panic: maddr rwlock 0xffff80000155d860: enter read deadlock Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *507722 93703 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83325ab2) at panic+0x1cf sys/kern/subr_prf.c:198 rw_do_enter_read(ffff80000155d860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd806c90d2f0,ffff80000155d800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd806c90d2f0,ffff80000155d800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd806c90d200,ffffffff839adbf8,0,0,ffff80002a739cc0,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff80000152ca00,83,0) at mld6_sendpkt+0x364 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(ffffffff838bf828) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1 timeout_run(ffffffff837b82a0,ffffffff838bf828) at timeout_run+0xf3 sys/kern/kern_timeout.c:-1 softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b sys/kern/kern_timeout.c:866 end trace frame: 0x0, count: 5 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> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic *cpu0: maddr rwlock 0xffff80000155d860: enter read deadlock ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83325ab2) at panic+0x1cf sys/kern/subr_prf.c:198 rw_do_enter_read(ffff80000155d860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd806c90d2f0,ffff80000155d800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd806c90d2f0,ffff80000155d800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd806c90d200,ffffffff839adbf8,0,0,ffff80002a739cc0,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff80000152ca00,83,0) at mld6_sendpkt+0x364 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(ffffffff838bf828) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1 timeout_run(ffffffff837b82a0,ffffffff838bf828) at timeout_run+0xf3 sys/kern/kern_timeout.c:-1 softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b sys/kern/kern_timeout.c:866 end trace frame: 0x0, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002a7399d0 rbx 0xffff80000155d800 rdx 0 rcx 0 rax 0xffff80002a72cf90 r8 0x101010101010101 r9 0x8080808080808080 r10 0x46abe56e89e4eccd r11 0x53d2f29b96d7fec2 r12 0 r13 0xffff80002a72cf94 r14 0 r15 0x1 rip 0xffffffff82215455 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a7399c0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (softclock) tid=507722 pid=93703 tcnt=1 stat=onproc flags process=14000 proc=40000200 runpri=0, usrpri=50, slppri=0, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a72d4c0,0xffff80002a72cd08 process=0xffff8000ffffdf80 user=0xffff80002a734000, vmspace=0xffffffff839ad710 estcpu=0, cpticks=1, pctcpu=0.0, user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 84772 8457 66156 0 3 0x80 nanoslp syz-executor 84772 50567 66156 0 3 0x4000080 tunread syz-executor 84772 414788 66156 0 3 0x4000080 fsleep syz-executor 62846 409662 45937 0 3 0x80 nanoslp syz-executor 62846 322141 45937 0 3 0x4000080 ttyin syz-executor 62846 102094 45937 0 3 0x4000080 fsleep syz-executor 70154 489918 77006 0 2 0xc80 syz-executor 70154 43671 77006 0 3 0x4000080 lockf syz-executor 70154 239546 77006 0 3 0x4000080 lockf syz-executor 70154 49340 77006 0 3 0x4000080 fsleep syz-executor 86208 481034 42918 0 3 0x80 nanoslp syz-executor 86208 13428 42918 0 3 0x4000080 sbwait syz-executor 86208 369075 42918 0 3 0x4000080 fsleep syz-executor 66156 235342 85214 0 3 0x82 nanoslp syz-executor 32040 61991 0 0 3 0x14200 acct acct 23561 338134 0 0 3 0x14280 nfsidl nfsio 23288 625 0 0 3 0x14280 nfsidl nfsio 62564 105156 0 0 3 0x14280 nfsidl nfsio 58811 112431 0 0 3 0x14280 nfsidl nfsio 1636 381514 0 0 3 0x14280 nfsidl nfsio 12664 166674 0 0 3 0x14280 nfsidl nfsio 66717 137497 0 0 3 0x14280 nfsidl nfsio 98887 378742 0 0 3 0x14280 nfsidl nfsio 40852 317387 0 0 3 0x14280 nfsidl nfsio 47349 247411 0 0 3 0x14280 nfsidl nfsio 39185 454599 0 0 3 0x14280 nfsidl nfsio 25637 87272 0 0 3 0x14280 nfsidl nfsio 64582 423868 0 0 3 0x14280 nfsidl nfsio 74571 238274 0 0 3 0x14280 nfsidl nfsio 19630 366143 0 0 3 0x14280 nfsidl nfsio 39222 368743 0 0 3 0x14280 nfsidl nfsio 87251 308833 0 0 3 0x14280 nfsidl nfsio 72132 523881 0 0 3 0x14280 nfsidl nfsio 23819 292791 0 0 3 0x14280 nfsidl nfsio 25613 266692 0 0 3 0x14280 nfsidl nfsio 2646 79971 85214 0 2 0xc82 syz-executor 42918 317169 85214 0 3 0x82 nanoslp syz-executor 77006 452829 85214 0 3 0x82 nanoslp syz-executor 96782 516546 85214 0 3 0x82 nanoslp syz-executor 36951 227612 85214 0 3 0x82 nanoslp syz-executor 45937 331068 85214 0 3 0x82 nanoslp syz-executor 8813 509979 85214 0 3 0x82 wait syz-executor 85214 389794 70240 0 3 0x82 kqread syz-executor 70240 317875 96146 0 3 0x10008a sigsusp ksh 96146 329149 62974 0 3 0x98 kqread sshd-session 62974 430582 91775 0 3 0x92 kqread sshd-session 62042 416263 1 0 3 0x100083 ttyopn getty 91775 428971 1 0 3 0x88 kqread sshd 50223 285670 55498 73 3 0x1100090 kqread syslogd 55498 448579 1 0 3 0x100082 sbwait syslogd 29786 91237 1 0 3 0x100080 kqread resolvd 24401 417598 7635 77 3 0x100092 kqread dhcpleased 23963 204582 7635 77 3 0x100092 kqread dhcpleased 7635 235365 1 0 3 0x80 kqread dhcpleased 81126 417308 0 0 3 0x14200 bored smr 27191 480120 0 0 3 0x14200 pgzero zerothread 39994 84863 0 0 3 0x14200 aiodoned aiodoned 29939 382158 0 0 3 0x14200 syncer update 61777 477096 0 0 3 0x14200 cleaner cleaner 43774 476413 0 0 3 0x14200 reaper reaper 92918 41396 0 0 3 0x14200 pgdaemon pagedaemon 16181 138320 0 0 3 0x14200 bored viomb 89132 49399 0 0 3 0x40014200 acpi0 acpi0 27417 468343 0 0 3 0x14200 bored softnet0 88432 222447 0 0 3 0x14200 bored systqmp 75739 365046 0 0 3 0x14200 bored systq *93703 507722 0 0 7 0x40014200 softclock 6085 383104 0 0 3 0x40014200 idle0 1 517764 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11045 12168K 12495K 166960K 13637 0 pcb 18 15K 16K 166960K 168 0 rtable 270 11K 11K 166960K 480 0 pf 37 14K 17K 166960K 187 0 ifaddr 45 8K 8K 166960K 75 0 ifgroup 55 2K 2K 166960K 107 0 sysctl 4 1K 9K 166960K 13 0 counters 34 17K 18K 166960K 65 0 ioctlops 0 0K 4K 166960K 151 0 iov 0 0K 26K 166960K 31 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1409 89K 89K 166960K 2057 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 9K 166960K 17 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 86 0 dirhash 12 2K 2K 166960K 33 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 93K 166960K 651 0 sigio 0 0K 0K 166960K 8 0 proc 60 59K 108K 166960K 545 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 2 0K 0K 166960K 56 0 in_multi 103 7K 7K 166960K 142 0 ether_multi 1 0K 0K 166960K 9 0 mrt 1 0K 0K 166960K 7 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 115 519K 519K 166960K 115 0 exec 0 0K 1K 166960K 427 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 249 160K 191K 166960K 7463 0 UVM aobj 26 4K 6K 166960K 29 0 pinsyscall 39 78K 92K 166960K 1780 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 30 0 NDP 12 0K 2K 166960K 50 0 temp 79 8672K 8748K 166960K 27437 0 kqueue 16 24K 28K 166960K 127 0 SYN cache 2 0K 16K 166960K 4 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 73 0 70 1 0 1 1 0 8 0 rtentry 136 135 0 23 4 0 4 4 0 8 0 unpcb 144 391 0 371 2 0 2 2 0 8 1 syncache 336 10 0 10 2 1 1 1 0 8 1 tcpqe 32 1 0 1 1 1 0 1 0 8 0 tcpcb 736 219 0 209 8 1 7 7 0 8 6 arp 96 20 0 2 1 0 1 1 0 8 0 ipq 40 3 0 0 1 0 1 1 0 8 0 ipqe 40 3 0 0 1 0 1 1 0 8 0 inpcb 328 746 0 730 8 1 7 7 0 8 5 ip6q 72 3 0 2 1 0 1 1 0 8 0 ip6af 40 5 0 4 1 0 1 1 0 8 0 nd6 112 29 0 4 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 0 1 1 0 8 1 kcovpl 48 9 0 1 1 0 1 1 0 8 0 mppekey 1024 1 0 1 1 0 1 1 0 8 1 ppxss 1072 25 0 25 1 0 1 1 0 8 1 pppxif 1416 6 0 6 1 0 1 1 0 8 1 pfrktable 1344 4 0 2 1 0 1 1 0 8 0 pfanchor 1288 1 0 0 1 0 1 1 0 8 0 pftag 88 2 0 0 1 0 1 1 0 8 0 pfstitem 24 2 0 0 1 0 1 1 0 8 0 pfstkey 128 6 0 4 1 0 1 1 0 8 0 pfstate 384 4 0 3 1 0 1 1 0 8 0 pfrule 1344 37 0 4 3 0 3 3 0 8 0 rttmr 136 1 0 1 1 0 1 1 0 8 1 art_heap8 4096 3 0 0 3 0 3 3 0 8 0 art_heap4 256 564 0 101 31 0 31 31 0 8 2 art_table 40 567 0 101 5 0 5 5 0 8 0 art_node 32 133 0 32 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 4 2 1 1 1 0 8 1 semupl 112 1 0 1 1 0 1 1 0 8 1 semapl 112 83 0 73 1 0 1 1 0 8 0 shmpl 112 25 0 2 1 0 1 1 0 8 0 dirhash 1024 31 0 14 3 0 3 3 0 8 0 dino2pl 256 2540 0 1035 95 0 95 95 0 8 0 ffsino 256 2540 0 1035 95 0 95 95 0 8 0 nchpl 144 3425 0 1727 64 0 64 64 0 8 0 rtmask 32 4 0 4 1 0 1 1 0 8 1 vnodes 216 3099 0 0 173 0 173 173 0 8 0 namei 1024 11132 0 11132 3 2 1 2 0 8 1 vmpool 808 1 0 1 1 0 1 1 0 8 1 pfiaddrpl 120 33 0 0 1 0 1 1 0 8 0 kstatmem 264 60 0 36 2 0 2 2 0 8 0 acpiwqpl 32 1 0 1 1 0 1 1 1 8 1 scsiplug 72 1 0 1 1 0 1 1 0 8 1 scxspl 216 11133 0 11133 9 1 8 8 1 8 8 plimitpl 152 110 0 91 1 0 1 1 0 8 0 sigapl 424 964 0 900 8 0 8 8 0 8 0 knotepl 120 28781 0 28731 16 7 9 9 0 8 7 kqueuepl 184 275 0 261 3 0 3 3 0 8 2 pipepl 304 296 0 269 8 0 8 8 0 8 5 fdescpl 448 930 0 900 5 1 4 5 0 8 0 filepl 120 5447 0 5204 14 1 13 13 0 8 5 lockfpl 104 319 0 314 2 0 2 2 0 8 1 lockfspl 48 148 0 145 1 0 1 1 0 8 0 sessionpl 144 27 0 19 1 0 1 1 0 8 0 pgrppl 48 40 0 24 1 0 1 1 0 8 0 ucredpl 104 905 0 891 1 0 1 1 0 8 0 zombiepl 144 904 0 900 1 0 1 1 0 8 0 processpl 1152 964 0 900 5 0 5 5 0 8 0 procpl 664 1708 0 1635 7 0 7 7 0 8 0 sosppl 176 5 0 5 2 1 1 1 0 8 1 sockpl 552 1232 0 1193 8 0 8 8 0 8 5 mcl64k 65536 33 0 32 1 0 1 1 0 8 0 mcl16k 16384 1 0 1 1 1 0 1 0 8 0 mcl12k 12288 1 0 1 1 1 0 1 0 8 0 mcl8k 8192 12 0 12 2 1 1 1 0 8 1 mcl4k 4096 3124 0 3066 15 7 8 15 0 8 0 mcl2k2 2112 1 0 1 1 1 0 1 0 8 0 mcl2k 2048 1096 0 1092 2 0 2 2 0 8 1 mtagpl 96 36 0 12 1 0 1 1 0 8 0 mbufpl 256 10020 0 9838 17 0 17 17 0 8 4 bufpl 280 3517 0 119 243 0 243 243 0 8 0 anonpl 24 157267 0 153958 55 12 43 43 0 187 18 amapchunkpl 152 24569 0 24039 37 9 28 29 0 158 6 amappl16 200 2383 0 2355 6 3 3 5 0 8 1 amappl15 192 11 0 11 1 1 0 1 0 8 0 amappl14 184 5 0 5 1 1 0 1 0 8 0 amappl13 176 421 0 420 1 0 1 1 0 8 0 amappl12 168 1291 0 1252 2 0 2 2 0 8 0 amappl11 160 3 0 3 1 1 0 1 0 8 0 amappl10 152 43 0 33 1 0 1 1 0 8 0 amappl9 144 268 0 268 1 1 0 1 0 8 0 amappl8 136 21 0 20 1 0 1 1 0 8 0 amappl7 128 89 0 88 1 0 1 1 0 8 0 amappl6 120 279 0 268 1 0 1 1 0 8 0 amappl5 112 79 0 69 1 0 1 1 0 8 0 amappl4 104 424 0 400 1 0 1 1 0 8 0 amappl3 96 4120 0 4022 3 0 3 3 0 8 0 amappl2 88 1080 0 1008 2 0 2 2 0 8 0 amappl1 80 12557 0 12006 15 1 14 14 0 8 1 amappl 88 6602 0 6424 5 0 5 5 0 92 0 uvmvnodes 80 114 0 0 3 0 3 3 0 8 0 dma16384 16384 1 0 1 1 0 1 1 0 8 1 dma4096 4096 2 0 2 1 1 0 1 0 8 0 dma2048 2048 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 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 28 0 3 1 0 1 1 0 8 0 uaddrrnd 24 930 0 900 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 930 0 900 1 0 1 1 0 8 0 vmmpekpl 168 9724 0 9685 3 0 3 3 0 8 0 vmmpepl 168 66458 0 64595 95 7 88 88 0 357 5 vmsppl 368 929 0 900 4 1 3 4 0 8 0 rwobjpl 40 20033 0 19027 12 0 12 12 0 8 0 pdppl 4096 1869 0 1802 99 30 69 81 0 8 2 pvpl 32 416060 0 406563 132 23 109 109 0 265 26 pmappl 216 930 0 901 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 393 0 48 10 0 10 10 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83325ab2) at panic+0x1cf sys/kern/subr_prf.c:198 rw_do_enter_read(ffff80000155d860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd806c90d2f0,ffff80000155d800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd806c90d2f0,ffff80000155d800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd806c90d200,ffffffff839adbf8,0,0,ffff80002a739cc0,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff80000152ca00,83,0) at mld6_sendpkt+0x364 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(ffffffff838bf828) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1 timeout_run(ffffffff837b82a0,ffffffff838bf828) at timeout_run+0xf3 sys/kern/kern_timeout.c:-1 softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b sys/kern/kern_timeout.c:866 end trace frame: 0x0, count: -10 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83325ab2) at panic+0x1cf sys/kern/subr_prf.c:198 rw_do_enter_read(ffff80000155d860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd806c90d2f0,ffff80000155d800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd806c90d2f0,ffff80000155d800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd806c90d200,ffffffff839adbf8,0,0,ffff80002a739cc0,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff80000152ca00,83,0) at mld6_sendpkt+0x364 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(ffffffff838bf828) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1 timeout_run(ffffffff837b82a0,ffffffff838bf828) at timeout_run+0xf3 sys/kern/kern_timeout.c:-1 softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b sys/kern/kern_timeout.c:866 end trace frame: 0x0, count: -10