panic: Data modified on freelist: word 4 of object 0xffff80000158ddc0 size 0x28 previous type free (0x0 != 0xdeafbead) Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *103482 69731 0 0x2 0x1 0 syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8333ecfe) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(28,7f,1) at malloc+0xdb6 sys/kern/kern_malloc.c:355 ktrsyscall(ffff80002a7762a0,b,20,ffff80002a8a9000) at ktrsyscall+0x199 sys/kern/kern_ktrace.c:174 syscall(ffff80002a8a9000) at syscall+0x2bc mi_syscall sys/sys/syscall_mi.h:154 [inline] syscall(ffff80002a8a9000) at syscall+0x2bc sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7dfe85694b20, count: 9 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: Data modified on freelist: word 4 of object 0xffff80000158ddc0 size 0x28 previous type free (0x0 != 0xdeafbead) ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8333ecfe) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(28,7f,1) at malloc+0xdb6 sys/kern/kern_malloc.c:355 ktrsyscall(ffff80002a7762a0,b,20,ffff80002a8a9000) at ktrsyscall+0x199 sys/kern/kern_ktrace.c:174 syscall(ffff80002a8a9000) at syscall+0x2bc mi_syscall sys/sys/syscall_mi.h:154 [inline] syscall(ffff80002a8a9000) at syscall+0x2bc sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7dfe85694b20, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002a8a8cd0 rbx 0xffff80000158ddc0 rdx 0 rcx 0 rax 0xffff80002a7762a0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xf9ff2e0484c4469a r11 0x9e5ad5bfccc07d5a r12 0 r13 0xffffffff839b32c0 kmemstats+0x1fc0 r14 0 r15 0x1 rip 0xffffffff81f6d465 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a8a8cc0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (syz-executor) tid=103482 pid=69731 tcnt=1 stat=onproc flags process=2 proc=1 runpri=76, usrpri=76, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a776538,0xffff80002a776a78 process=0xffff80002a7ded10 user=0xffff80002a8a4000, vmspace=0xfffffd806f5bab88 estcpu=26, cpticks=5, pctcpu=0.0, user=0, sys=5, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 68140 465092 17159 0 2 0 syz-executor 24749 367766 98329 0 2 0 syz-executor 24749 171968 98329 0 3 0x4000080 ttyopn syz-executor 24749 305206 98329 0 3 0x4000080 fsleep syz-executor 24749 229986 98329 0 3 0x4000080 fsleep syz-executor 70987 284180 64346 0 2 0 syz-executor 70987 453760 64346 0 3 0x4000080 fsleep syz-executor 70987 132102 64346 0 3 0x4000080 fsleep syz-executor 70987 97014 64346 0 3 0x4000080 fsleep syz-executor 70987 15344 64346 0 3 0x4000080 fsleep syz-executor 89636 456924 29715 0 3 0x80 nanoslp syz-executor 89636 455504 29715 0 3 0x4000080 kqread syz-executor 89636 127241 29715 0 3 0x4000080 fsleep syz-executor 89636 306699 29715 0 3 0x4000080 fsleep syz-executor 89636 403853 29715 0 3 0x4000080 fsleep syz-executor 63520 136781 24660 0 2 0 syz-executor 63520 484827 24660 0 3 0x4000080 fsleep syz-executor 63520 185061 24660 0 3 0x4000080 fsleep syz-executor 63520 124254 24660 0 3 0x4000080 fsleep syz-executor 25235 34343 43749 0 2 0x100002 arp 43749 475950 10708 0 3 0x10008a sigsusp sh 65404 60769 44570 0 3 0 kmmaplk syz-executor 65404 360296 44570 0 2 0x4000000 syz-executor 65404 414731 44570 0 3 0x4000080 fsleep syz-executor 10708 207509 47019 0 3 0x82 wait syz-executor 44570 211392 47019 0 2 0x3 syz-executor *69731 103482 47019 0 7 0x3 syz-executor 98329 420756 47019 0 2 0x3 syz-executor 24660 291905 47019 0 2 0x3 syz-executor 17159 201116 47019 0 3 0x82 nanoslp syz-executor 64346 256353 47019 0 2 0x3 syz-executor 29715 370975 47019 0 2 0x3 syz-executor 47019 112856 69894 0 2 0x3 syz-executor 69894 270494 30549 0 3 0x10008a sigsusp ksh 30549 45635 81607 0 3 0x98 kqread sshd-session 81607 109027 68029 0 3 0x92 kqread sshd-session 90047 412909 1 0 3 0x100083 ttyin getty 68029 508234 1 0 3 0x88 kqread sshd 15537 172175 72335 73 3 0x1100090 kqread syslogd 72335 226742 1 0 3 0x100082 sbwait syslogd 23366 288533 1 0 3 0x100080 kqread resolvd 90766 303798 84919 77 3 0x100092 kqread dhcpleased 98797 253233 84919 77 3 0x100092 kqread dhcpleased 84919 285199 1 0 3 0x80 kqread dhcpleased 82952 474603 0 0 3 0x14200 bored smr 86674 501181 0 0 2 0x14200 zerothread 2507 326942 0 0 3 0x14200 aiodoned aiodoned 68377 505103 0 0 3 0x14200 syncer update 40089 109184 0 0 3 0x14200 cleaner cleaner 3155 482029 0 0 3 0x14200 kmmaplk reaper 1657 261811 0 0 3 0x14200 pgdaemon pagedaemon 38966 317735 0 0 3 0x14200 bored viomb 70161 185882 0 0 3 0x40014200 acpi0 acpi0 75563 451429 0 0 3 0x14200 bored softnet0 93029 432419 0 0 3 0x14200 bored systqmp 48151 349620 0 0 3 0x14200 bored systq 76415 64549 0 0 3 0x40014200 tmoslp softclock 94356 303147 0 0 3 0x40014200 idle0 1 197054 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 11041 12233K 12323K 166960K 12286 0 pcb 19 12K 12K 166960K 51 0 rtable 217 7K 7K 166960K 466 0 pf 30 12K 13K 166960K 42 0 ifaddr 40 7K 7K 166960K 60 0 ifgroup 50 2K 2K 166960K 72 0 sysctl 3 1K 9K 166960K 8 0 counters 33 17K 18K 166960K 39 0 ioctlops 0 0K 4K 166960K 81 0 iov 0 0K 12K 166960K 7 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1338 84K 85K 166960K 1476 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 4 0 VM map 2 1K 1K 166960K 2 0 sem 4 0K 0K 166960K 4 0 dirhash 12 2K 2K 166960K 15 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 97K 166960K 289 0 sigio 0 0K 0K 166960K 4 0 proc 60 59K 124K 166960K 561 0 subproc 72 4K 4K 166960K 99 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 11 0 in_multi 89 6K 7K 166960K 130 0 ether_multi 1 0K 0K 166960K 2 0 mrt 1 0K 0K 166960K 1 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 55 254K 254K 166960K 55 0 exec 0 0K 1K 166960K 402 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 2 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 241 153K 159K 166960K 4250 0 UVM aobj 9 6K 6K 166960K 9 0 pinsyscall 40 80K 96K 166960K 1426 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 3 0 NDP 11 0K 2K 166960K 36 0 temp 40 8659K 8727K 166960K 11178 0 kqueue 14 22K 26K 166960K 38 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 57 0 51 1 0 1 1 0 8 0 rtentry 136 139 0 46 4 0 4 4 0 8 0 unpcb 144 112 0 96 1 0 1 1 0 8 0 syncache 336 3 0 3 1 1 0 1 0 8 0 tcpcb 736 37 0 33 1 0 1 1 0 8 0 arp 96 24 0 6 1 0 1 1 0 8 0 ipq 40 1 0 0 1 0 1 1 0 8 0 ipqe 40 2 0 0 1 0 1 1 0 8 0 inpcb 328 155 0 145 2 0 2 2 0 8 1 nd6 112 30 0 9 1 0 1 1 0 8 0 pkpcb 40 2 0 2 2 1 1 1 0 8 1 kcovpl 48 11 0 3 1 0 1 1 0 8 0 ppxss 1072 1 0 1 1 0 1 1 0 8 1 pppxif 1384 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 256 582 0 179 29 0 29 29 0 8 1 art_table 40 583 0 179 5 0 5 5 0 8 0 art_node 32 139 0 55 1 0 1 1 0 8 0 semapl 112 2 0 0 1 0 1 1 0 8 0 shmpl 112 5 0 0 1 0 1 1 0 8 0 dirhash 1024 19 0 2 3 0 3 3 0 8 0 dino2pl 256 1768 0 263 95 0 95 95 0 8 0 ffsino 256 1768 0 263 95 0 95 95 0 8 0 nchpl 144 2116 0 417 63 0 63 63 0 8 0 vnodes 216 1928 0 0 108 0 108 108 0 8 0 namei 1024 6572 0 6571 2 1 1 2 0 8 0 vcpupl 3904 1 0 0 1 0 1 1 0 8 0 vmpool 808 1 0 0 1 0 1 1 0 8 0 kstatmem 264 32 0 10 2 0 2 2 0 8 0 scsiplug 72 1 0 1 1 0 1 1 0 8 1 scxspl 216 6840 0 6840 4 2 2 3 1 8 2 plimitpl 152 106 0 90 1 0 1 1 0 8 0 sigapl 424 569 0 525 6 1 5 6 0 8 0 knotepl 120 7294 0 7245 17 8 9 10 0 8 7 kqueuepl 184 48 0 37 1 0 1 1 0 8 0 pipepl 304 130 0 103 3 0 3 3 0 8 0 fdescpl 448 556 0 526 5 1 4 5 0 8 0 filepl 120 2215 0 1995 9 0 9 9 0 8 1 lockfpl 104 37 0 32 1 0 1 1 0 8 0 lockfspl 48 18 0 14 1 0 1 1 0 8 0 sessionpl 144 24 0 16 1 0 1 1 0 8 0 pgrppl 48 36 0 20 1 0 1 1 0 8 0 ucredpl 104 215 0 204 1 0 1 1 0 8 0 zombiepl 144 621 0 620 2 1 1 1 0 8 0 processpl 1152 569 0 525 4 0 4 4 0 8 0 procpl 664 820 0 757 6 0 6 6 0 8 0 sosppl 176 2 0 2 1 1 0 1 0 8 0 sockpl 552 331 0 299 4 0 4 4 0 8 1 mcl64k 65536 4 0 4 2 1 1 1 0 8 1 mcl8k 8192 5 0 5 2 1 1 1 0 8 1 mcl4k 4096 2591 0 2540 14 7 7 14 0 8 0 mcl2k 2048 427 0 424 3 2 1 3 0 8 0 mtagpl 96 8 0 5 2 1 1 1 0 8 0 mbufpl 256 5335 0 5142 13 0 13 13 0 8 0 bufpl 280 2614 0 126 178 0 178 178 0 8 0 anonpl 24 112426 0 109177 35 3 32 32 0 187 10 amapchunkpl 152 12390 0 11898 23 0 23 23 0 158 1 amappl16 200 2057 0 2033 6 3 3 5 0 8 0 amappl15 192 6 0 6 1 1 0 1 0 8 0 amappl14 184 17 0 17 1 1 0 1 0 8 0 amappl13 176 440 0 438 1 0 1 1 0 8 0 amappl12 168 932 0 892 2 0 2 2 0 8 0 amappl11 160 7 0 7 1 1 0 1 0 8 0 amappl10 152 44 0 34 1 0 1 1 0 8 0 amappl9 144 252 0 252 1 1 0 1 0 8 0 amappl8 136 22 0 21 1 0 1 1 0 8 0 amappl7 128 90 0 89 1 0 1 1 0 8 0 amappl6 120 313 0 300 1 0 1 1 0 8 0 amappl5 112 65 0 58 1 0 1 1 0 8 0 amappl4 104 385 0 359 1 0 1 1 0 8 0 amappl3 96 2064 0 1970 3 0 3 3 0 8 0 amappl2 88 663 0 590 2 0 2 2 0 8 0 amappl1 80 9551 0 8986 13 1 12 13 0 8 0 amappl 88 3503 0 3338 5 0 5 5 0 92 0 uvmvnodes 80 97 0 0 2 0 2 2 0 8 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 8 0 0 1 0 1 1 0 8 0 uaddrrnd 24 556 0 526 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 556 0 526 1 0 1 1 0 8 0 vmmpekpl 168 6204 0 6167 2 0 2 2 0 8 0 vmmpepl 168 43153 0 41326 83 0 83 83 0 357 0 vmsppl 368 555 0 525 4 1 3 4 0 8 0 rwobjpl 40 15087 0 14092 12 1 11 11 0 8 0 pdppl 4096 1120 0 1051 101 32 69 82 0 8 0 pvpl 32 267072 0 258275 97 4 93 93 0 265 18 pmappl 216 556 0 525 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 375 0 49 11 0 11 11 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(ffffffff8333ecfe) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(28,7f,1) at malloc+0xdb6 sys/kern/kern_malloc.c:355 ktrsyscall(ffff80002a7762a0,b,20,ffff80002a8a9000) at ktrsyscall+0x199 sys/kern/kern_ktrace.c:174 syscall(ffff80002a8a9000) at syscall+0x2bc mi_syscall sys/sys/syscall_mi.h:154 [inline] syscall(ffff80002a8a9000) at syscall+0x2bc sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7dfe85694b20, count: -6 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8333ecfe) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(28,7f,1) at malloc+0xdb6 sys/kern/kern_malloc.c:355 ktrsyscall(ffff80002a7762a0,b,20,ffff80002a8a9000) at ktrsyscall+0x199 sys/kern/kern_ktrace.c:174 syscall(ffff80002a8a9000) at syscall+0x2bc mi_syscall sys/sys/syscall_mi.h:154 [inline] syscall(ffff80002a8a9000) at syscall+0x2bc sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7dfe85694b20, count: -6