panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806f15ce00+16 0x0!=0xc6b2fee90a559cd3 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 195243 33412 0 0x2 0x4000000 1 syz-execprog *209207 88245 0 0x14000 0x40000200 0K softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff8261fd98) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff8261fd98) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get() at pool_get+0x91 sys/kern/subr_pool.c:572 m_get(2,1) at m_get+0x4c sys/kern/uipc_mbuf.c:250 mld6_sendpkt(ffff800000a5ee80,83,0) at mld6_sendpkt+0xaf sys/netinet6/mld6.c:410 mld6_fasttimeo() at mld6_fasttimeo+0x162 mld6_checktimer sys/netinet6/mld6.c:363 [inline] mld6_fasttimeo() at mld6_fasttimeo+0x162 sys/netinet6/mld6.c:341 pffasttimo(ffffffff8260fe30) at pffasttimo+0x85 sys/kern/uipc_domain.c:292 timeout_run(ffffffff8260fe30) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff8260fe30) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a10ed0) at softclock_thread+0x16a sys/kern/kern_timeout.c:553 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806f15ce00+16 0x0!=0xc6b2fee90a559cd3 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff8261fd98) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff8261fd98) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get() at pool_get+0x91 sys/kern/subr_pool.c:572 m_get(2,1) at m_get+0x4c sys/kern/uipc_mbuf.c:250 mld6_sendpkt(ffff800000a5ee80,83,0) at mld6_sendpkt+0xaf sys/netinet6/mld6.c:410 mld6_fasttimeo() at mld6_fasttimeo+0x162 mld6_checktimer sys/netinet6/mld6.c:363 [inline] mld6_fasttimeo() at mld6_fasttimeo+0x162 sys/netinet6/mld6.c:341 pffasttimo(ffffffff8260fe30) at pffasttimo+0x85 sys/kern/uipc_domain.c:292 timeout_run(ffffffff8260fe30) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff8260fe30) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a10ed0) at softclock_thread+0x16a sys/kern/kern_timeout.c:553 end trace frame: 0x0, count: -10 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020a24d20 rbx 0xffff800020a24dd0 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffffffff819b290f kprintf+0x16f r9 0x1 r10 0x95eb5cbd9f19ce41 r11 0xe1cfdb325e135310 r12 0x3000000008 r13 0xffff800020a24d30 r14 0x100 r15 0x1 rip 0xffffffff81ec7538 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a24d10 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=209207 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020a11148,0xffff800020a10c68 process=0xffff800020a12700 user=0xffff800020a20000, vmspace=0xffffffff826752d0 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 63449 284010 33412 0 2 0x482 syz-executor.0 33412 157163 12895 0 3 0x82 thrsleep syz-execprog 33412 195243 12895 0 7 0x4000002 syz-execprog 33412 239651 12895 0 3 0x4000082 thrsleep syz-execprog 33412 240479 12895 0 3 0x4000082 thrsleep syz-execprog 33412 63043 12895 0 3 0x4000082 kqread syz-execprog 33412 153505 12895 0 3 0x4000082 thrsleep syz-execprog 33412 271227 12895 0 3 0x4000082 thrsleep syz-execprog 33412 112319 12895 0 2 0x4000482 syz-execprog 33412 389892 12895 0 3 0x4000082 thrsleep syz-execprog 12895 100295 7053 0 3 0x10008a pause ksh 7053 180176 43990 0 3 0x92 select sshd 66519 6354 1 0 3 0x100083 ttyin getty 43990 203369 1 0 3 0x80 select sshd 23208 477449 31303 74 3 0x100092 bpf pflogd 31303 451874 1 0 3 0x80 netio pflogd 75448 316614 16812 73 3 0x100090 kqread syslogd 16812 302352 1 0 3 0x100082 netio syslogd 81699 140050 1 77 3 0x100090 poll dhclient 8921 521490 1 0 3 0x80 poll dhclient 11582 177618 0 0 3 0x14200 pgzero zerothread 23445 298772 0 0 3 0x14200 aiodoned aiodoned 58929 10463 0 0 3 0x14200 syncer update 99523 409015 0 0 3 0x14200 cleaner cleaner 42488 87796 0 0 3 0x14200 reaper reaper 63358 199124 0 0 3 0x14200 pgdaemon pagedaemon 40766 232629 0 0 3 0x14200 bored crynlk 35870 464726 0 0 3 0x14200 bored crypto 78492 517834 0 0 3 0x40014200 acpi0 acpi0 38390 69435 0 0 3 0x40014200 idle1 69208 376574 0 0 3 0x14200 bored softnet 93509 198193 0 0 3 0x14200 bored systqmp 99873 474823 0 0 3 0x14200 bored systq *88245 209207 0 0 7 0x40014200 softclock 56494 79181 0 0 3 0x40014200 idle0 85052 489434 0 0 3 0x14200 bored smr 1 328519 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 88245 (softclock) thread 0xffff800020a10ed0 (209207) exclusive rwlock netlock r = 0 (0xffffffff82488308) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 mld6_fasttimeo+0x1d sys/netinet6/mld6.c:336 #2 pffasttimo+0x85 sys/kern/uipc_domain.c:292 #3 timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] #3 timeout_run+0xc4 sys/kern/kern_timeout.c:474 #4 softclock_thread+0x16a sys/kern/kern_timeout.c:553 #5 proc_trampoline+0x1c shared rwlock timeout r = 0 (0xffffffff824bef38) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 timeout_run+0xb9 sys/kern/kern_timeout.c:473 #2 softclock_thread+0x16a sys/kern/kern_timeout.c:553 #3 proc_trampoline+0x1c exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8265c400) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 __mp_acquire_count+0x51 sys/kern/kern_lock.c:227 #2 mi_switch+0x392 sys/kern/sched_bsd.c:441 #3 sleep_finish+0x113 sys/kern/kern_synch.c:373 #4 softclock_thread+0x103 sys/kern/kern_timeout.c:548 #5 proc_trampoline+0x1c ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9458 6385K 6385K 78643K 10545 0 0 pcb 13 8K 8K 78643K 13 0 0 rtable 77 2K 2K 78643K 165 0 0 ifaddr 32 9K 9K 78643K 92 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1468 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1181 74K 74K 78643K 1186 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 1K 78643K 2 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 2 0K 0K 78643K 2 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 2 4K 12K 78643K 77 0 0 proc 59 63K 83K 78643K 384 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 in_multi 22 1K 1K 78643K 22 0 0 ether_multi 1 0K 0K 78643K 1 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 24 106K 106K 78643K 24 0 0 exec 0 0K 1K 78643K 199 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 73 12K 12K 78643K 1016 0 0 UVM aobj 2 2K 2K 78643K 2 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 NDP 5 0K 0K 78643K 7 0 0 temp 48 3542K 3606K 78643K 3455 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 4 0 1 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 17 0 15 1 0 1 1 0 8 0 rtentry 112 34 0 4 1 0 1 1 0 8 0 unpcb 120 29 0 19 1 0 1 1 0 8 0 syncache 264 5 0 5 1 1 0 1 0 8 0 tcpcb 544 8 0 5 1 0 1 1 0 8 0 inpcb 280 93 0 87 1 0 1 1 0 8 0 nd6 48 2 0 0 1 0 1 1 0 8 0 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 10 0 0 1 0 1 1 0 8 0 pfstkey 112 10 0 0 1 0 1 1 0 8 0 pfstate 328 10 0 0 1 0 1 1 0 8 0 pfrule 1360 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 256 167 0 2 11 0 11 11 0 8 0 art_table 32 168 0 2 2 0 2 2 0 8 0 art_node 16 33 0 6 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1481 0 79 46 0 46 46 0 8 0 ffsino 272 1481 0 79 94 0 94 94 0 8 0 nchpl 144 1779 0 168 60 0 60 60 0 8 0 uvmvnodes 72 1491 0 0 28 0 28 28 0 8 0 vnodes 208 1491 0 0 79 0 79 79 0 8 0 namei 1024 4618 0 4618 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 4590 0 4590 8 1 7 7 0 8 7 plimitpl 152 15 0 8 1 0 1 1 0 8 0 sigapl 432 285 0 272 2 0 2 2 0 8 0 knotepl 112 39 0 28 1 0 1 1 0 8 0 kqueuepl 104 2 0 0 1 0 1 1 0 8 0 pipepl 112 154 0 141 2 1 1 1 0 8 0 fdescpl 488 286 0 272 3 0 3 3 0 8 0 filepl 152 1419 0 1361 3 0 3 3 0 8 0 lockfpl 104 5 0 4 1 0 1 1 0 8 0 lockfspl 48 3 0 2 1 0 1 1 0 8 0 sessionpl 112 19 0 9 1 0 1 1 0 8 0 pgrppl 48 19 0 9 1 0 1 1 0 8 0 ucredpl 96 232 0 223 1 0 1 1 0 8 0 zombiepl 144 272 0 271 2 1 1 1 0 8 0 processpl 896 301 0 271 4 0 4 4 0 8 0 procpl 632 309 0 271 4 0 4 4 0 8 0 sockpl 384 139 0 121 2 0 2 2 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 74 0 0 10 0 10 10 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 105 0 0 6 0 6 6 0 8 0 bufpl 256 5946 0 1315 290 0 290 290 0 8 0 anonpl 16 23880 0 22040 15 2 13 13 0 124 5 amapchunkpl 152 821 0 758 5 0 5 5 0 158 2 amappl16 192 390 0 345 3 0 3 3 0 8 0 amappl14 176 36 0 31 2 1 1 1 0 8 0 amappl12 160 6 0 5 2 1 1 1 0 8 0 amappl11 152 52 0 37 1 0 1 1 0 8 0 amappl10 144 13 0 9 1 0 1 1 0 8 0 amappl9 136 520 0 514 1 0 1 1 0 8 0 amappl8 128 189 0 179 1 0 1 1 0 8 0 amappl7 120 35 0 31 1 0 1 1 0 8 0 amappl6 112 78 0 69 1 0 1 1 0 8 0 amappl5 104 123 0 109 1 0 1 1 0 8 0 amappl4 96 561 0 533 1 0 1 1 0 8 0 amappl3 88 117 0 111 1 0 1 1 0 8 0 amappl2 80 1070 0 1010 4 1 3 3 0 8 1 amappl1 72 15600 0 15189 25 7 18 20 0 8 8 amappl 80 536 0 508 1 0 1 1 0 84 0 dma4096 4096 1 0 1 1 1 0 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 17 0 17 1 1 0 1 0 8 0 aobjpl 64 1 0 0 1 0 1 1 0 8 0 uaddrrnd 24 286 0 272 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 286 0 272 1 0 1 1 0 8 0 vmmpekpl 168 6526 0 6504 2 0 2 2 0 8 0 vmmpepl 168 35162 0 34235 88 8 80 80 0 357 39 vmsppl 368 285 0 272 2 0 2 2 0 8 0 pdppl 4096 579 0 544 6 0 6 6 0 8 1 pvpl 32 118727 0 114509 117 2 115 115 0 265 80 pmappl 232 285 0 272 1 0 1 1 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 430 0 3 13 0 13 13 0 8 0