panic: Data modified on freelist: word 4 of object 0xffff800000cd6c00 size 0x168 previous type free (0x6563 != 0xdead4110) Stopped at db_enter+0x1c: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 61994 143 0 0 0x4000000 0 syz-executor.4 db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8278176c) at panic+0x165 sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:357 bpfopen(31700,63,2000,ffff80002170d2c0) at bpfopen+0xc0 sys/net/bpf.c:391 spec_open_clone(ffff80002659b658) at spec_open_clone+0x208 spec_open(ffff80002659b658) at spec_open+0x401 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd806eea48a0,63,fffffd807f7d7618,ffff80002170d2c0) at VOP_OPEN+0x70 sys/kern/vfs_vops.c:138 vn_open(ffff80002659b8a8,63,0) at vn_open+0x452 sys/kern/vfs_vnops.c:177 doopenat(ffff80002170d2c0,ffffff9c,20000040,462,0,ffff80002659ba80) at doopenat+0x26e sys/kern/vfs_syscalls.c:1126 syscall(ffff80002659bb00) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xbb31581f790, count: 4 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 0xffff800000cd6c00 size 0x168 previous type free (0x6563 != 0xdead4110) ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8278176c) at panic+0x165 sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:357 bpfopen(31700,63,2000,ffff80002170d2c0) at bpfopen+0xc0 sys/net/bpf.c:391 spec_open_clone(ffff80002659b658) at spec_open_clone+0x208 spec_open(ffff80002659b658) at spec_open+0x401 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd806eea48a0,63,fffffd807f7d7618,ffff80002170d2c0) at VOP_OPEN+0x70 sys/kern/vfs_vops.c:138 vn_open(ffff80002659b8a8,63,0) at vn_open+0x452 sys/kern/vfs_vnops.c:177 doopenat(ffff80002170d2c0,ffffff9c,20000040,462,0,ffff80002659ba80) at doopenat+0x26e sys/kern/vfs_syscalls.c:1126 syscall(ffff80002659bb00) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xbb31581f790, count: -11 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002659b370 rbx 0xffff800000cd6c00 rdx 0 rcx 0 rax 0xffff80002170d2c0 r8 0x101010101010101 r9 0x8080808080808080 r10 0x9e279278fca51cb1 r11 0xed8a168448b00c11 r12 0 r13 0x51 r14 0 r15 0x1 rip 0xffffffff8190c2ac db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff80002659b360 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb> show proc PROC (syz-executor.4) tid=61994 pid=143 tcnt=2 stat=onproc flags process=0 proc=4000000 runpri=32, usrpri=79, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 forw=0xffffffffffffffff, list=0xffff80002170e558,0xffff80002170ed60 process=0xffff8000ffff6be0 user=0xffff800026596000, vmspace=0xfffffd807f013a10 estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 84121 74725 27901 0 2 0 syz-executor.7 84121 424997 27901 0 3 0x4000080 fsleep syz-executor.7 99630 315389 53132 0 2 0 syz-executor.3 99630 146014 53132 0 3 0x4000080 fsleep syz-executor.3 143 60948 48287 0 2 0 syz-executor.4 * 143 61994 48287 0 7 0x4000000 syz-executor.4 1352 249514 21784 0 2 0 syz-executor.2 1352 378511 21784 0 3 0x4000080 ttyout syz-executor.2 48936 315507 28709 0 3 0x82 nanoslp syz-executor.0 48287 62441 28709 0 3 0x82 nanoslp syz-executor.4 27901 65567 28709 0 3 0x82 nanoslp syz-executor.7 53132 34550 28709 0 3 0x82 nanoslp syz-executor.3 96784 377655 28709 0 3 0x82 piperd syz-executor.5 78073 119886 28709 0 3 0x2 biowait syz-executor.6 34894 188952 28709 0 3 0x2 biowait syz-executor.1 21784 102334 28709 0 3 0x82 nanoslp syz-executor.2 54991 496229 1 0 3 0x100083 ttyin getty 6203 516826 0 0 3 0x14280 nfsidl nfsio 34881 451706 0 0 3 0x14280 nfsidl nfsio 28706 492721 0 0 3 0x14280 nfsidl nfsio 10533 229149 0 0 3 0x14280 nfsidl nfsio 96666 456091 0 0 3 0x14280 nfsidl nfsio 10721 490866 0 0 3 0x14280 nfsidl nfsio 2630 200594 0 0 3 0x14280 nfsidl nfsio 76471 435944 0 0 3 0x14280 nfsidl nfsio 31063 422070 0 0 3 0x14280 nfsidl nfsio 56549 445501 0 0 3 0x14280 nfsidl nfsio 94670 506360 0 0 3 0x14280 nfsidl nfsio 25140 463392 0 0 3 0x14280 nfsidl nfsio 46883 222297 0 0 3 0x14280 nfsidl nfsio 43466 330995 0 0 3 0x14280 nfsidl nfsio 24755 520079 0 0 3 0x14280 nfsidl nfsio 62148 206356 0 0 3 0x14280 nfsidl nfsio 38540 35647 0 0 3 0x14280 nfsidl nfsio 30541 50474 0 0 3 0x14280 nfsidl nfsio 42382 6806 0 0 3 0x14280 nfsidl nfsio 82821 306345 0 0 3 0x14280 nfsidl nfsio 87296 496604 0 0 3 0x14200 bored sosplice 28709 322341 67454 0 3 0x2000082 thrsleep syz-fuzzer 28709 309549 67454 0 3 0x6000082 nanoslp syz-fuzzer 28709 386325 67454 0 3 0x6000082 wait syz-fuzzer 28709 402916 67454 0 3 0x6000082 wait syz-fuzzer 28709 117012 67454 0 3 0x6000082 thrsleep syz-fuzzer 28709 368887 67454 0 3 0x6000082 wait syz-fuzzer 28709 115687 67454 0 3 0x6000082 wait syz-fuzzer 28709 466111 67454 0 3 0x6000082 wait syz-fuzzer 28709 107490 67454 0 3 0x6000082 wait syz-fuzzer 28709 173968 67454 0 3 0x6000082 wait syz-fuzzer 28709 110551 67454 0 3 0x6000082 thrsleep syz-fuzzer 28709 264880 67454 0 2 0x6000002 syz-fuzzer 28709 160610 67454 0 3 0x6000082 wait syz-fuzzer 28709 170254 67454 0 3 0x6000082 thrsleep syz-fuzzer 67454 282259 44035 0 3 0x10008a sigsusp ksh 44035 101799 47315 0 3 0x9a kqread sshd 47315 41570 1 0 3 0x88 kqread sshd 33803 213992 3961 73 3 0x1100090 kqread syslogd 3961 93838 1 0 3 0x100082 netio syslogd 97767 272854 1 0 3 0x100080 kqread resolvd 78147 489052 93963 77 3 0x100092 kqread dhcpleased 11508 316607 93963 77 3 0x100092 kqread dhcpleased 93963 198284 1 0 3 0x80 kqread dhcpleased 3973 125869 0 0 3 0x14200 bored smr 31616 251774 0 0 2 0x14200 zerothread 32390 51120 0 0 3 0x14200 aiodoned aiodoned 16086 380226 0 0 3 0x14200 syncer update 53837 407198 0 0 3 0x14200 cleaner cleaner 12237 418246 0 0 3 0x14200 reaper reaper 97849 421507 0 0 3 0x14200 pgdaemon pagedaemon 34595 392471 0 0 3 0x14200 bored viomb 44619 44510 0 0 3 0x40014200 acpi0 acpi0 41428 247582 0 0 3 0x14200 bored softnet3 80045 497113 0 0 3 0x14200 bored softnet2 35048 226486 0 0 3 0x14200 bored softnet1 1005 144444 0 0 3 0x14200 bored softnet0 88894 202366 0 0 3 0x14200 bored systqmp 67555 257102 0 0 3 0x14200 bored systq 64845 522587 0 0 3 0x40014200 tmoslp softclock 87800 401158 0 0 3 0x40014200 idle0 1 463490 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 10214 6682K 7776K 78643K 47847 0 pcb 13 18K 23K 78643K 562 0 rtable 239 7K 7K 78643K 1258 0 pf 34 9K 10K 78643K 272 0 ifaddr 45 12K 13K 78643K 237 0 ifgroup 59 2K 2K 78643K 473 0 sysctl 3 0K 1K 78643K 10 0 counters 30 17K 17K 78643K 139 0 ioctlops 0 0K 2K 78643K 481 0 iov 1 0K 28K 78643K 1182 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1597 100K 100K 78643K 11166 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 126 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 1165 0 dirhash 12 2K 2K 78643K 69 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 14 49K 69K 78643K 8372 0 sigio 0 0K 0K 78643K 368 0 proc 67 59K 75K 78643K 1642 0 subproc 104 6K 6K 78643K 429 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 154 0 in_multi 99 7K 7K 78643K 488 0 ether_multi 1 0K 0K 78643K 14 0 mrt 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 97 440K 440K 78643K 97 0 exec 0 0K 1K 78643K 2428 0 pfkey data 0 0K 0K 78643K 3 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 426 469K 470K 78643K 78054 0 UVM aobj 131 4K 4K 78643K 137 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 136 0 NDP 15 0K 1K 78643K 188 0 temp 74 5916K 6196K 78643K 94010 0 kqueue 12 18K 26K 78643K 587 0 SYN cache 2 1236K 1244K 78643K 3 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 367 0 364 5 3 2 3 0 8 1 rtentry 112 402 0 291 5 1 4 4 0 8 0 unpcb 144 7138 0 7125 70 64 6 9 0 8 5 syncache 312 101 0 101 18 18 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 198 75 198 14 14 0 1 0 8 0 tcpcb 808 2754 0 2731 67 56 11 16 0 8 4 arp 88 71 0 53 1 0 1 1 0 8 0 ipq 40 6 0 6 4 4 0 1 0 8 0 ipqe 40 19 0 19 4 4 0 1 0 8 0 inpcb 336 7356 0 7330 91 82 9 14 0 8 3 nd6 104 106 0 81 1 0 1 1 0 8 0 pkpcb 40 53 0 53 5 4 1 1 0 8 1 kcovpl 48 33 0 25 1 0 1 1 0 8 0 ppxss 1160 21 0 21 6 6 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1591 0 1128 34 4 30 30 0 8 1 art_table 32 1592 0 1128 5 1 4 4 0 8 0 art_node 16 395 0 294 1 0 1 1 0 8 0 sysvmsgpl 40 20 0 20 1 1 0 1 0 8 0 semapl 112 1163 0 1153 1 0 1 1 0 8 0 shmpl 112 134 0 6 4 0 4 4 0 8 0 dirhash 1024 55 0 38 3 0 3 3 0 8 0 dino2pl 256 12826 0 11328 94 0 94 94 0 8 0 ffsino 240 12826 0 11328 89 0 89 89 0 8 0 nchpl 144 24257 0 23751 63 41 22 63 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 89595 0 89594 15 14 1 3 0 8 0 vcpupl 2048 55 0 0 7 0 7 7 0 8 0 vmpool 664 61 0 6 5 0 5 5 0 8 0 kstatmem 264 244 0 218 2 0 2 2 0 8 0 scxspl 216 85761 0 85759 31 27 4 8 1 8 3 plimitpl 152 1035 0 1020 1 0 1 1 0 8 0 sigapl 424 8639 0 8576 8 0 8 8 0 8 0 futexpl 64 82965 0 82963 6 5 1 1 0 8 0 knotepl 120 73164 0 73084 27 23 4 16 0 8 1 kqueuepl 184 1221 0 1213 16 14 2 4 0 8 1 pipepl 288 2489 0 2461 52 47 5 11 0 8 2 fdescpl 432 8600 0 8575 4 0 4 4 0 8 0 filepl 120 60490 0 60253 110 96 14 19 0 8 6 lockfpl 104 13016 0 13013 31 29 2 6 0 8 1 lockfspl 48 6133 0 6130 6 5 1 3 0 8 0 sessionpl 144 49 0 33 1 0 1 1 0 8 0 pgrppl 48 325 0 309 1 0 1 1 0 8 0 ucredpl 104 7681 0 7668 1 0 1 1 0 8 0 zombiepl 144 8577 0 8576 4 3 1 1 0 8 0 processpl 1008 8639 0 8576 10 1 9 9 0 8 0 procpl 680 20823 0 20743 21 13 8 9 0 8 0 sosppl 168 130 0 130 6 5 1 1 0 8 1 sockpl 456 14942 0 14900 291 274 17 35 0 8 8 mcl64k 65536 306 0 306 17 16 1 1 0 8 1 mcl16k 16384 166 0 166 19 18 1 1 0 8 1 mcl12k 12288 355 0 355 16 15 1 1 0 8 1 mcl9k 9216 117 0 117 15 14 1 1 0 8 1 mcl8k 8192 535 0 535 18 17 1 1 0 8 1 mcl4k 4096 1070 0 1070 15 14 1 2 0 8 1 mcl2k2 2112 57 0 57 23 22 1 1 0 8 1 mcl2k 2048 84467 0 84349 83 57 26 35 0 8 8 mtagpl 96 8388 0 7093 74 35 39 43 0 8 4 mbufpl 256 218105 0 216662 553 441 112 174 0 8 8 bufpl 288 20597 0 14197 459 1 458 458 0 8 0 anonpl 24 993271 0 981204 247 140 107 126 0 188 0 amapchunkpl 152 250043 0 249266 96 60 36 48 0 158 0 amappl16 200 22637 0 22103 145 115 30 42 0 8 0 amappl15 192 14 0 14 2 2 0 1 0 8 0 amappl14 184 233 0 222 2 1 1 2 0 8 0 amappl13 176 22 0 20 1 0 1 1 0 8 0 amappl12 168 9597 0 9569 2 0 2 2 0 8 0 amappl11 160 55 0 45 1 0 1 1 0 8 0 amappl10 152 49 0 41 2 1 1 1 0 8 0 amappl9 144 197 0 195 1 0 1 1 0 8 0 amappl8 136 473 0 377 4 0 4 4 0 8 0 amappl7 128 242 0 218 2 0 2 2 0 8 0 amappl6 120 669 0 656 1 0 1 1 0 8 0 amappl5 112 275 0 267 1 0 1 1 0 8 0 amappl4 104 628 0 605 2 1 1 2 0 8 0 amappl3 96 48832 0 48759 3 0 3 3 0 8 0 amappl2 88 9435 0 9365 3 0 3 3 0 8 0 amappl1 80 40546 0 40042 24 12 12 22 0 8 0 amappl 88 77131 0 76901 9 2 7 7 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 72 136 0 6 3 0 3 3 0 8 0 uaddrrnd 24 8661 0 8581 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 8661 0 8581 1 0 1 1 0 8 0 vmmpekpl 168 65378 0 65318 4 0 4 4 0 8 0 vmmpepl 168 523889 0 521610 320 195 125 154 0 357 8 vmsppl 368 8660 0 8581 8 0 8 8 0 8 0 rwobjpl 24 131694 0 124054 49 1 48 48 0 8 0 pdppl 4096 17328 0 17217 501 384 117 119 0 8 6 pvpl 32 2538584 0 2520973 556 371 185 334 0 265 0 pmappl 216 8660 0 8581 6 1 5 5 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 2168 0 1184 30 0 30 30 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8278176c) at panic+0x165 sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:357 bpfopen(31700,63,2000,ffff80002170d2c0) at bpfopen+0xc0 sys/net/bpf.c:391 spec_open_clone(ffff80002659b658) at spec_open_clone+0x208 spec_open(ffff80002659b658) at spec_open+0x401 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd806eea48a0,63,fffffd807f7d7618,ffff80002170d2c0) at VOP_OPEN+0x70 sys/kern/vfs_vops.c:138 vn_open(ffff80002659b8a8,63,0) at vn_open+0x452 sys/kern/vfs_vnops.c:177 doopenat(ffff80002170d2c0,ffffff9c,20000040,462,0,ffff80002659ba80) at doopenat+0x26e sys/kern/vfs_syscalls.c:1126 syscall(ffff80002659bb00) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xbb31581f790, count: -11 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8278176c) at panic+0x165 sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:357 bpfopen(31700,63,2000,ffff80002170d2c0) at bpfopen+0xc0 sys/net/bpf.c:391 spec_open_clone(ffff80002659b658) at spec_open_clone+0x208 spec_open(ffff80002659b658) at spec_open+0x401 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd806eea48a0,63,fffffd807f7d7618,ffff80002170d2c0) at VOP_OPEN+0x70 sys/kern/vfs_vops.c:138 vn_open(ffff80002659b8a8,63,0) at vn_open+0x452 sys/kern/vfs_vnops.c:177 doopenat(ffff80002170d2c0,ffffff9c,20000040,462,0,ffff80002659ba80) at doopenat+0x26e sys/kern/vfs_syscalls.c:1126 syscall(ffff80002659bb00) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xbb31581f790, count: -11