panic: Data modified on freelist: word 4 of object 0xffff800000d7a200 size 0x168 previous type free (0x6563 != 0xdead4110) Stopped at db_enter+0x1c: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *496990 31167 0 0 0x4000000 0 syz-executor.2 db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82769efd) at panic+0x165 sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:362 bpfopen(311700,63,2000,ffff80002b424878) at bpfopen+0xc0 sys/net/bpf.c:391 spec_open_clone(ffff80002e9088e8) at spec_open_clone+0x208 spec_open(ffff80002e9088e8) at spec_open+0x401 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd8073cfdcd8,63,fffffd807f7d7750,ffff80002b424878) at VOP_OPEN+0x70 sys/kern/vfs_vops.c:138 vn_open(ffff80002e908b38,63,0) at vn_open+0x452 sys/kern/vfs_vnops.c:177 doopenat(ffff80002b424878,ffffff9c,20000040,462,0,ffff80002e908d10) at doopenat+0x26e sys/kern/vfs_syscalls.c:1126 syscall(ffff80002e908d90) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe7bc5843900, 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 0xffff800000d7a200 size 0x168 previous type free (0x6563 != 0xdead4110) ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82769efd) at panic+0x165 sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:362 bpfopen(311700,63,2000,ffff80002b424878) at bpfopen+0xc0 sys/net/bpf.c:391 spec_open_clone(ffff80002e9088e8) at spec_open_clone+0x208 spec_open(ffff80002e9088e8) at spec_open+0x401 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd8073cfdcd8,63,fffffd807f7d7750,ffff80002b424878) at VOP_OPEN+0x70 sys/kern/vfs_vops.c:138 vn_open(ffff80002e908b38,63,0) at vn_open+0x452 sys/kern/vfs_vnops.c:177 doopenat(ffff80002b424878,ffffff9c,20000040,462,0,ffff80002e908d10) at doopenat+0x26e sys/kern/vfs_syscalls.c:1126 syscall(ffff80002e908d90) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe7bc5843900, count: -11 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002e908600 rbx 0xffff800000d7a200 rdx 0 rcx 0 rax 0xffff80002b424878 r8 0x101010101010101 r9 0x8080808080808080 r10 0x18c3b8f50af0d553 r11 0x495f71eee8257f41 r12 0 r13 0x51 r14 0 r15 0x1 rip 0xffffffff810d494c db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff80002e9085f0 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb> show proc PROC (syz-executor.2) pid=496990 stat=onproc flags process=0 proc=4000000 pri=80, usrpri=80, nice=20 forw=0xffffffffffffffff, list=0xffff80002b425b80,0xffff80002b4245d0 process=0xffff8000216fabd8 user=0xffff80002e903000, vmspace=0xfffffd8069d5d2f0 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 31167 270089 10098 0 2 0 syz-executor.2 *31167 496990 10098 0 7 0x4000000 syz-executor.2 31167 423331 10098 0 2 0x4000000 syz-executor.2 22667 186365 72703 0 2 0 syz-executor.6 22667 467747 72703 0 2 0x4000000 syz-executor.6 95426 81102 74873 60928 2 0x10 syz-executor.7 95426 522942 74873 60928 3 0x4000090 fsleep syz-executor.7 6506 344486 79108 0 2 0 syz-executor.3 6506 27196 79108 0 3 0x4000080 piperd syz-executor.3 90186 149839 60477 0 2 0 syz-executor.4 90186 167382 60477 0 3 0x4000080 ttyin syz-executor.4 84771 1698 0 0 3 0x14280 nfsidl nfsio 33263 239860 0 0 3 0x14280 nfsidl nfsio 90169 471831 0 0 3 0x14280 nfsidl nfsio 81813 346254 0 0 3 0x14280 nfsidl nfsio 32688 451787 0 0 3 0x14280 nfsidl nfsio 93326 339031 0 0 3 0x14280 nfsidl nfsio 8143 182303 0 0 3 0x14280 nfsidl nfsio 43075 420201 0 0 3 0x14280 nfsidl nfsio 62235 453779 0 0 3 0x14280 nfsidl nfsio 44871 228613 0 0 3 0x14280 nfsidl nfsio 59233 478882 0 0 3 0x14280 nfsidl nfsio 85493 374545 0 0 3 0x14280 nfsidl nfsio 55615 449321 0 0 3 0x14280 nfsidl nfsio 66290 358672 0 0 3 0x14280 nfsidl nfsio 17830 413099 0 0 3 0x14280 nfsidl nfsio 78838 100522 0 0 3 0x14280 nfsidl nfsio 55415 222645 0 0 3 0x14280 nfsidl nfsio 3114 390451 0 0 3 0x14280 nfsidl nfsio 7141 2386 0 0 3 0x14280 nfsidl nfsio 82063 102596 0 0 3 0x14280 nfsidl nfsio 93805 509063 0 0 3 0x14200 bored sosplice 79108 295925 8608 0 3 0x82 nanoslp syz-executor.3 72703 177723 8608 0 3 0x82 nanoslp syz-executor.6 47027 245177 8608 0 3 0x82 nanoslp syz-executor.5 60477 119309 8608 0 3 0x82 nanoslp syz-executor.4 77049 411484 8608 0 2 0x2 syz-executor.1 74873 113089 8608 0 3 0x82 nanoslp syz-executor.7 10098 482953 8608 0 3 0x82 nanoslp syz-executor.2 67098 267134 8608 0 3 0x82 nanoslp syz-executor.0 8608 410339 66997 0 3 0x82 wait syz-fuzzer 8608 405273 66997 0 3 0x4000082 nanoslp syz-fuzzer 8608 261510 66997 0 3 0x4000082 wait syz-fuzzer 8608 447820 66997 0 3 0x4000082 wait syz-fuzzer 8608 148875 66997 0 3 0x4000082 wait syz-fuzzer 8608 186952 66997 0 3 0x4000082 thrsleep syz-fuzzer 8608 82646 66997 0 3 0x4000082 thrsleep syz-fuzzer 8608 266959 66997 0 3 0x4000082 wait syz-fuzzer 8608 458161 66997 0 3 0x4000082 wait syz-fuzzer 8608 310111 66997 0 3 0x4000082 thrsleep syz-fuzzer 8608 209518 66997 0 3 0x4000082 wait syz-fuzzer 8608 392091 66997 0 3 0x4000082 wait syz-fuzzer 8608 149244 66997 0 3 0x4000082 kqread syz-fuzzer 8608 160790 66997 0 3 0x4000082 thrsleep syz-fuzzer 66997 193426 2703 0 3 0x10008a sigsusp ksh 2703 298640 35868 0 3 0x9a kqread sshd 24847 468866 1 0 3 0x100083 ttyin getty 35868 62883 1 0 3 0x88 kqread sshd 6862 378220 83418 73 3 0x1100090 kqread syslogd 83418 161053 1 0 3 0x100082 netio syslogd 17889 26862 1 0 3 0x100080 kqread resolvd 46672 418507 79796 77 3 0x100092 kqread dhcpleased 7649 306642 79796 77 3 0x100092 kqread dhcpleased 79796 451048 1 0 3 0x80 kqread dhcpleased 73651 217315 0 0 3 0x14200 bored smr 97563 327883 0 0 2 0x14200 zerothread 89668 206145 0 0 3 0x14200 aiodoned aiodoned 7025 184135 0 0 3 0x14200 syncer update 17475 252804 0 0 3 0x14200 cleaner cleaner 45339 87551 0 0 3 0x14200 reaper reaper 46053 277692 0 0 3 0x14200 pgdaemon pagedaemon 19005 243333 0 0 3 0x14200 bored viomb 94106 444314 0 0 3 0x40014200 acpi0 acpi0 7908 414147 0 0 3 0x14200 bored softnet3 62809 306594 0 0 3 0x14200 bored softnet2 16570 167834 0 0 3 0x14200 bored softnet1 19030 467764 0 0 3 0x14200 bored softnet0 42345 152502 0 0 3 0x14200 bored systqmp 73511 187593 0 0 3 0x14200 bored systq 78743 299330 0 0 3 0x40014200 bored softclock 70819 372078 0 0 3 0x40014200 idle0 1 357808 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 10260 6640K 7239K 78643K 14096 0 pcb 13 10K 12K 78643K 29 0 rtable 243 7K 7K 78643K 409 0 pf 29 8K 9K 78643K 44 0 ifaddr 43 11K 11K 78643K 53 0 ifgroup 50 2K 2K 78643K 71 0 sysctl 3 1K 1K 78643K 3 0 counters 28 17K 17K 78643K 34 0 ioctlops 0 0K 2K 78643K 35 0 iov 0 0K 12K 78643K 37 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1576 99K 99K 78643K 2308 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 13 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 173 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 15 53K 77K 78643K 1495 0 sigio 0 0K 0K 78643K 7 0 proc 57 59K 75K 78643K 501 0 subproc 104 6K 6K 78643K 108 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 14 0 in_multi 99 7K 7K 78643K 99 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 67 307K 307K 78643K 67 0 exec 0 0K 1K 78643K 508 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 305 84K 85K 78643K 15911 0 UVM aobj 120 15K 15K 78643K 120 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 16 0 NDP 11 0K 1K 78643K 33 0 temp 57 5852K 5931K 78643K 24103 0 kqueue 12 18K 24K 78643K 114 0 SYN cache 2 16K 16K 78643K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 78 0 75 2 0 2 2 0 8 1 rtentry 112 115 0 2 4 0 4 4 0 8 0 unpcb 144 506 0 493 6 3 3 4 0 8 2 syncache 296 13 0 13 4 3 1 1 0 8 1 tcpqe 32 179 0 179 5 4 1 1 0 8 1 tcpcb 808 127 0 123 1 0 1 1 0 8 0 arp 88 18 0 0 1 0 1 1 0 8 0 ipq 40 1 0 0 1 0 1 1 0 8 0 ipqe 40 4 0 3 1 0 1 1 0 8 0 inpcb 336 1244 0 1236 18 13 5 12 0 8 4 nd6 104 28 0 1 1 0 1 1 0 8 0 pkpcb 40 3 0 3 1 1 0 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 ppxss 1160 3 0 3 1 1 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 465 0 7 29 0 29 29 0 8 0 art_table 32 466 0 7 4 0 4 4 0 8 0 art_node 16 114 0 11 1 0 1 1 0 8 0 sysvmsgpl 40 89 0 86 3 2 1 1 0 8 0 semapl 112 171 0 161 1 0 1 1 0 8 0 shmpl 112 117 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 3213 0 1775 91 0 91 91 0 8 0 ffsino 240 3213 0 1775 85 0 85 85 0 8 0 nchpl 144 5294 0 3613 63 0 63 63 0 8 0 uvmvnodes 80 4225 0 0 87 0 87 87 0 8 0 vnodes 216 4225 0 0 235 0 235 235 0 8 0 namei 1024 19717 0 19717 4 3 1 3 0 8 1 kstatmem 264 34 0 12 2 0 2 2 0 8 0 scxspl 216 18998 0 18998 11 10 1 8 0 8 1 plimitpl 152 36 0 21 1 0 1 1 0 8 0 sigapl 424 1877 0 1812 9 1 8 8 0 8 0 futexpl 64 12596 0 12595 1 0 1 1 0 8 0 knotepl 120 15769 0 15689 4 0 4 4 0 8 0 kqueuepl 184 221 0 213 4 3 1 4 0 8 0 pipepl 288 498 0 469 11 8 3 11 0 8 0 fdescpl 432 1780 0 1754 4 0 4 4 0 8 0 filepl 120 8820 0 8535 24 14 10 15 0 8 1 lockfpl 104 969 0 920 6 4 2 5 0 8 0 lockfspl 48 505 0 456 3 2 1 3 0 8 0 sessionpl 144 23 0 7 1 0 1 1 0 8 0 pgrppl 48 23 0 7 1 0 1 1 0 8 0 ucredpl 104 1212 0 1199 1 0 1 1 0 8 0 zombiepl 144 1814 0 1812 1 0 1 1 0 8 0 processpl 1008 1877 0 1812 11 2 9 9 0 8 0 procpl 696 3982 0 3898 11 2 9 9 0 8 0 sosppl 168 15 0 15 3 3 0 1 0 8 0 sockpl 456 1902 0 1878 34 24 10 20 0 8 7 mcl64k 65536 50 0 50 2 1 1 1 0 8 1 mcl16k 16384 15 0 15 2 1 1 1 0 8 1 mcl12k 12288 48 0 48 4 3 1 1 0 8 1 mcl9k 9216 26 0 26 3 2 1 1 0 8 1 mcl8k 8192 64 0 64 3 2 1 1 0 8 1 mcl4k 4096 158 0 158 1 0 1 1 0 8 1 mcl2k2 2112 11 0 11 4 4 0 1 0 8 0 mcl2k 2048 56740 0 56689 42 33 9 29 0 8 1 mtagpl 96 223 0 26 6 1 5 5 0 8 0 mbufpl 256 106491 0 106174 82 49 33 72 0 8 4 bufpl 288 7018 0 630 457 0 457 457 0 8 0 anonpl 24 349130 0 338195 113 25 88 92 0 188 17 amapchunkpl 152 52719 0 51947 46 12 34 42 0 158 2 amappl16 200 9636 0 9342 43 23 20 29 0 8 4 amappl15 192 17 0 17 1 1 0 1 0 8 0 amappl14 184 163 0 150 2 1 1 2 0 8 0 amappl13 176 15 0 15 2 1 1 1 0 8 1 amappl12 168 2411 0 2384 2 0 2 2 0 8 0 amappl11 160 55 0 43 1 0 1 1 0 8 0 amappl10 152 27 0 17 2 1 1 1 0 8 0 amappl9 144 167 0 166 2 1 1 2 0 8 0 amappl8 136 191 0 140 2 0 2 2 0 8 0 amappl7 128 56 0 45 1 0 1 1 0 8 0 amappl6 120 262 0 246 2 1 1 2 0 8 0 amappl5 112 160 0 152 1 0 1 1 0 8 0 amappl4 104 597 0 567 2 1 1 2 0 8 0 amappl3 96 10476 0 10398 4 1 3 3 0 8 0 amappl2 88 2016 0 1959 4 2 2 3 0 8 0 amappl1 80 14687 0 14188 22 10 12 22 0 8 0 amappl 88 15378 0 15175 6 0 6 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 72 119 0 0 3 0 3 3 0 8 0 uaddrrnd 24 1780 0 1754 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1780 0 1754 1 0 1 1 0 8 0 vmmpekpl 168 18332 0 18284 3 0 3 3 0 8 0 vmmpepl 168 125945 0 123942 130 29 101 112 0 357 9 vmsppl 368 1779 0 1754 3 0 3 3 0 8 0 rwobjpl 24 42531 0 36928 35 1 34 34 0 8 0 pdppl 4096 3566 0 3508 150 88 62 70 0 8 4 pvpl 32 761734 0 745610 360 83 277 360 0 265 141 pmappl 216 1779 0 1754 2 0 2 2 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 988 0 200 24 0 24 24 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(ffffffff82769efd) at panic+0x165 sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:362 bpfopen(311700,63,2000,ffff80002b424878) at bpfopen+0xc0 sys/net/bpf.c:391 spec_open_clone(ffff80002e9088e8) at spec_open_clone+0x208 spec_open(ffff80002e9088e8) at spec_open+0x401 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd8073cfdcd8,63,fffffd807f7d7750,ffff80002b424878) at VOP_OPEN+0x70 sys/kern/vfs_vops.c:138 vn_open(ffff80002e908b38,63,0) at vn_open+0x452 sys/kern/vfs_vnops.c:177 doopenat(ffff80002b424878,ffffff9c,20000040,462,0,ffff80002e908d10) at doopenat+0x26e sys/kern/vfs_syscalls.c:1126 syscall(ffff80002e908d90) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe7bc5843900, 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(ffffffff82769efd) at panic+0x165 sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:362 bpfopen(311700,63,2000,ffff80002b424878) at bpfopen+0xc0 sys/net/bpf.c:391 spec_open_clone(ffff80002e9088e8) at spec_open_clone+0x208 spec_open(ffff80002e9088e8) at spec_open+0x401 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd8073cfdcd8,63,fffffd807f7d7750,ffff80002b424878) at VOP_OPEN+0x70 sys/kern/vfs_vops.c:138 vn_open(ffff80002e908b38,63,0) at vn_open+0x452 sys/kern/vfs_vnops.c:177 doopenat(ffff80002b424878,ffffff9c,20000040,462,0,ffff80002e908d10) at doopenat+0x26e sys/kern/vfs_syscalls.c:1126 syscall(ffff80002e908d90) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe7bc5843900, count: -11