panic: Data modified on freelist: word 4 of object 0xffff800001727000 size 0x168 previous type free (0x0 != 0xdeaf4152) Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 64897 58774 0 0 0x4000000 0 syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833d9b9c) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xdb6 sys/kern/kern_malloc.c:357 bpfopen(31700,101,2000,ffff80002a79d240) at bpfopen+0xeb sys/net/bpf.c:-1 spec_open_clone(ffff80002a803858) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722 spec_open(ffff80002a803858) at spec_open+0x316 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd806f86b1e0,101,fffffd8007ffd9c0,ffff80002a79d240) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138 vn_open(ffff80002a803aa0,101,0) at vn_open+0x6a0 sys/kern/vfs_vnops.c:177 doopenat(ffff80002a79d240,ffffff9c,200000000240,100,0,0,2f836590ba787c88) at doopenat+0x352 sys/kern/vfs_syscalls.c:1155 sys_openat(ffff80002a79d240,ffff80002a803d40,ffff80002a803c90) at sys_openat+0x58 sys/kern/vfs_syscalls.c:1094 syscall(ffff80002a803d40) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80002a803d40) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x20ba43b4020, count: 3 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 0xffff800001727000 size 0x168 previous type free (0x0 != 0xdeaf4152) ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833d9b9c) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xdb6 sys/kern/kern_malloc.c:357 bpfopen(31700,101,2000,ffff80002a79d240) at bpfopen+0xeb sys/net/bpf.c:-1 spec_open_clone(ffff80002a803858) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722 spec_open(ffff80002a803858) at spec_open+0x316 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd806f86b1e0,101,fffffd8007ffd9c0,ffff80002a79d240) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138 vn_open(ffff80002a803aa0,101,0) at vn_open+0x6a0 sys/kern/vfs_vnops.c:177 doopenat(ffff80002a79d240,ffffff9c,200000000240,100,0,0,2f836590ba787c88) at doopenat+0x352 sys/kern/vfs_syscalls.c:1155 sys_openat(ffff80002a79d240,ffff80002a803d40,ffff80002a803c90) at sys_openat+0x58 sys/kern/vfs_syscalls.c:1094 syscall(ffff80002a803d40) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80002a803d40) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x20ba43b4020, count: -12 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002a803580 rbx 0xffff800001727000 rdx 0 rcx 0 rax 0xffff80002a79d240 r8 0x101010101010101 r9 0x8080808080808080 r10 0x911d7d6763a42a96 r11 0xcacbebbe2041e769 r12 0 r13 0xffffffff83a66af0 kmemstats+0x80 r14 0 r15 0x1 rip 0xffffffff82289575 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a803570 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (syz-executor) tid=64897 pid=58774 tcnt=2 stat=onproc flags process=0 proc=4000000 runpri=32, usrpri=86, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a79d4d8,0xffff80002a79ca88 process=0xffff8000ffff9698 user=0xffff80002a7fe000, vmspace=0xfffffd806cccc740 estcpu=36, cpticks=2, pctcpu=0.0, user=0, sys=2, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 58774 213556 46972 0 2 0 syz-executor *58774 64897 46972 0 7 0x4000000 syz-executor 22715 515215 91718 0 2 0 syz-executor 22715 63476 91718 0 3 0x4000080 fsleep syz-executor 96888 490175 47868 0 2 0 syz-executor 96888 40732 47868 0 3 0x4000080 fsleep syz-executor 69850 330428 45314 0 3 0x2 clonelk syz-executor 30928 493391 45314 0 2 0x2 syz-executor 86318 284946 0 0 3 0x14200 acct acct 47884 337369 0 0 3 0x14280 nfsidl nfsio 74172 393119 0 0 3 0x14280 nfsidl nfsio 44921 101989 0 0 3 0x14280 nfsidl nfsio 28736 479356 0 0 3 0x14280 nfsidl nfsio 47868 100254 45314 0 3 0x82 nanoslp syz-executor 31404 158948 45314 0 3 0x82 wait syz-executor 1346 295632 45314 0 3 0x82 nanoslp syz-executor 30801 489243 45314 0 3 0x82 nanoslp syz-executor 46972 367647 45314 0 3 0x82 nanoslp syz-executor 91718 185052 45314 0 3 0x82 nanoslp syz-executor 45314 177390 12621 0 3 0x82 kqread syz-executor 12621 440467 58822 0 3 0x10008a sigsusp ksh 58822 152891 35541 0 3 0x98 kqread sshd-session 35541 169629 527 0 3 0x92 kqread sshd-session 97408 386276 1 0 3 0x100083 ttyopn getty 527 320597 1 0 3 0x88 kqread sshd 5456 157554 52544 73 3 0x1100090 kqread syslogd 52544 272221 1 0 3 0x100082 sbwait syslogd 52243 449195 1 0 3 0x100080 kqread resolvd 84028 172721 32488 77 3 0x100092 kqread dhcpleased 44685 425685 32488 77 3 0x100092 kqread dhcpleased 32488 255303 1 0 3 0x80 kqread dhcpleased 74650 72708 0 0 3 0x14200 bored smr 97522 312157 0 0 2 0x14200 zerothread 50197 317796 0 0 3 0x14200 aiodoned aiodoned 61844 349858 0 0 3 0x14200 syncer update 70715 421865 0 0 3 0x14200 cleaner cleaner 11147 115257 0 0 3 0x14200 reaper reaper 86754 386401 0 0 3 0x14200 pgdaemon pagedaemon 29386 75643 0 0 3 0x14200 bored viomb 52892 260573 0 0 3 0x40014200 acpi0 acpi0 21275 263498 0 0 3 0x14200 bored softnet0 87369 308983 0 0 3 0x14200 bored systqmp 76260 264489 0 0 3 0x14200 bored systq 54792 488938 0 0 3 0x40014200 tmoslp softclock 93713 104836 0 0 3 0x40014200 idle0 1 448188 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11074 12113K 12884K 166960K 13928 0 pcb 17 16K 17K 166960K 322 0 rtable 180 9K 10K 166960K 608 0 pf 34 14K 17K 166960K 160 0 ifaddr 31 5K 8K 166960K 113 0 ifgroup 46 2K 2K 166960K 187 0 sysctl 4 1K 9K 166960K 16 0 counters 32 17K 18K 166960K 104 0 ioctlops 0 0K 4K 166960K 459 0 iov 0 0K 16K 166960K 72 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1452 91K 92K 166960K 2497 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 7 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 65 0 dirhash 12 2K 2K 166960K 15 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 16 57K 97K 166960K 951 0 sigio 0 0K 0K 166960K 115 0 proc 60 59K 124K 166960K 691 0 subproc 72 4K 4K 166960K 135 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 114 0 in_multi 59 4K 7K 166960K 160 0 ether_multi 1 0K 0K 166960K 13 0 mrt 1 0K 0K 166960K 27 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 259 1155K 1155K 166960K 259 0 exec 0 0K 1K 166960K 615 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 3 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 215 151K 158K 166960K 9860 0 UVM aobj 18 8K 8K 166960K 24 0 pinsyscall 37 74K 96K 166960K 2146 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 45 0 NDP 10 0K 2K 166960K 81 0 temp 80 9076K 9331K 166960K 41182 0 kqueue 14 20K 30K 166960K 176 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 85 0 82 1 0 1 1 0 8 0 rtentry 136 158 0 91 4 0 4 4 0 8 0 unpcb 144 1075 0 1060 6 0 6 6 0 8 5 syncache 336 8 0 8 1 0 1 1 0 8 1 tcpqe 32 2 0 2 1 0 1 1 0 8 1 tcpcb 736 390 0 384 7 0 7 7 0 8 6 arp 96 23 0 11 1 0 1 1 0 8 0 ipq 40 3 0 1 1 0 1 1 0 8 0 ipqe 40 5 0 3 1 0 1 1 0 8 0 inpcb 328 1104 0 1094 7 0 7 7 0 8 4 nd6 112 37 0 23 1 0 1 1 0 8 0 pkpcb 40 10 0 10 1 0 1 1 0 8 1 kcovpl 48 15 0 7 1 0 1 1 0 8 0 ppxss 1072 55 0 55 1 0 1 1 0 8 1 pppxif 1384 6 0 6 1 0 1 1 0 8 1 pfstscr 40 1 0 1 1 0 1 1 0 8 1 pfrktable 1344 2 0 1 1 0 1 1 0 8 0 pfsrclim 320 3 0 2 1 0 1 1 0 8 0 pfstlim 224 33 0 32 1 0 1 1 0 8 0 pftag 88 2 0 0 1 0 1 1 0 8 0 pfqueue 320 1 0 0 1 0 1 1 0 8 0 pfstitem 24 3 0 0 1 0 1 1 0 8 0 pfstkey 128 11 0 9 1 0 1 1 0 8 0 pfstate 384 6 0 4 1 0 1 1 0 8 0 pfrule 1360 6 0 6 1 0 1 1 0 8 1 rttmr 136 1 0 1 1 0 1 1 0 8 1 art_heap8 4096 3 0 0 3 0 3 3 0 8 0 art_heap4 256 666 0 369 31 0 31 31 0 8 8 art_table 40 669 0 369 5 0 5 5 0 8 0 art_node 32 157 0 96 1 0 1 1 0 8 0 sysvmsgpl 40 37 0 37 1 0 1 1 0 8 1 semapl 112 63 0 53 1 0 1 1 0 8 0 shmpl 112 18 0 5 1 0 1 1 0 8 0 dirhash 1024 19 0 2 3 0 3 3 0 8 0 dino2pl 256 3142 0 1682 92 0 92 92 0 8 0 ffsino 256 3142 0 1682 92 0 92 92 0 8 0 nchpl 144 4402 0 2691 64 0 64 64 0 8 0 rtmask 32 9 0 9 1 0 1 1 0 8 1 vnodes 216 3999 0 0 223 0 223 223 0 8 0 namei 1024 15827 0 15827 2 0 2 2 0 8 2 vcpupl 3904 3 0 1 1 0 1 1 0 8 0 vmpool 808 3 0 1 1 0 1 1 0 8 0 kstatmem 264 122 0 102 3 0 3 3 0 8 1 scsiplug 72 7 0 7 1 0 1 1 0 8 1 scxspl 216 18566 0 18566 8 0 8 8 1 8 8 plimitpl 152 379 0 363 1 0 1 1 0 8 0 sigapl 424 1240 0 1194 6 0 6 6 0 8 0 knotepl 120 37784 0 37735 45 34 11 23 0 8 8 kqueuepl 184 381 0 371 4 0 4 4 0 8 3 pipepl 304 204 0 177 3 0 3 3 0 8 0 fdescpl 448 1221 0 1193 5 0 5 5 0 8 1 filepl 120 8644 0 8427 14 0 14 14 0 8 4 lockfpl 104 428 0 426 1 0 1 1 0 8 0 lockfspl 48 131 0 129 1 0 1 1 0 8 0 sessionpl 144 32 0 24 1 0 1 1 0 8 0 pgrppl 48 53 0 37 1 0 1 1 0 8 0 ucredpl 104 1350 0 1337 1 0 1 1 0 8 0 zombiepl 144 1197 0 1194 1 0 1 1 0 8 0 processpl 1152 1240 0 1194 4 0 4 4 0 8 0 procpl 664 2446 0 2397 6 0 6 6 0 8 0 sosppl 176 3 0 3 1 0 1 1 0 8 1 sockpl 552 2407 0 2379 16 4 12 14 0 8 8 mcl64k 65536 74 0 74 1 0 1 1 0 8 1 mcl16k 16384 2 0 2 1 0 1 1 0 8 1 mcl12k 12288 1 0 1 1 0 1 1 0 8 1 mcl9k 9216 2 0 2 1 0 1 1 0 8 1 mcl8k 8192 10 0 10 1 0 1 1 0 8 1 mcl4k 4096 3463 0 3411 13 0 13 13 0 8 6 mcl2k 2048 1048 0 1039 4 0 4 4 0 8 2 mtagpl 96 24 0 11 1 0 1 1 0 8 0 mbufpl 256 16920 0 16764 80 57 23 80 0 8 8 bufpl 280 7511 0 1293 445 0 445 445 0 8 0 anonpl 24 204554 0 199420 64 0 64 64 0 187 25 amapchunkpl 152 32997 0 32419 29 0 29 29 0 158 2 amappl16 200 4100 0 4076 36 23 13 25 0 8 8 amappl15 192 7 0 7 1 0 1 1 0 8 1 amappl14 184 470 0 469 1 0 1 1 0 8 0 amappl13 176 143 0 133 1 0 1 1 0 8 0 amappl12 168 1474 0 1447 2 0 2 2 0 8 0 amappl11 160 16 0 16 1 0 1 1 0 8 1 amappl10 152 60 0 50 1 0 1 1 0 8 0 amappl9 144 263 0 262 1 0 1 1 0 8 0 amappl8 136 130 0 129 1 0 1 1 0 8 0 amappl7 128 57 0 55 1 0 1 1 0 8 0 amappl6 120 295 0 285 1 0 1 1 0 8 0 amappl5 112 82 0 74 1 0 1 1 0 8 0 amappl4 104 489 0 459 1 0 1 1 0 8 0 amappl3 96 5623 0 5539 3 0 3 3 0 8 0 amappl2 88 1306 0 1244 2 0 2 2 0 8 0 amappl1 80 13568 0 13039 13 0 13 13 0 8 0 amappl 88 8953 0 8801 5 0 5 5 0 92 0 uvmvnodes 80 131 0 0 3 0 3 3 0 8 0 dma32768 32768 1 0 1 1 0 1 1 0 8 1 dma4096 4096 2 0 2 1 0 1 1 0 8 1 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 7 0 7 1 0 1 1 0 8 1 dma128 128 257 0 257 1 0 1 1 0 8 1 dma64 64 6 0 6 1 0 1 1 0 8 1 dma32 32 7 0 7 1 0 1 1 0 8 1 dma16 16 19 0 18 1 0 1 1 0 8 0 aobjpl 72 23 0 6 1 0 1 1 0 8 0 uaddrrnd 24 1221 0 1193 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1221 0 1193 1 0 1 1 0 8 0 vmmpekpl 168 11287 0 11246 3 0 3 3 0 8 0 vmmpepl 168 84497 0 82772 99 0 99 99 0 357 14 vmsppl 368 1220 0 1193 4 0 4 4 0 8 1 rwobjpl 40 24787 0 23810 15 0 15 15 0 8 1 pdppl 4096 2454 0 2390 105 36 69 82 0 8 5 pvpl 32 547101 0 536767 144 0 144 144 0 265 41 pmappl 216 1223 0 1194 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 451 0 93 12 0 12 12 0 8 1 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833d9b9c) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xdb6 sys/kern/kern_malloc.c:357 bpfopen(31700,101,2000,ffff80002a79d240) at bpfopen+0xeb sys/net/bpf.c:-1 spec_open_clone(ffff80002a803858) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722 spec_open(ffff80002a803858) at spec_open+0x316 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd806f86b1e0,101,fffffd8007ffd9c0,ffff80002a79d240) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138 vn_open(ffff80002a803aa0,101,0) at vn_open+0x6a0 sys/kern/vfs_vnops.c:177 doopenat(ffff80002a79d240,ffffff9c,200000000240,100,0,0,2f836590ba787c88) at doopenat+0x352 sys/kern/vfs_syscalls.c:1155 sys_openat(ffff80002a79d240,ffff80002a803d40,ffff80002a803c90) at sys_openat+0x58 sys/kern/vfs_syscalls.c:1094 syscall(ffff80002a803d40) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80002a803d40) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x20ba43b4020, count: -12 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833d9b9c) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(168,2,a) at malloc+0xdb6 sys/kern/kern_malloc.c:357 bpfopen(31700,101,2000,ffff80002a79d240) at bpfopen+0xeb sys/net/bpf.c:-1 spec_open_clone(ffff80002a803858) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722 spec_open(ffff80002a803858) at spec_open+0x316 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd806f86b1e0,101,fffffd8007ffd9c0,ffff80002a79d240) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138 vn_open(ffff80002a803aa0,101,0) at vn_open+0x6a0 sys/kern/vfs_vnops.c:177 doopenat(ffff80002a79d240,ffffff9c,200000000240,100,0,0,2f836590ba787c88) at doopenat+0x352 sys/kern/vfs_syscalls.c:1155 sys_openat(ffff80002a79d240,ffff80002a803d40,ffff80002a803c90) at sys_openat+0x58 sys/kern/vfs_syscalls.c:1094 syscall(ffff80002a803d40) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80002a803d40) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x20ba43b4020, count: -12