 mcl2k 2048 28 0 0 4 0 4 4 0 8 0 mtagpl 96 2 0 0 1 0 1 1 0 8 0 mbufpl 256 150 0 0 11 1 10 10 0 8 0 bufpl 280 2437 0 130 165 0 165 165 0 8 0 anonpl 32 7659 0 0 62 0 62 62 0 246 0 amapchunkpl 152 10211 0 9622 29 0 29 29 0 158 6 amappl16 200 1956 0 1741 13 1 12 12 0 8 0 amappl15 192 3 0 3 1 1 0 1 0 8 0 amappl14 184 6 0 6 1 1 0 1 0 8 0 amappl13 176 427 0 426 1 0 1 1 0 8 0 amappl12 168 835 0 793 3 0 3 3 0 8 0 amappl11 160 5 0 5 1 1 0 1 0 8 0 amappl10 152 48 0 34 1 0 1 1 0 8 0 amappl9 144 247 0 247 1 1 0 1 0 8 0 amappl8 136 31 0 28 1 0 1 1 0 8 0 amappl7 128 78 0 77 1 0 1 1 0 8 0 amappl6 120 276 0 263 1 0 1 1 0 8 0 amappl5 112 77 0 67 1 0 1 1 0 8 0 amappl4 104 417 0 388 1 0 1 1 0 8 0 amappl3 96 1540 0 1444 4 1 3 3 0 8 0 amappl2 88 580 0 504 2 0 2 2 0 8 0 amappl1 80 9135 0 8543 14 0 14 14 0 8 0 amappl 88 2869 0 2696 5 0 5 5 0 92 1 uvmvnodes 80 99 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 2 0 0 1 0 1 1 0 8 0 uaddrrnd 24 472 0 441 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 472 0 441 1 0 1 1 0 8 0 vmmpekpl 168 5693 0 5661 2 0 2 2 0 8 0 vmmpepl 168 37741 0 35642 92 0 92 92 0 357 0 vmsppl 488 471 0 441 5 0 5 5 0 8 1 rwobjpl 80 13848 0 12627 25 0 25 25 0 8 0 pdppl 4096 952 0 882 96 16 80 84 0 8 10 pvpl 32 13604 0 0 110 0 110 110 0 265 0 pmappl 256 471 0 441 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 270 0 19 8 0 8 8 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(ffffffff833b4a35) at panic+0x1e5 sys/kern/subr_prf.c:198 witness_checkorder(ffff8000015a4878,1,0) at witness_checkorder+0x122c sys/kern/subr_witness.c:854 rw_do_enter_read(ffff8000015a4860,0) at rw_do_enter_read+0x99 sys/kern/kern_rwlock.c:355 in6_hasmulti(fffffd806f86e6f0,ffff8000015a4800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd806f86e6f0,ffff8000015a4800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd806f86e600,ffffffff839eee58,0,0,ffff80002a1fe980,0) at ip6_output+0x13bd sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff8000015ac180,83,0) 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{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 end of kernel end trace frame: 0x797cf9f985f0, count: 12 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 end of kernel end trace frame: 0x797cf9f985f0, count: -3