panic: maddr rwlock 0xffff800001569860: enter read deadlock Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 35949 68700 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(ffff800001569860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd8067eda3f0,ffff800001569800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd8067eda3f0,ffff800001569800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd8067eda300,ffffffff839adbf8,0,0,ffff80002a739130,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff800001527780,83,0) 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(ffff80002a72c530) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72c530) 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 0xffff800001569860: 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(ffff800001569860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd8067eda3f0,ffff800001569800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd8067eda3f0,ffff800001569800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd8067eda300,ffffffff839adbf8,0,0,ffff80002a739130,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff800001527780,83,0) 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(ffff80002a72c530) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72c530) at softclock_thread+0x12b sys/kern/kern_timeout.c:866 end trace frame: 0x0, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002a738e40 rbx 0xffff800001569800 rdx 0 rcx 0 rax 0xffff80002a72c530 r8 0x101010101010101 r9 0x8080808080808080 r10 0x1f1c50c3decb796a r11 0x6457b127fb0813ee r12 0 r13 0xffff80002a72c534 r14 0 r15 0x1 rip 0xffffffff82215455 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a738e30 ss 0 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (softclock) tid=35949 pid=68700 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=0xffff80002a72c7c8,0xffff80002a72c010 process=0xffff8000ffffd200 user=0xffff80002a734000, vmspace=0xffffffff839ad710 estcpu=0, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 77405 456575 29234 0 2 0 syz-executor 77405 356317 29234 0 3 0x4000000 inode syz-executor 19940 244770 729 0 2 0 syz-executor 19940 1588 729 0 3 0x4000000 inode syz-executor 91858 367895 71828 -1 2 0x10 syz-executor 91858 104751 71828 -1 3 0x4000090 fsleep syz-executor 48162 409791 43497 0 3 0x80 nanoslp syz-executor 48162 224636 43497 0 3 0x4000080 bell syz-executor 95256 519446 35863 0 2 0x400000 syz-executor 95256 375039 35863 0 3 0x4400080 fsleep syz-executor 30032 193284 23882 0 2 0 syz-executor 30032 519165 23882 0 3 0x4000080 sbwait syz-executor 30032 128234 23882 0 3 0x4000080 fsleep syz-executor 91369 61022 0 0 3 0x14280 nfsidl nfsio 193 112580 0 0 3 0x14280 nfsidl nfsio 27044 208460 0 0 3 0x14280 nfsidl nfsio 73130 316521 0 0 3 0x14280 nfsidl nfsio 25736 517879 0 0 3 0x14280 nfsidl nfsio 401 299431 0 0 3 0x14280 nfsidl nfsio 85992 503087 0 0 3 0x14280 nfsidl nfsio 14942 60845 0 0 3 0x14280 nfsidl nfsio 7056 427764 0 0 3 0x14280 nfsidl nfsio 96514 402872 0 0 3 0x14280 nfsidl nfsio 42632 504421 0 0 3 0x14280 nfsidl nfsio 28162 57866 0 0 3 0x14280 nfsidl nfsio 17957 328541 0 0 3 0x14280 nfsidl nfsio 99325 345856 0 0 3 0x14280 nfsidl nfsio 54042 449153 0 0 3 0x14280 nfsidl nfsio 48270 509692 0 0 3 0x14280 nfsidl nfsio 87028 244582 0 0 3 0x14280 nfsidl nfsio 94988 499994 0 0 3 0x14280 nfsidl nfsio 29467 332774 0 0 3 0x14280 nfsidl nfsio 21578 521621 0 0 3 0x14280 nfsidl nfsio 66609 486548 46453 0 2 0 syz-executor 66609 201967 46453 0 3 0x4000000 biowait syz-executor 66609 93154 46453 0 3 0x4000080 fsleep syz-executor 70841 143504 65701 0 2 0 syz-executor 70841 50102 65701 0 2 0x4000000 syz-executor 70841 237672 65701 0 3 0x4000080 fsleep syz-executor 23882 345066 96319 0 2 0xc82 syz-executor 46453 347973 96319 0 3 0x82 nanoslp syz-executor 35863 240446 96319 0 2 0xc82 syz-executor 65701 246715 96319 0 3 0x82 nanoslp syz-executor 71828 256281 96319 0 3 0x82 nanoslp syz-executor 29234 178395 96319 0 3 0x82 nanoslp syz-executor 43497 2971 96319 0 2 0xc82 syz-executor 729 254481 96319 0 3 0x82 nanoslp syz-executor 96319 41623 61938 0 3 0x82 kqread syz-executor 61938 460233 5762 0 3 0x10008a sigsusp ksh 5762 239031 6965 0 3 0x98 kqread sshd-session 6965 82272 14990 0 3 0x92 kqread sshd-session 70017 42060 1 0 3 0x100083 ttyin getty 14990 309520 1 0 3 0x88 kqread sshd 44662 444776 11035 73 3 0x1100090 kqread syslogd 11035 359681 1 0 3 0x100082 sbwait syslogd 62486 386817 1 0 3 0x100080 kqread resolvd 59815 157609 58005 77 3 0x100092 kqread dhcpleased 25868 330407 58005 77 3 0x100092 kqread dhcpleased 58005 370238 1 0 3 0x80 kqread dhcpleased 42700 386243 0 0 3 0x14200 bored smr 81066 248296 0 0 2 0x14200 zerothread 97045 353220 0 0 3 0x14200 aiodoned aiodoned 3620 72726 0 0 3 0x14200 syncer update 36212 235179 0 0 3 0x14200 cleaner cleaner 14716 292042 0 0 3 0x14200 reaper reaper 4185 371308 0 0 3 0x14200 pgdaemon pagedaemon 26870 228441 0 0 3 0x14200 bored viomb 88628 441299 0 0 3 0x40014200 acpi0 acpi0 61531 155902 0 0 3 0x14200 bored softnet0 4466 474289 0 0 3 0x14200 bored systqmp 63918 437999 0 0 3 0x14200 bored systq *68700 35949 0 0 7 0x40014200 softclock 32305 25604 0 0 3 0x40014200 idle0 1 54998 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11038 12292K 12308K 166960K 12175 0 pcb 19 12K 12K 166960K 29 0 rtable 245 7K 7K 166960K 379 0 pf 30 12K 14K 166960K 37 0 ifaddr 42 7K 7K 166960K 48 0 ifgroup 50 2K 2K 166960K 59 0 sysctl 3 1K 9K 166960K 7 0 counters 33 17K 18K 166960K 37 0 ioctlops 0 0K 4K 166960K 34 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1405 88K 89K 166960K 1500 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 3 0 VM map 2 1K 1K 166960K 2 0 sem 2 0K 0K 166960K 2 0 dirhash 12 2K 2K 166960K 12 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 89K 166960K 172 0 proc 60 59K 91K 166960K 480 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 3 0 in_multi 99 7K 7K 166960K 102 0 ether_multi 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 362 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 238 143K 150K 166960K 3218 0 UVM aobj 3 2K 2K 166960K 3 0 pinsyscall 39 78K 92K 166960K 1240 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 2 0 NDP 11 0K 1K 166960K 30 0 temp 35 8658K 8722K 166960K 3984 0 kqueue 13 20K 22K 166960K 26 0 SYN cache 2 16K 16K 166960K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 42 0 39 1 0 1 1 0 8 0 rtentry 136 115 0 5 4 0 4 4 0 8 0 unpcb 144 97 0 74 2 0 2 2 0 8 0 syncache 336 3 0 3 1 0 1 1 0 8 1 tcpcb 736 16 0 11 1 0 1 1 0 8 0 arp 96 19 0 1 1 0 1 1 0 8 0 inpcb 328 81 0 70 1 0 1 1 0 8 0 ip6q 72 1 0 1 1 0 1 1 0 8 1 ip6af 40 2 0 2 1 0 1 1 0 8 1 nd6 112 25 0 0 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 0 1 1 0 8 1 kcovpl 48 8 0 0 1 0 1 1 0 8 0 ppxss 1072 3 0 3 1 0 1 1 0 8 1 pppxif 1416 1 0 1 1 0 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 461 0 8 29 0 29 29 0 8 0 art_table 40 462 0 8 5 0 5 5 0 8 0 art_node 32 115 0 15 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1634 0 127 95 0 95 95 0 8 0 ffsino 256 1634 0 127 95 0 95 95 0 8 0 nchpl 144 1876 0 183 64 0 64 64 0 8 0 vnodes 216 1829 0 0 102 0 102 102 0 8 0 namei 1024 5464 0 5461 2 0 2 2 0 8 1 kstatmem 264 28 0 6 2 0 2 2 0 8 0 scxspl 216 6390 0 6389 2 0 2 2 1 8 1 plimitpl 152 31 0 12 1 0 1 1 0 8 0 sigapl 424 718 0 655 34 18 16 34 0 8 8 knotepl 120 3640 0 3593 2 0 2 2 0 8 0 kqueuepl 184 29 0 20 1 0 1 1 0 8 0 pipepl 304 181 0 154 8 0 8 8 0 8 5 fdescpl 448 445 0 415 5 0 5 5 0 8 1 filepl 120 1851 0 1628 13 0 13 13 0 8 5 lockfpl 104 13 0 10 1 0 1 1 0 8 0 lockfspl 48 8 0 5 1 0 1 1 0 8 0 sessionpl 144 21 0 13 1 0 1 1 0 8 0 pgrppl 48 29 0 13 1 0 1 1 0 8 0 ucredpl 104 145 0 132 1 0 1 1 0 8 0 zombiepl 144 655 0 655 1 0 1 1 0 8 1 processpl 1152 718 0 655 22 9 13 22 0 8 8 procpl 664 777 0 703 26 11 15 26 0 8 8 sockpl 552 221 0 184 5 0 5 5 0 8 1 mcl64k 65536 2 0 2 1 0 1 1 0 8 1 mcl8k 8192 5 0 5 1 0 1 1 0 8 1 mcl4k 4096 2498 0 2447 15 0 15 15 0 8 8 mcl2k 2048 249 0 246 4 0 4 4 0 8 3 mtagpl 96 5 0 4 1 0 1 1 0 8 0 mbufpl 256 4455 0 4294 15 0 15 15 0 8 0 bufpl 280 2290 0 119 156 0 156 156 0 8 0 anonpl 24 98438 0 95249 32 0 32 32 0 187 10 amapchunkpl 152 9305 0 8784 25 0 25 25 0 158 4 amappl16 200 1678 0 1658 5 0 5 5 0 8 3 amappl15 192 5 0 5 1 0 1 1 0 8 1 amappl14 184 4 0 4 1 0 1 1 0 8 1 amappl13 176 406 0 405 1 0 1 1 0 8 0 amappl12 168 778 0 739 2 0 2 2 0 8 0 amappl11 160 21 0 21 1 0 1 1 0 8 1 amappl10 152 47 0 37 1 0 1 1 0 8 0 amappl9 144 251 0 250 1 0 1 1 0 8 0 amappl8 136 27 0 26 1 0 1 1 0 8 0 amappl7 128 80 0 79 1 0 1 1 0 8 0 amappl6 120 256 0 245 1 0 1 1 0 8 0 amappl5 112 67 0 60 1 0 1 1 0 8 0 amappl4 104 376 0 352 1 0 1 1 0 8 0 amappl3 96 1441 0 1342 3 0 3 3 0 8 0 amappl2 88 555 0 481 2 0 2 2 0 8 0 amappl1 80 8945 0 8404 13 0 13 13 0 8 1 amappl 88 2526 0 2356 4 0 4 4 0 92 0 uvmvnodes 80 97 0 0 2 0 2 2 0 8 0 dma4096 4096 1 0 1 1 0 1 1 0 8 1 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 6 0 6 1 0 1 1 0 8 1 dma128 128 253 0 253 1 0 1 1 0 8 1 dma64 64 6 0 6 1 0 1 1 0 8 1 dma32 32 7 0 7 1 0 1 1 0 8 1 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 24 445 0 415 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 445 0 415 1 0 1 1 0 8 0 vmmpekpl 168 6070 0 6034 3 0 3 3 0 8 0 vmmpepl 168 36083 0 34263 81 0 81 81 0 357 1 vmsppl 368 444 0 415 4 0 4 4 0 8 1 rwobjpl 40 13161 0 12217 10 0 10 10 0 8 0 pdppl 4096 897 0 830 93 24 69 79 0 8 2 pvpl 32 222617 0 213612 98 0 98 98 0 265 22 pmappl 216 444 0 415 2 0 2 2 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 368 0 24 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(ffff800001569860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd8067eda3f0,ffff800001569800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd8067eda3f0,ffff800001569800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd8067eda300,ffffffff839adbf8,0,0,ffff80002a739130,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff800001527780,83,0) 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(ffff80002a72c530) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72c530) 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(ffff800001569860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd8067eda3f0,ffff800001569800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd8067eda3f0,ffff800001569800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd8067eda300,ffffffff839adbf8,0,0,ffff80002a739130,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff800001527780,83,0) 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(ffff80002a72c530) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72c530) at softclock_thread+0x12b sys/kern/kern_timeout.c:866 end trace frame: 0x0, count: -10