panic: Data modified on freelist: word 4 of object 0xffff800000cd5600 size 0x194 previous type free (0x6563 != 0xdeafbead) Stopped at db_enter+0x1c: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *254225 78764 0 0 0x4000000 0 syz-executor.3 db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82778034) at panic+0x165 sys/kern/subr_prf.c:198 malloc(194,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:362 disk_attach(ffff8000006b5000,ffff8000006b5048) at disk_attach+0x8e sys/kern/subr_disk.c:1082 vndioctl(2902,c0384600,ffff800021839ae0,1,ffff8000ffff15f0) at vndioctl+0xeb6 sys/dev/vnd.c:539 VOP_IOCTL(fffffd8079d4dd08,c0384600,ffff800021839ae0,1,fffffd807f7d7618,ffff8000ffff15f0) at VOP_IOCTL+0x91 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd807550b9e0,c0384600,ffff800021839ae0,ffff8000ffff15f0) at vn_ioctl+0xbb sys/kern/vfs_vnops.c:525 sys_ioctl(ffff8000ffff15f0,ffff800021839bf0,ffff800021839c40) at sys_ioctl+0x49e syscall(ffff800021839cc0) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x3d817aad2a0, count: 5 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 0xffff800000cd5600 size 0x194 previous type free (0x6563 != 0xdeafbead) ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82778034) at panic+0x165 sys/kern/subr_prf.c:198 malloc(194,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:362 disk_attach(ffff8000006b5000,ffff8000006b5048) at disk_attach+0x8e sys/kern/subr_disk.c:1082 vndioctl(2902,c0384600,ffff800021839ae0,1,ffff8000ffff15f0) at vndioctl+0xeb6 sys/dev/vnd.c:539 VOP_IOCTL(fffffd8079d4dd08,c0384600,ffff800021839ae0,1,fffffd807f7d7618,ffff8000ffff15f0) at VOP_IOCTL+0x91 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd807550b9e0,c0384600,ffff800021839ae0,ffff8000ffff15f0) at vn_ioctl+0xbb sys/kern/vfs_vnops.c:525 sys_ioctl(ffff8000ffff15f0,ffff800021839bf0,ffff800021839c40) at sys_ioctl+0x49e syscall(ffff800021839cc0) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x3d817aad2a0, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff8000218390c0 rbx 0xffff800000cd5600 rdx 0 rcx 0 rax 0xffff8000ffff15f0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xc22f54bb932cdcbb r11 0x91b6aa9a4e190828 r12 0 r13 0x51 r14 0 r15 0x1 rip 0xffffffff81aeb73c db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff8000218390b0 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb> show proc PROC (syz-executor.3) pid=254225 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=52, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffff1338,0xffffffff82ceddc0 process=0xffff8000fffefb98 user=0xffff800021834000, vmspace=0xfffffd80790bacf8 estcpu=8, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 86698 476747 39454 0 2 0 syz-executor.5 86698 447880 39454 0 3 0x4000080 fsleep syz-executor.5 53511 387237 25128 0 2 0 syz-executor.2 53511 462551 25128 0 2 0x4000000 syz-executor.2 78764 417165 68369 0 2 0 syz-executor.3 *78764 254225 68369 0 7 0x4000000 syz-executor.3 15271 335107 91220 0 3 0x82 nanoslp syz-executor.6 2676 174817 91220 0 3 0x2 biowait syz-executor.7 68369 371185 91220 0 3 0x82 nanoslp syz-executor.3 25128 386182 91220 0 3 0x82 nanoslp syz-executor.2 39454 421713 91220 0 3 0x82 nanoslp syz-executor.5 99331 79851 91220 0 2 0x2 syz-executor.4 81994 433327 91220 0 3 0x2 biowait syz-executor.1 71860 6167 91220 0 3 0x2 biowait syz-executor.0 91220 80062 12999 0 3 0x2000082 thrsleep syz-execprog 91220 501226 12999 0 3 0x6000082 nanoslp syz-execprog 91220 406181 12999 0 3 0x6000082 wait syz-execprog 91220 108198 12999 0 3 0x6000082 wait syz-execprog 91220 372334 12999 0 3 0x6000082 wait syz-execprog 91220 200552 12999 0 3 0x6000082 wait syz-execprog 91220 162781 12999 0 3 0x6000082 wait syz-execprog 91220 72314 12999 0 3 0x6000082 thrsleep syz-execprog 91220 521327 12999 0 3 0x6000082 wait syz-execprog 91220 427976 12999 0 3 0x6000082 thrsleep syz-execprog 91220 507575 12999 0 3 0x6000082 wait syz-execprog 91220 410125 12999 0 3 0x6000082 wait syz-execprog 91220 292101 12999 0 3 0x6000082 kqread syz-execprog 12999 440458 49120 0 3 0x10008a sigsusp ksh 49120 167948 26056 0 3 0x9a kqread sshd 83278 442226 1 0 3 0x100083 ttyin getty 26056 155562 1 0 3 0x88 kqread sshd 13349 323199 99168 73 3 0x1100090 kqread syslogd 99168 251610 1 0 3 0x100082 netio syslogd 87070 189814 1 0 3 0x100080 kqread resolvd 85828 266403 13580 77 3 0x100092 kqread dhcpleased 76361 18680 13580 77 3 0x100092 kqread dhcpleased 13580 204327 1 0 3 0x80 kqread dhcpleased 57908 395392 0 0 3 0x14200 bored smr 59852 507918 0 0 2 0x14200 zerothread 30713 439768 0 0 3 0x14200 aiodoned aiodoned 44223 295015 0 0 3 0x14200 syncer update 85049 161449 0 0 3 0x14200 cleaner cleaner 68205 228392 0 0 3 0x14200 reaper reaper 60568 234959 0 0 3 0x14200 pgdaemon pagedaemon 37092 61621 0 0 3 0x14200 bored viomb 7356 413501 0 0 3 0x40014200 acpi0 acpi0 75549 256940 0 0 3 0x14200 bored softnet3 89062 471853 0 0 3 0x14200 bored softnet2 47566 352913 0 0 3 0x14200 bored softnet1 88722 315057 0 0 3 0x14200 bored softnet0 25146 17939 0 0 3 0x14200 bored systqmp 68575 251260 0 0 3 0x14200 bored systq 47709 523773 0 0 3 0x40014200 bored softclock 68366 372586 0 0 3 0x40014200 idle0 1 310192 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 10163 6401K 6413K 78643K 11276 0 pcb 13 8K 8K 78643K 13 0 rtable 234 6K 6K 78643K 380 0 pf 29 8K 8K 78643K 32 0 ifaddr 43 11K 11K 78643K 49 0 ifgroup 50 2K 2K 78643K 55 0 counters 28 17K 17K 78643K 29 0 ioctlops 0 0K 2K 78643K 30 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1187 74K 74K 78643K 1201 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 1K 1K 78643K 2 0 sem 2 0K 0K 78643K 2 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 13 45K 69K 78643K 224 0 proc 55 58K 75K 78643K 498 0 subproc 0 0K 0K 78643K 13 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 99 7K 7K 78643K 110 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 25 122K 122K 78643K 25 0 exec 0 0K 1K 78643K 404 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 218 73K 74K 78643K 4807 0 UVM aobj 3 2K 2K 78643K 3 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 11 0K 2K 78643K 30 0 temp 1 5896K 5960K 78643K 4805 0 kqueue 12 18K 18K 78643K 34 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 38 0 35 1 0 1 1 0 8 0 rtentry 112 122 0 12 4 0 4 4 0 8 0 unpcb 144 45 0 32 1 0 1 1 0 8 0 syncache 296 8 0 8 2 1 1 1 0 8 1 tcpqe 32 165 0 165 2 2 0 1 0 8 0 tcpcb 808 12 0 9 1 0 1 1 0 8 0 arp 88 20 0 2 1 0 1 1 0 8 0 inpcb 336 66 0 60 1 0 1 1 0 8 0 nd6 104 27 0 3 2 1 1 1 0 8 0 kcovpl 48 1 0 1 1 1 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 501 0 48 32 3 29 29 0 8 0 art_table 32 502 0 48 5 1 4 4 0 8 0 art_node 16 121 0 21 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1660 0 215 92 1 91 91 0 8 0 ffsino 240 1660 0 215 86 0 86 86 0 8 0 nchpl 144 2085 0 394 63 0 63 63 0 8 0 uvmvnodes 80 1683 0 0 35 0 35 35 0 8 0 vnodes 216 1683 0 0 94 0 94 94 0 8 0 namei 1024 7821 0 7819 4 3 1 3 0 8 0 kstatmem 264 24 0 2 2 0 2 2 0 8 0 scxspl 216 13222 0 13219 14 6 8 8 1 8 7 plimitpl 152 49 0 34 1 0 1 1 0 8 0 sigapl 424 551 0 510 7 1 6 6 0 8 1 futexpl 64 595 0 594 2 1 1 1 0 8 0 knotepl 120 6654 0 6576 3 0 3 3 0 8 0 kqueuepl 184 30 0 22 1 0 1 1 0 8 0 pipepl 288 182 0 154 4 1 3 3 0 8 1 fdescpl 432 535 0 511 5 1 4 4 0 8 1 filepl 120 2233 0 2097 6 1 5 5 0 8 0 lockfpl 104 6 0 4 1 0 1 1 0 8 0 lockfspl 48 4 0 2 1 0 1 1 0 8 0 sessionpl 144 32 0 16 1 0 1 1 0 8 0 pgrppl 48 32 0 16 1 0 1 1 0 8 0 ucredpl 104 126 0 115 1 0 1 1 0 8 0 zombiepl 144 511 0 510 2 1 1 1 0 8 0 processpl 1008 551 0 510 9 3 6 6 0 8 0 procpl 696 659 0 603 10 3 7 7 0 8 1 sockpl 456 149 0 127 4 0 4 4 0 8 1 mcl8k 8192 12 0 12 2 1 1 1 0 8 1 mcl4k 4096 8 0 8 2 1 1 1 0 8 1 mcl2k 2048 22412 0 22364 58 45 13 32 0 8 6 mtagpl 96 4 0 4 1 1 0 1 0 8 0 mbufpl 256 36099 0 35953 29 19 10 17 0 8 0 bufpl 288 10099 0 3701 458 0 458 458 0 8 0 anonpl 24 433792 0 428939 55 15 40 55 0 188 8 amapchunkpl 152 19924 0 19397 39 13 26 27 0 158 4 amappl16 200 13585 0 13467 15 5 10 10 0 8 3 amappl15 192 39 0 38 1 0 1 1 0 8 0 amappl14 184 221 0 208 3 1 2 2 0 8 0 amappl13 176 28 0 27 2 1 1 1 0 8 0 amappl12 168 1220 0 1196 3 1 2 2 0 8 0 amappl11 160 69 0 59 1 0 1 1 0 8 0 amappl10 152 52 0 42 1 0 1 1 0 8 0 amappl9 144 290 0 290 2 1 1 1 0 8 1 amappl8 136 217 0 191 2 1 1 2 0 8 0 amappl7 128 142 0 136 2 1 1 2 0 8 0 amappl6 120 280 0 261 2 1 1 2 0 8 0 amappl5 112 224 0 216 1 0 1 1 0 8 0 amappl4 104 722 0 687 4 2 2 3 0 8 0 amappl3 96 4679 0 4613 4 1 3 3 0 8 1 amappl2 88 935 0 878 5 2 3 3 0 8 0 amappl1 80 15088 0 14589 29 11 18 22 0 8 6 amappl 88 4156 0 4007 7 2 5 5 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 2 0 0 1 0 1 1 0 8 0 uaddrrnd 24 535 0 511 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 535 0 511 1 0 1 1 0 8 0 vmmpekpl 168 14249 0 14230 2 0 2 2 0 8 0 vmmpepl 168 74289 0 72732 112 13 99 112 0 357 27 vmsppl 368 534 0 511 4 1 3 3 0 8 0 rwobjpl 24 37272 0 34602 20 2 18 20 0 8 0 pdppl 4096 1077 0 1022 111 46 65 67 0 8 10 pvpl 32 754964 0 745439 358 70 288 358 0 265 206 pmappl 216 534 0 511 3 1 2 2 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 891 0 123 23 0 23 23 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(ffffffff82778034) at panic+0x165 sys/kern/subr_prf.c:198 malloc(194,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:362 disk_attach(ffff8000006b5000,ffff8000006b5048) at disk_attach+0x8e sys/kern/subr_disk.c:1082 vndioctl(2902,c0384600,ffff800021839ae0,1,ffff8000ffff15f0) at vndioctl+0xeb6 sys/dev/vnd.c:539 VOP_IOCTL(fffffd8079d4dd08,c0384600,ffff800021839ae0,1,fffffd807f7d7618,ffff8000ffff15f0) at VOP_IOCTL+0x91 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd807550b9e0,c0384600,ffff800021839ae0,ffff8000ffff15f0) at vn_ioctl+0xbb sys/kern/vfs_vnops.c:525 sys_ioctl(ffff8000ffff15f0,ffff800021839bf0,ffff800021839c40) at sys_ioctl+0x49e syscall(ffff800021839cc0) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x3d817aad2a0, count: -10 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82778034) at panic+0x165 sys/kern/subr_prf.c:198 malloc(194,2,a) at malloc+0xa85 sys/kern/kern_malloc.c:362 disk_attach(ffff8000006b5000,ffff8000006b5048) at disk_attach+0x8e sys/kern/subr_disk.c:1082 vndioctl(2902,c0384600,ffff800021839ae0,1,ffff8000ffff15f0) at vndioctl+0xeb6 sys/dev/vnd.c:539 VOP_IOCTL(fffffd8079d4dd08,c0384600,ffff800021839ae0,1,fffffd807f7d7618,ffff8000ffff15f0) at VOP_IOCTL+0x91 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd807550b9e0,c0384600,ffff800021839ae0,ffff8000ffff15f0) at vn_ioctl+0xbb sys/kern/vfs_vnops.c:525 sys_ioctl(ffff8000ffff15f0,ffff800021839bf0,ffff800021839c40) at sys_ioctl+0x49e syscall(ffff800021839cc0) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x3d817aad2a0, count: -10