panic: Data modified on freelist: word 4 of object 0xffff800000e57600 size 0x104 previous type counters (0x6563 != 0xdeaf4152) Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *228376 75472 0 0x12 0x1 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8259ce31) at panic+0x177 sys/kern/subr_prf.c:198 malloc(104,7f,1) at malloc+0xa85 sys/kern/kern_malloc.c:362 ktrgenio(ffff8000212337a8,4,1,ffff8000006c73c0,fc) at ktrgenio+0x160 dofilewritev(ffff8000212337a8,4,ffff8000212a6ef8,0,ffff8000212a6fe0) at dofilewritev+0x397 sys/kern/sys_generic.c:396 sys_write(ffff8000212337a8,ffff8000212a6f90,ffff8000212a6fe0) at sys_write+0x83 sys/kern/sys_generic.c:295 syscall(ffff8000212a7060) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff8000212a7060) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe5900, count: 7 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: Data modified on freelist: word 4 of object 0xffff800000e57600 size 0x104 previous type counters (0x6563 != 0xdeaf4152) ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8259ce31) at panic+0x177 sys/kern/subr_prf.c:198 malloc(104,7f,1) at malloc+0xa85 sys/kern/kern_malloc.c:362 ktrgenio(ffff8000212337a8,4,1,ffff8000006c73c0,fc) at ktrgenio+0x160 dofilewritev(ffff8000212337a8,4,ffff8000212a6ef8,0,ffff8000212a6fe0) at dofilewritev+0x397 sys/kern/sys_generic.c:396 sys_write(ffff8000212337a8,ffff8000212a6f90,ffff8000212a6fe0) at sys_write+0x83 sys/kern/sys_generic.c:295 syscall(ffff8000212a7060) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff8000212a7060) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe5900, count: -8 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff8000212a6ba0 rbx 0xffffffff8298bb8f cpu_info_full_primary+0x2b8f rdx 0 rcx 0 rax 0xffff8000212337a8 r8 0x101010101010101 r9 0x8080808080808080 r10 0x3dcbb99ee88fe57a r11 0xdd9051780f446d68 r12 0xffffffff8298b990 cpu_info_full_primary+0x2990 r13 0 r14 0 r15 0x1 rip 0xffffffff814c6058 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000212a6b90 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (sshd) pid=228376 stat=onproc flags process=12 proc=1 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800021232d28,0xffff800021232a98 process=0xffff80002129b1f0 user=0xffff8000212a2000, vmspace=0xfffffd806f7a8a18 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 12859 427850 22714 0 3 0x82 piperd syz-executor.6 89630 88923 22714 0 3 0x82 piperd syz-executor.3 31095 153124 22714 0 3 0x82 piperd syz-executor.0 90239 215682 22714 0 3 0x82 piperd syz-executor.1 3217 15592 22714 0 3 0x82 piperd syz-executor.2 10646 6903 22714 0 3 0x82 piperd syz-executor.5 37759 212806 0 0 3 0x14280 nfsidl nfsio 43693 297455 0 0 3 0x14280 nfsidl nfsio 5761 198581 0 0 3 0x14280 nfsidl nfsio 22453 451028 0 0 3 0x14280 nfsidl nfsio 27591 187770 0 0 3 0x14280 nfsidl nfsio 88760 208901 0 0 3 0x14280 nfsidl nfsio 64644 413427 0 0 3 0x14280 nfsidl nfsio 12090 251692 0 0 3 0x14280 nfsidl nfsio 75469 329986 0 0 3 0x14280 nfsidl nfsio 31706 56278 0 0 3 0x14280 nfsidl nfsio 25353 520186 0 0 3 0x14280 nfsidl nfsio 61859 20516 0 0 3 0x14280 nfsidl nfsio 79892 220730 0 0 3 0x14280 nfsidl nfsio 79805 403461 0 0 3 0x14280 nfsidl nfsio 70866 287499 0 0 3 0x14280 nfsidl nfsio 97346 292657 0 0 3 0x14280 nfsidl nfsio 19469 214941 0 0 3 0x14280 nfsidl nfsio 18541 28982 0 0 3 0x14280 nfsidl nfsio 21113 338759 0 0 3 0x14280 nfsidl nfsio 22223 492446 0 0 3 0x14280 nfsidl nfsio 48549 230067 22714 0 3 0x82 piperd syz-executor.7 83453 29060 1 0 3 0x100083 ttyin getty 96446 61076 22714 0 3 0x82 piperd syz-executor.4 85663 182422 0 0 3 0x14200 acct acct 14490 327969 0 0 3 0x14200 bored sosplice 22714 291523 51206 0 3 0x82 thrsleep syz-fuzzer 22714 280059 51206 0 3 0x4000082 nanoslp syz-fuzzer 22714 41521 51206 0 2 0x4000002 syz-fuzzer 22714 301208 51206 0 3 0x4000082 wait syz-fuzzer 22714 341815 51206 0 3 0x4000082 wait syz-fuzzer 22714 338397 51206 0 3 0x4000082 thrsleep syz-fuzzer 22714 487866 51206 0 3 0x4000082 wait syz-fuzzer 22714 195077 51206 0 2 0x4000002 syz-fuzzer 22714 348176 51206 0 3 0x4000082 thrsleep syz-fuzzer 22714 264750 51206 0 3 0x4000082 thrsleep syz-fuzzer 22714 274599 51206 0 3 0x4000082 wait syz-fuzzer 22714 245748 51206 0 3 0x4000082 thrsleep syz-fuzzer 22714 510849 51206 0 3 0x4000082 wait syz-fuzzer 22714 490520 51206 0 3 0x4000082 wait syz-fuzzer 22714 60 51206 0 3 0x4000082 wait syz-fuzzer 22714 4061 51206 0 3 0x4000082 wait syz-fuzzer 51206 16252 75472 0 3 0x10008a sigsusp ksh *75472 228376 53473 0 7 0x13 sshd 53473 512457 1 0 3 0x88 kqread sshd 63924 363537 78024 74 3 0x1100092 bpf pflogd 78024 68817 1 0 3 0x80 netio pflogd 55362 37928 82856 73 3 0x1100090 kqread syslogd 82856 73168 1 0 3 0x100082 netio syslogd 23059 462295 1 0 3 0x100080 kqread resolvd 18873 126209 12583 77 3 0x100092 kqread dhcpleased 45646 230088 12583 77 3 0x100092 kqread dhcpleased 12583 14754 1 0 3 0x80 kqread dhcpleased 870 354931 0 0 3 0x14200 bored smr 5362 377690 0 0 2 0x14200 zerothread 44311 425998 0 0 3 0x14200 aiodoned aiodoned 22080 214207 0 0 3 0x14200 syncer update 78294 184145 0 0 3 0x14200 cleaner cleaner 62322 107838 0 0 3 0x14200 reaper reaper 45815 121196 0 0 3 0x14200 pgdaemon pagedaemon 46998 158133 0 0 3 0x14200 bored viomb 94759 427920 0 0 3 0x40014200 acpi0 acpi0 7631 519909 0 0 7 0x40014200 idle1 4982 359 0 0 3 0x14200 bored softnet 55310 133357 0 0 3 0x14200 bored softnet 91348 318058 0 0 2 0x14200 softnet 43549 450435 0 0 3 0x14200 bored softnet 25597 129701 0 0 3 0x14200 bored systqmp 68952 393555 0 0 3 0x14200 bored systq 77924 77816 0 0 3 0x40014200 bored softclock 80954 319829 0 0 3 0x40014200 idle0 1 243057 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10247 6519K 6926K 78643K 27560 0 pcb 13 18K 20K 78643K 1926 0 rtable 258 24K 25K 78643K 3728 0 ifaddr 176 42K 42K 78643K 1726 0 sysctl 3 1K 1K 78643K 3 0 counters 54 35K 36K 78643K 472 0 ioctlops 0 0K 4K 78643K 4734 0 iov 0 0K 28K 78643K 1164 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1433 90K 90K 78643K 8099 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 185 0 VM map 2 1K 1K 78643K 2 0 sem 12 10K 11K 78643K 16 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 10 33K 89K 78643K 13519 0 sigio 0 0K 0K 78643K 302 0 proc 70 91K 128K 78643K 2460 0 subproc 104 6K 6K 78643K 780 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 427 0 in_multi 92 6K 7K 78643K 889 0 ether_multi 1 0K 0K 78643K 46 0 mrt 1 0K 0K 78643K 82 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 265 1182K 1182K 78643K 265 0 exec 0 0K 3K 78643K 3699 0 tdb 3 0K 0K 78643K 3 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 8 62K 64K 78643K 10 0 UVM amap 335 206K 219K 78643K 74209 0 UVM aobj 134 4K 4K 78643K 144 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 455 0 NDP 14 0K 2K 78643K 299 0 temp 147 4735K 70270K 78643K 92539 0 kqueue 12 18K 26K 78643K 908 0 SYN cache 2 16K 24K 78643K 3 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 22 0 0 1 0 1 1 0 8 0 rtpcb 120 930 0 927 11 9 2 3 0 8 1 rtentry 112 868 0 775 4 0 4 4 0 8 0 unpcb 144 6839 0 6824 84 83 1 10 0 8 0 syncache 296 95 0 95 23 23 0 1 0 8 0 tcpqe 32 116 70 116 7 7 0 1 0 8 0 tcpcb 768 6097 0 6093 210 203 7 22 0 8 6 arp 120 132 0 116 1 0 1 1 0 8 0 inpcb 368 11968 0 11961 196 189 7 17 0 8 6 nd6 48 193 0 171 1 0 1 1 0 8 0 pkpcb 40 12 0 12 3 3 0 1 0 8 0 kcovpl 48 60 0 52 1 0 1 1 0 8 0 ppxss 1256 119 0 119 18 17 1 1 0 8 1 pfstscr 40 102 0 98 3 2 1 1 0 8 0 pffrag 232 26 0 26 6 6 0 1 0 482 0 pffrnode 88 26 0 26 6 6 0 1 0 8 0 pffrent 40 115 0 115 7 7 0 1 0 8 0 pfosfp 40 1457 0 1454 6 5 1 5 0 8 0 pfosfpen 112 1457 0 1453 22 21 1 21 0 8 0 pfrktable 1344 426 0 411 5 3 2 2 0 8 0 pfanchor 1280 594 97 82 43 0 43 43 0 8 0 pftag 88 152 0 149 2 1 1 1 0 8 0 pfqueue 264 8 0 8 3 3 0 1 0 8 0 pfstitem 24 57 0 47 1 0 1 1 0 8 0 pfstkey 120 225 0 220 1 0 1 1 0 8 0 pfstate 336 133 0 127 3 2 1 3 0 8 0 pfrule 1360 668 0 616 10 5 5 5 0 8 0 rttmr 136 29 0 29 8 8 0 1 0 8 0 art_heap8 4096 3 0 2 3 2 1 2 0 8 0 art_heap4 256 3587 0 3175 59 30 29 31 0 8 0 art_table 32 3590 0 3177 4 0 4 4 0 8 0 art_node 16 820 0 739 1 0 1 1 0 8 0 sysvmsgpl 40 52 0 12 1 0 1 1 0 8 0 semapl 112 10 0 0 1 0 1 1 0 8 0 shmpl 112 141 0 13 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 19347 0 17878 93 0 93 93 0 8 0 ffsino 272 19347 0 17878 99 0 99 99 0 8 0 nchpl 144 36975 0 36477 63 39 24 63 0 8 0 rtmask 32 2 0 2 1 1 0 1 0 8 0 uvmvnodes 80 6062 0 0 124 0 124 124 0 8 0 vnodes 216 6062 0 0 337 0 337 337 0 8 0 namei 1024 162819 0 162819 7 6 1 2 0 8 1 percpumem 16 248 0 209 1 0 1 1 0 8 0 vcpupl 2048 43 0 0 6 0 6 6 0 8 0 vmpool 568 49 0 6 4 0 4 4 0 8 0 pfiaddrpl 120 120 0 91 2 1 1 1 0 8 0 kstatmem 264 342 0 314 6 3 3 3 0 8 0 scxspl 216 114786 0 114786 18 17 1 8 0 8 1 plimitpl 152 1706 0 1690 1 0 1 1 0 8 0 sigapl 424 13793 0 13731 11 3 8 8 0 8 0 futexpl 64 134205 0 134205 7 6 1 1 0 8 1 knotepl 120 1219 0 0 24 1 23 23 0 8 0 kqueuepl 216 2721 0 2713 58 55 3 8 0 8 2 pipepl 320 2653 0 2625 70 65 5 8 0 8 2 fdescpl 496 13714 0 13691 7 3 4 5 0 8 0 filepl 152 117422 0 117183 159 140 19 24 0 8 8 lockfpl 104 3022 0 3020 10 9 1 4 0 8 0 lockfspl 48 881 0 879 1 0 1 1 0 8 0 sessionpl 144 79 0 62 1 0 1 1 0 8 0 pgrppl 48 974 0 957 1 0 1 1 0 8 0 ucredpl 104 12439 0 12426 1 0 1 1 0 8 0 zombiepl 144 13731 0 13731 2 1 1 1 0 8 1 processpl 1064 13793 0 13731 5 0 5 5 0 8 0 procpl 672 34473 0 34396 25 16 9 10 0 8 1 srpgc 96 84 0 84 13 13 0 1 0 8 0 sosppl 168 84 0 84 3 3 0 1 0 8 0 sockpl 488 19775 0 19750 397 385 12 34 0 8 8 mcl64k 65536 12 0 0 2 0 2 2 0 8 0 mcl16k 16384 6 0 0 1 0 1 1 0 8 0 mcl12k 12288 8 0 0 1 0 1 1 0 8 0 mcl9k 9216 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 6 0 0 1 0 1 1 0 8 0 mcl4k 4096 27 0 0 4 0 4 4 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 374 0 0 40 7 33 40 0 8 0 mtagpl 96 779 0 0 13 0 13 13 0 8 0 mbufpl 256 2080 0 0 88 0 88 88 0 8 0 bufpl 288 24536 0 18197 454 0 454 454 0 8 0 anonpl 24 2622882 0 2606530 307 185 122 148 0 186 0 amapchunkpl 152 217008 0 216348 72 38 34 41 0 158 0 amappl16 200 40736 0 40184 197 165 32 44 0 8 0 amappl15 192 5153 0 5150 1 0 1 1 0 8 0 amappl14 184 4812 0 4799 1 0 1 1 0 8 0 amappl13 176 586 0 585 1 0 1 1 0 8 0 amappl12 168 1756 0 1748 1 0 1 1 0 8 0 amappl11 160 1520 0 1499 3 2 1 2 0 8 0 amappl10 152 519 0 512 1 0 1 1 0 8 0 amappl9 144 2380 0 2379 1 0 1 1 0 8 0 amappl8 136 2498 0 2376 5 0 5 5 0 8 0 amappl7 128 1046 0 1022 1 0 1 1 0 8 0 amappl6 120 2411 0 2389 2 1 1 2 0 8 0 amappl5 112 8037 0 8024 1 0 1 1 0 8 0 amappl4 104 8186 0 8145 2 0 2 2 0 8 0 amappl3 96 40085 0 40042 2 0 2 2 0 8 0 amappl2 88 2075 0 2013 3 1 2 3 0 8 0 amappl1 80 335968 0 335297 23 5 18 23 0 8 0 amappl 88 72604 0 72425 8 3 5 6 0 92 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 72 143 0 10 3 0 3 3 0 8 0 uaddrrnd 24 13763 0 13697 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 13763 0 13697 1 0 1 1 0 8 0 vmmpekpl 168 99057 0 98972 6 1 5 5 0 8 0 vmmpepl 168 1336166 0 1333679 373 226 147 165 0 357 1 vmsppl 368 13762 0 13697 8 1 7 7 0 8 0 rwobjpl 56 322050 0 314123 148 34 114 116 0 8 0 pdppl 4096 27533 0 27437 777 667 110 114 0 8 14 pvpl 32 5229108 0 5207964 619 417 202 270 0 265 0 pmappl 248 13762 0 13697 6 1 5 5 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1875 0 928 28 0 28 28 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:437 panic(ffffffff8259ce31) at panic+0x177 sys/kern/subr_prf.c:198 malloc(104,7f,1) at malloc+0xa85 sys/kern/kern_malloc.c:362 ktrgenio(ffff8000212337a8,4,1,ffff8000006c73c0,fc) at ktrgenio+0x160 dofilewritev(ffff8000212337a8,4,ffff8000212a6ef8,0,ffff8000212a6fe0) at dofilewritev+0x397 sys/kern/sys_generic.c:396 sys_write(ffff8000212337a8,ffff8000212a6f90,ffff8000212a6fe0) at sys_write+0x83 sys/kern/sys_generic.c:295 syscall(ffff8000212a7060) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff8000212a7060) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe5900, count: -8 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020dd8ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 acpicpu_idle() at acpicpu_idle+0x312 sys/dev/acpi/acpicpu.c:1206 sched_idle(ffff800020dd8ff0) at sched_idle+0x417 sys/kern/kern_sched.c:175 end trace frame: 0x0, count: 10 ddb{1}> trace x86_ipi_db(ffff800020dd8ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 acpicpu_idle() at acpicpu_idle+0x312 sys/dev/acpi/acpicpu.c:1206 sched_idle(ffff800020dd8ff0) at sched_idle+0x417 sys/kern/kern_sched.c:175 end trace frame: 0x0, count: -5