panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806d6d7700+16 0x0!=0x9adedf68c7e57354 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 31780 89336 0 0x2 0x4000480 1 syz-execprog * 48118 15226 0 0x14000 0x40000200 0K softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ffeaf) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff8290d590) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff8290d590) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff8290d590,2) 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(ffff800000676f80,83,0) 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(ffffffff828ac170) at pffasttimo+0x85 sys/kern/uipc_domain.c:292 timeout_run(ffffffff828ac170) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:184 [inline] timeout_run(ffffffff828ac170) at timeout_run+0xc4 sys/kern/kern_timeout.c:490 softclock_thread(ffff800020d88ea0) at softclock_thread+0x16a sys/kern/kern_timeout.c:580 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 0xfffffd806d6d7700+16 0x0!=0x9adedf68c7e57354 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ffeaf) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff8290d590) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff8290d590) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff8290d590,2) 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(ffff800000676f80,83,0) 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(ffffffff828ac170) at pffasttimo+0x85 sys/kern/uipc_domain.c:292 timeout_run(ffffffff828ac170) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:184 [inline] timeout_run(ffffffff828ac170) at timeout_run+0xc4 sys/kern/kern_timeout.c:490 softclock_thread(ffff800020d88ea0) at softclock_thread+0x16a sys/kern/kern_timeout.c:580 end trace frame: 0x0, count: -10 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020d96e20 rbx 0xffff800020d96ed0 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffffffff81d7bbff kprintf+0x16f r9 0x1 r10 0x2 r11 0x6ea67537befdcb0a r12 0x3000000008 r13 0xffff800020d96e30 r14 0x100 r15 0x1 rip 0xffffffff81e2db58 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020d96e10 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=48118 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020d89380,0xffff800020d884f0 process=0xffff800020d8b338 user=0xffff800020d92000, vmspace=0xffffffff82903bb0 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 89120 22101 89336 0 2 0x482 syz-executor.0 89336 136171 18711 0 3 0x82 kqread syz-execprog 89336 8447 18711 0 2 0x4000482 syz-execprog 89336 169370 18711 0 3 0x4000082 thrsleep syz-execprog 89336 200215 18711 0 3 0x4000082 thrsleep syz-execprog 89336 164638 18711 0 3 0x4000082 thrsleep syz-execprog 89336 424151 18711 0 3 0x4000082 thrsleep syz-execprog 89336 389015 18711 0 3 0x4000082 thrsleep syz-execprog 89336 31780 18711 0 7 0x4000482 syz-execprog 89336 486872 18711 0 3 0x4000082 thrsleep syz-execprog 18711 359185 45370 0 3 0x10008a pause ksh 45370 313792 51685 0 3 0x92 select sshd 34134 20085 1 0 3 0x100083 ttyin getty 51685 391370 1 0 3 0x80 select sshd 95682 512328 41802 74 3 0x100092 bpf pflogd 41802 348958 1 0 3 0x80 netio pflogd 79672 34788 56177 73 3 0x100090 kqread syslogd 56177 476598 1 0 3 0x100082 netio syslogd 56253 189821 1 77 3 0x100090 poll dhclient 72638 491326 1 0 3 0x80 poll dhclient 76655 28937 0 0 3 0x14200 bored smr 44653 318006 0 0 3 0x14200 pgzero zerothread 91467 429211 0 0 3 0x14200 aiodoned aiodoned 44638 91360 0 0 3 0x14200 syncer update 74522 68086 0 0 3 0x14200 cleaner cleaner 88740 69490 0 0 3 0x14200 reaper reaper 52545 446865 0 0 3 0x14200 pgdaemon pagedaemon 20372 301008 0 0 3 0x14200 bored crynlk 22109 310596 0 0 3 0x14200 bored crypto 70429 276917 0 0 3 0x40014200 acpi0 acpi0 14481 50555 0 0 3 0x40014200 idle1 17627 245706 0 0 3 0x14200 bored softnet 90044 228546 0 0 3 0x14200 bored systqmp 79303 296230 0 0 3 0x14200 bored systq *15226 48118 0 0 7 0x40014200 softclock 21986 358208 0 0 3 0x40014200 idle0 1 174183 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 15226 (softclock) thread 0xffff800020d88ea0 (48118) exclusive rwlock netlock r = 0 (0xffffffff82757548) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #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:184 [inline] #3 timeout_run+0xc4 sys/kern/kern_timeout.c:490 #4 softclock_thread+0x16a sys/kern/kern_timeout.c:580 #5 proc_trampoline+0x1c shared rwlock timeout r = 0 (0xffffffff82778cc8) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 timeout_run+0xb9 sys/kern/kern_timeout.c:489 #2 softclock_thread+0x16a sys/kern/kern_timeout.c:580 #3 proc_trampoline+0x1c exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8292aa38) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 __mp_acquire_count+0x51 sys/kern/kern_lock.c:227 #2 mi_switch+0x392 sys/kern/sched_bsd.c:435 #3 sleep_finish+0x113 sys/kern/kern_synch.c:418 #4 softclock_thread+0x103 sys/kern/kern_timeout.c:575 #5 proc_trampoline+0x1c ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9467 6396K 6396K 78643K 10560 0 pcb 13 8K 8K 78643K 13 0 rtable 83 2K 2K 78643K 163 0 ifaddr 37 9K 9K 78643K 270 0 counters 41 33K 33K 78643K 41 0 ioctlops 0 0K 4K 78643K 1468 0 mount 1 1K 1K 78643K 1 0 vnodes 1183 74K 75K 78643K 1188 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 1K 78643K 2 0 VM map 2 1K 1K 78643K 2 0 sem 2 0K 0K 78643K 2 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1824 197K 290K 78643K 13058 0 file desc 2 4K 12K 78643K 249 0 proc 59 63K 83K 78643K 398 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 22 1K 1K 78643K 22 0 ether_multi 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 19 95K 95K 78643K 19 0 exec 0 0K 1K 78643K 197 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 73 12K 12K 78643K 1175 0 UVM aobj 2 2K 2K 78643K 2 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 5 0K 0K 78643K 7 0 temp 29 3853K 3917K 78643K 2330 0 kqueue 3 4K 4K 78643K 3 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 4 0 0 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 1 1 0 1 1 0 8 0 unpcb 120 29 0 19 1 0 1 1 0 8 0 syncache 264 5 0 5 2 2 0 1 0 8 0 tcpcb 544 8 0 5 1 0 1 1 0 8 0 inpcb 296 265 0 259 1 0 1 1 0 8 0 nd6 48 3 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 11 0 7 1 0 1 1 0 8 0 pfstkey 112 11 0 7 1 0 1 1 0 8 0 pfstate 328 11 0 7 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 256 144 0 0 9 0 9 9 0 8 0 art_table 32 145 0 0 2 0 2 2 0 8 0 art_node 16 33 0 3 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1655 0 253 88 0 88 88 0 8 0 ffsino 272 1655 0 253 94 0 94 94 0 8 0 nchpl 144 2105 0 501 60 0 60 60 0 8 0 uvmvnodes 72 1665 0 0 31 0 31 31 0 8 0 vnodes 208 1665 0 0 88 0 88 88 0 8 0 namei 1024 5154 0 5154 2 1 1 1 0 8 1 percpumem 16 31 0 0 1 0 1 1 0 8 0 scxspl 192 6016 0 6016 11 10 1 7 0 8 1 plimitpl 152 15 0 8 1 0 1 1 0 8 0 sigapl 424 472 0 443 4 0 4 4 0 8 0 knotepl 112 47 0 36 1 0 1 1 0 8 0 kqueuepl 144 2 0 0 1 0 1 1 0 8 0 pipepl 304 77 0 70 2 1 1 1 0 8 0 fdescpl 496 457 0 443 3 0 3 3 0 8 0 filepl 152 1578 0 1520 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 62 0 53 1 0 1 1 0 8 0 zombiepl 144 443 0 442 2 1 1 1 0 8 0 processpl 984 472 0 442 5 0 5 5 0 8 1 procpl 624 480 0 442 4 0 4 4 0 8 1 sockpl 400 311 0 293 2 0 2 2 0 8 0 mcl4k 4096 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 56 0 0 7 0 7 7 0 8 0 mtagpl 96 1 0 0 1 0 1 1 0 8 0 mbufpl 256 99 0 0 6 0 6 6 0 8 0 mbufpl: pool(0xffffffff8290d590:mbufpl): free list modified: page 0xfffffd8077699000; item ordinal 10; addr 0xfffffd8077699b00 (p 0xfffffd806e2ec000); offset 0x0=0x0 pool(mbufpl): free list modified: page 0xfffffd8077699000; item ordinal 10; addr 0xfffffd8077699b00 (p 0xfffffd806e2ec000); offset 0x0=0x0 mbufpl: pool(0xffffffff8290d590:mbufpl): page inconsistency: page 0xfffffd8077699000; item ordinal 11; addr 0xad1b3ce48f6aed31 bufpl 280 3280 0 132 225 0 225 225 0 8 0 anonpl 16 28148 0 26330 13 1 12 12 0 124 3 amapchunkpl 152 1044 0 978 4 0 4 4 0 158 1 amappl16 192 855 0 810 3 0 3 3 0 8 0 amappl15 184 2 0 2 2 1 1 1 0 8 1 amappl14 176 267 0 261 1 0 1 1 0 8 0 amappl13 168 23 0 21 2 1 1 1 0 8 0 amappl11 152 284 0 268 1 0 1 1 0 8 0 amappl10 144 18 0 13 1 0 1 1 0 8 0 amappl9 136 235 0 234 1 0 1 1 0 8 0 amappl8 128 269 0 261 1 0 1 1 0 8 0 amappl7 120 115 0 102 1 0 1 1 0 8 0 amappl6 112 253 0 250 2 1 1 1 0 8 0 amappl5 104 121 0 107 1 0 1 1 0 8 0 amappl4 96 728 0 702 1 0 1 1 0 8 0 amappl3 88 105 0 99 1 0 1 1 0 8 0 amappl2 80 1374 0 1315 2 0 2 2 0 8 0 amappl1 72 17378 0 16954 23 5 18 18 0 8 8 amappl 80 704 0 676 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 18 0 17 1 0 1 1 0 8 0 aobjpl 64 1 0 0 1 0 1 1 0 8 0 uaddrrnd 24 457 0 443 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 457 0 443 1 0 1 1 0 8 0 vmmpekpl 168 6593 0 6568 2 0 2 2 0 8 0 vmmpepl 168 42582 0 41642 81 9 72 72 0 357 29 vmsppl 368 456 0 443 2 0 2 2 0 8 0 pdppl 4096 921 0 886 6 0 6 6 0 8 1 pvpl 32 138919 0 134719 108 4 104 104 0 265 69 pmappl 232 456 0 443 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 230 0 4 7 0 7 7 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ffeaf) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff8290d590) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff8290d590) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff8290d590,2) 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(ffff800000676f80,83,0) 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(ffffffff828ac170) at pffasttimo+0x85 sys/kern/uipc_domain.c:292 timeout_run(ffffffff828ac170) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:184 [inline] timeout_run(ffffffff828ac170) at timeout_run+0xc4 sys/kern/kern_timeout.c:490 softclock_thread(ffff800020d88ea0) at softclock_thread+0x16a sys/kern/kern_timeout.c:580 end trace frame: 0x0, count: -10 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020d70ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:352 x86_ipi_handler() at x86_ipi_handler+0xc6 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff8292a830) at __mp_lock+0x127 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff8292a830) at __mp_lock+0x127 sys/kern/kern_lock.c:147 __mp_acquire_count(ffffffff8292a830,1) at __mp_acquire_count+0x51 sys/kern/kern_lock.c:227 mi_switch() at mi_switch+0x392 sys/kern/sched_bsd.c:435 sleep_finish(ffff800020e9b1d0,1) at sleep_finish+0x113 sys/kern/kern_synch.c:418 sleep_finish_all(ffff800020e9b1d0,1) at sleep_finish_all+0x32 sleep_finish_timeout sys/kern/kern_synch.c:447 [inline] sleep_finish_all(ffff800020e9b1d0,1) at sleep_finish_all+0x32 sys/kern/kern_synch.c:393 tsleep(ffffffff827b12a0,120,ffffffff823ef60b,2) at tsleep+0x1cc sys/kern/kern_synch.c:155 sys_nanosleep(ffff800020ddc758,ffff800020e9b300,ffff800020e9b350) at sys_nanosleep+0x205 sys/kern/kern_time.c:297 syscall(ffff800020e9b3d0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e9b3d0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xc000151e40, count: 3 ddb{1}> trace x86_ipi_db(ffff800020d70ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:352 x86_ipi_handler() at x86_ipi_handler+0xc6 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff8292a830) at __mp_lock+0x127 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff8292a830) at __mp_lock+0x127 sys/kern/kern_lock.c:147 __mp_acquire_count(ffffffff8292a830,1) at __mp_acquire_count+0x51 sys/kern/kern_lock.c:227 mi_switch() at mi_switch+0x392 sys/kern/sched_bsd.c:435 sleep_finish(ffff800020e9b1d0,1) at sleep_finish+0x113 sys/kern/kern_synch.c:418 sleep_finish_all(ffff800020e9b1d0,1) at sleep_finish_all+0x32 sleep_finish_timeout sys/kern/kern_synch.c:447 [inline] sleep_finish_all(ffff800020e9b1d0,1) at sleep_finish_all+0x32 sys/kern/kern_synch.c:393 tsleep(ffffffff827b12a0,120,ffffffff823ef60b,2) at tsleep+0x1cc sys/kern/kern_synch.c:155 sys_nanosleep(ffff800020ddc758,ffff800020e9b300,ffff800020e9b350) at sys_nanosleep+0x205 sys/kern/kern_time.c:297 syscall(ffff800020e9b3d0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e9b3d0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xc000151e40, count: -12