panic: Data modified on freelist: word 4 of object 0xffff800000a13000 size 0x1800 previous type free (0x0 != 0xdeaf4152) Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *155145 4061 0 0 0x4000000 0 syz-executor.1 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821d6175) at panic+0x15c sys/kern/subr_prf.c:207 malloc(1800,2,9) at malloc+0xa23 sys/kern/kern_malloc.c:331 wsevent_init(ffff800000653c50) at wsevent_init+0x49 sys/dev/wscons/wsevent.c:109 wsmouseopen(4400,1,2000,ffff80001d7394e8) at wsmouseopen+0x11e sys/dev/wscons/wsmouse.c:331 spec_open(ffff8000208429f8) at spec_open+0x3ea sys/kern/spec_vnops.c:157 VOP_OPEN(fffffd806854c4e0,1,fffffd806c3bfba0,ffff80001d7394e8) at VOP_OPEN+0x6a sys/kern/vfs_vops.c:153 vn_open(ffff800020842c48,1,0) at vn_open+0x490 sys/kern/vfs_vnops.c:183 doopenat(ffff80001d7394e8,ffffff9c,20000000,0,0,ffff800020842e40) at doopenat+0x28b sys/kern/vfs_syscalls.c:1141 syscall(ffff800020842ec0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x8503aeac100, 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 Data modified on freelist: word 4 of object 0xffff800000a13000 size 0x1800 previous type free (0x0 != 0xdeaf4152) ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821d6175) at panic+0x15c sys/kern/subr_prf.c:207 malloc(1800,2,9) at malloc+0xa23 sys/kern/kern_malloc.c:331 wsevent_init(ffff800000653c50) at wsevent_init+0x49 sys/dev/wscons/wsevent.c:109 wsmouseopen(4400,1,2000,ffff80001d7394e8) at wsmouseopen+0x11e sys/dev/wscons/wsmouse.c:331 spec_open(ffff8000208429f8) at spec_open+0x3ea sys/kern/spec_vnops.c:157 VOP_OPEN(fffffd806854c4e0,1,fffffd806c3bfba0,ffff80001d7394e8) at VOP_OPEN+0x6a sys/kern/vfs_vops.c:153 vn_open(ffff800020842c48,1,0) at vn_open+0x490 sys/kern/vfs_vnops.c:183 doopenat(ffff80001d7394e8,ffffff9c,20000000,0,0,ffff800020842e40) at doopenat+0x28b sys/kern/vfs_syscalls.c:1141 syscall(ffff800020842ec0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x8503aeac100, count: -11 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800020842740 rbx 0xffff8000208427f0 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff8134a72f kprintf+0x15f r9 0x1 r10 0x2 r11 0x78db2ba2d959cdd3 r12 0x3000000008 r13 0xffff800020842750 r14 0x100 r15 0x1 rip 0xffffffff8209e758 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020842730 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (syz-executor.1) pid=155145 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff80001d73a868,0xffffffff825a7868 process=0xffff8000ffffb938 user=0xffff80002083d000, vmspace=0xfffffd806bc0a660 estcpu=1, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 4061 55251 72794 0 2 0 syz-executor.1 * 4061 155145 72794 0 7 0x4000000 syz-executor.1 50544 20437 28884 0 3 0x2 biowait syz-executor.0 72794 423603 28884 0 3 0x82 nanosleep syz-executor.1 28884 486281 56314 0 3 0x82 thrsleep syz-fuzzer 28884 214087 56314 0 2 0x4000002 syz-fuzzer 28884 263437 56314 0 3 0x4000082 kqread syz-fuzzer 28884 489360 56314 0 3 0x4000082 thrsleep syz-fuzzer 28884 177873 56314 0 3 0x4000082 thrsleep syz-fuzzer 28884 196758 56314 0 3 0x4000082 thrsleep syz-fuzzer 28884 470353 56314 0 3 0x4000082 thrsleep syz-fuzzer 56314 266809 5938 0 3 0x10008a pause ksh 5938 313139 4722 0 3 0x92 select sshd 68455 311571 1 0 3 0x100083 ttyin getty 4722 320501 1 0 3 0x80 select sshd 32797 73959 23128 73 3 0x100090 kqread syslogd 23128 163359 1 0 3 0x100082 netio syslogd 92748 257882 1 77 3 0x100090 poll dhclient 46530 137651 1 0 3 0x80 poll dhclient 51958 311448 0 0 3 0x14200 bored smr 33074 82194 0 0 2 0x14200 zerothread 3072 263820 0 0 3 0x14200 aiodoned aiodoned 49341 268523 0 0 3 0x14200 syncer update 9841 279939 0 0 3 0x14200 cleaner cleaner 54668 79945 0 0 3 0x14200 reaper reaper 61896 200645 0 0 3 0x14200 pgdaemon pagedaemon 33435 62526 0 0 3 0x14200 bored crynlk 54038 188069 0 0 3 0x14200 bored crypto 13978 43410 0 0 3 0x40014200 acpi0 acpi0 7189 151222 0 0 3 0x14200 bored softnet 93317 505949 0 0 3 0x14200 bored systqmp 78440 81487 0 0 3 0x14200 bored systq 56932 161681 0 0 3 0x40014200 bored softclock 72462 353546 0 0 3 0x40014200 idle0 1 390685 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 9450 6332K 6332K 78643K 10551 0 pcb 13 8K 8K 78643K 21 0 rtable 105 3K 3K 78643K 189 0 ifaddr 39 10K 10K 78643K 41 0 counters 21 16K 16K 78643K 21 0 ioctlops 0 0K 2K 78643K 16 0 mount 1 1K 1K 78643K 1 0 vnodes 1216 76K 77K 78643K 1223 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 1K 78643K 2 0 VM map 2 0K 0K 78643K 2 0 sem 2 0K 0K 78643K 2 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 5 13K 25K 78643K 42 0 proc 47 38K 54K 78643K 358 0 subproc 32 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 1 0 in_multi 33 2K 2K 78643K 35 0 ether_multi 1 0K 0K 78643K 2 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 31 148K 148K 78643K 31 0 exec 0 0K 1K 78643K 181 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 115 22K 23K 78643K 926 0 UVM aobj 2 2K 2K 78643K 2 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 10 0 NDP 5 0K 0K 78643K 9 0 temp 60 3027K 3091K 78643K 1781 0 kqueue 3 4K 4K 78643K 3 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 arp 64 6 0 0 1 0 1 1 0 8 0 rtpcb 80 19 0 17 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 39 0 30 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 71 0 71 2 1 1 1 0 8 1 tcpcb 544 18 0 14 1 0 1 1 0 8 0 inpcb 280 52 0 45 1 0 1 1 0 8 0 nd6 48 6 0 0 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 189 0 0 12 0 12 12 0 8 0 art_table 32 190 0 0 2 0 2 2 0 8 0 art_node 16 44 0 4 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1428 0 30 88 0 88 88 0 8 0 ffsino 240 1428 0 30 83 0 83 83 0 8 0 nchpl 144 1663 0 61 60 0 60 60 0 8 0 uvmvnodes 72 1472 0 0 27 0 27 27 0 8 0 vnodes 208 1472 0 0 78 0 78 78 0 8 0 namei 1024 4070 0 4070 1 0 1 1 0 8 1 scxspl 192 4108 0 4107 1 0 1 1 0 8 0 plimitpl 152 14 0 7 1 0 1 1 0 8 0 sigapl 424 228 0 200 4 0 4 4 0 8 0 futexpl 56 211 0 211 1 0 1 1 0 8 1 knotepl 112 61 0 42 1 0 1 1 0 8 0 kqueuepl 144 2 0 0 1 0 1 1 0 8 0 pipelkpl 16 74 0 64 1 0 1 1 0 8 0 pipepl 120 148 0 129 1 0 1 1 0 8 0 fdescpl 432 214 0 200 2 0 2 2 0 8 0 filepl 120 1079 0 982 4 0 4 4 0 8 1 lockfpl 104 5 0 4 1 0 1 1 0 8 0 lockfspl 48 3 0 2 1 0 1 1 0 8 0 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 17 0 7 1 0 1 1 0 8 0 ucredpl 96 54 0 47 1 0 1 1 0 8 0 zombiepl 144 200 0 200 1 0 1 1 0 8 1 processpl 920 228 0 200 4 0 4 4 0 8 0 procpl 624 244 0 209 3 0 3 3 0 8 0 sockpl 400 110 0 92 3 0 3 3 0 8 1 mcl64k 65536 1 0 1 1 0 1 1 0 8 1 mcl4k 4096 9 0 9 2 1 1 1 0 8 1 mcl2k 2048 65006 0 64959 16 3 13 13 0 8 6 mtagpl 80 2 0 2 1 1 0 1 0 8 0 mbufpl 256 103265 0 103123 12 2 10 10 0 8 0 bufpl 280 3224 0 126 222 0 222 222 0 8 0 anonpl 16 34109 0 20958 55 2 53 53 0 107 0 amapchunkpl 152 1054 0 926 7 0 7 7 0 158 1 amappl16 192 841 0 134 36 0 36 36 0 8 0 amappl15 184 7 0 5 1 0 1 1 0 8 0 amappl14 176 22 0 18 1 0 1 1 0 8 0 amappl13 168 26 0 23 1 0 1 1 0 8 0 amappl12 160 10 0 6 1 0 1 1 0 8 0 amappl11 152 48 0 38 1 0 1 1 0 8 0 amappl10 144 10 0 7 1 0 1 1 0 8 0 amappl9 136 372 0 370 1 0 1 1 0 8 0 amappl8 128 308 0 271 2 0 2 2 0 8 0 amappl7 120 115 0 102 1 0 1 1 0 8 0 amappl6 112 22 0 19 1 0 1 1 0 8 0 amappl5 104 161 0 148 1 0 1 1 0 8 0 amappl4 96 415 0 391 1 0 1 1 0 8 0 amappl3 88 100 0 94 1 0 1 1 0 8 0 amappl2 80 879 0 815 2 0 2 2 0 8 0 amappl1 72 13496 0 13068 23 6 17 17 0 8 7 amappl 80 463 0 424 1 0 1 1 0 84 0 dma4096 4096 1 0 1 1 1 0 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 64 1 0 0 1 0 1 1 0 8 0 uaddrrnd 24 214 0 200 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 214 0 200 1 0 1 1 0 8 0 vmmpekpl 168 5740 0 5718 2 0 2 2 0 8 0 vmmpepl 168 32864 0 31078 105 5 100 100 0 357 22 vmsppl 272 213 0 200 2 0 2 2 0 8 1 pdppl 4096 434 0 400 6 0 6 6 0 8 1 pvpl 32 121401 0 105312 133 0 133 133 0 265 1 pmappl 200 213 0 200 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 236 0 8 7 0 7 7 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821d6175) at panic+0x15c sys/kern/subr_prf.c:207 malloc(1800,2,9) at malloc+0xa23 sys/kern/kern_malloc.c:331 wsevent_init(ffff800000653c50) at wsevent_init+0x49 sys/dev/wscons/wsevent.c:109 wsmouseopen(4400,1,2000,ffff80001d7394e8) at wsmouseopen+0x11e sys/dev/wscons/wsmouse.c:331 spec_open(ffff8000208429f8) at spec_open+0x3ea sys/kern/spec_vnops.c:157 VOP_OPEN(fffffd806854c4e0,1,fffffd806c3bfba0,ffff80001d7394e8) at VOP_OPEN+0x6a sys/kern/vfs_vops.c:153 vn_open(ffff800020842c48,1,0) at vn_open+0x490 sys/kern/vfs_vnops.c:183 doopenat(ffff80001d7394e8,ffffff9c,20000000,0,0,ffff800020842e40) at doopenat+0x28b sys/kern/vfs_syscalls.c:1141 syscall(ffff800020842ec0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x8503aeac100, count: -11 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821d6175) at panic+0x15c sys/kern/subr_prf.c:207 malloc(1800,2,9) at malloc+0xa23 sys/kern/kern_malloc.c:331 wsevent_init(ffff800000653c50) at wsevent_init+0x49 sys/dev/wscons/wsevent.c:109 wsmouseopen(4400,1,2000,ffff80001d7394e8) at wsmouseopen+0x11e sys/dev/wscons/wsmouse.c:331 spec_open(ffff8000208429f8) at spec_open+0x3ea sys/kern/spec_vnops.c:157 VOP_OPEN(fffffd806854c4e0,1,fffffd806c3bfba0,ffff80001d7394e8) at VOP_OPEN+0x6a sys/kern/vfs_vops.c:153 vn_open(ffff800020842c48,1,0) at vn_open+0x490 sys/kern/vfs_vnops.c:183 doopenat(ffff80001d7394e8,ffffff9c,20000000,0,0,ffff800020842e40) at doopenat+0x28b sys/kern/vfs_syscalls.c:1141 syscall(ffff800020842ec0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x8503aeac100, count: -11