panic: Data modified on freelist: word 4 of object 0xffff80000143ac00 size 0x200 previous type free (0x6563 != 0xdead4110) Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *521330 35191 0 0 0x4000000 0 syz-executor.7 db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8335b9e1) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(200,7f,1) at malloc+0xd7c sys/kern/kern_malloc.c:353 vndsetcred(ffff80002a7f1738,fffffd807d8dc570,58,ffff80002a8c52a0) at vndsetcred+0x65 sys/dev/vnd.c:680 vndioctl(2902,c0384600,ffff80002a8c5510,1,ffff80002a7f1738) at vndioctl+0xe6c sys/dev/vnd.c:485 VOP_IOCTL(fffffd806e2c1d08,c0384600,ffff80002a8c5510,1,fffffd807f7d7618,ffff80002a7f1738) at VOP_IOCTL+0xa3 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd806b765870,c0384600,ffff80002a8c5510,ffff80002a7f1738) at vn_ioctl+0xea sys/kern/vfs_vnops.c:531 sys_ioctl(ffff80002a7f1738,ffff80002a8c56f0,ffff80002a8c5640) at sys_ioctl+0x5bf syscall(ffff80002a8c56f0) at syscall+0x97e sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xeb53383b8c0, 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 0xffff80000143ac00 size 0x200 previous type free (0x6563 != 0xdead4110) ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8335b9e1) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(200,7f,1) at malloc+0xd7c sys/kern/kern_malloc.c:353 vndsetcred(ffff80002a7f1738,fffffd807d8dc570,58,ffff80002a8c52a0) at vndsetcred+0x65 sys/dev/vnd.c:680 vndioctl(2902,c0384600,ffff80002a8c5510,1,ffff80002a7f1738) at vndioctl+0xe6c sys/dev/vnd.c:485 VOP_IOCTL(fffffd806e2c1d08,c0384600,ffff80002a8c5510,1,fffffd807f7d7618,ffff80002a7f1738) at VOP_IOCTL+0xa3 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd806b765870,c0384600,ffff80002a8c5510,ffff80002a7f1738) at vn_ioctl+0xea sys/kern/vfs_vnops.c:531 sys_ioctl(ffff80002a7f1738,ffff80002a8c56f0,ffff80002a8c5640) at sys_ioctl+0x5bf syscall(ffff80002a8c56f0) at syscall+0x97e sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xeb53383b8c0, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002a8c4af0 rbx 0xffff80000143ac00 rdx 0x3fd rcx 0 rax 0x7c r8 0x101010101010101 r9 0x8080808080808080 r10 0xe6800e352abade59 r11 0xe667cc96c8bacd25 r12 0 r13 0xffffffff838dc638 bucket+0x288 r14 0 r15 0x1 rip 0xffffffff81880545 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a8c4ae0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (syz-executor.7) tid=521330 pid=35191 tcnt=2 stat=onproc flags process=0 proc=4000000 runpri=32, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a7f1218,0xffff80002a7f19d8 process=0xffff80002a88d178 user=0xffff80002a8c0000, vmspace=0xfffffd807eb93000 estcpu=0, cpticks=2, pctcpu=0.0, user=0, sys=2, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 15080 106456 20698 0 2 0 syz-executor.4 57081 518644 57516 0 2 0 syz-executor.0 35191 273534 35296 0 2 0 syz-executor.7 *35191 521330 35296 0 7 0x4000000 syz-executor.7 66330 477197 6013 0 2 0 syz-executor.6 66330 43559 6013 0 3 0x4000080 fsleep syz-executor.6 43433 310857 86091 0 2 0 syz-executor.5 43433 285621 86091 0 2 0x4000000 syz-executor.5 95665 17885 22891 0 2 0 syz-executor.2 95665 274043 22891 0 3 0x4000080 fsleep syz-executor.2 95665 349786 22891 0 3 0x4000080 fsleep syz-executor.2 18814 71303 94930 0 2 0 syz-executor.1 18814 427004 94930 0 3 0x4000080 fsleep syz-executor.1 35296 77198 37927 0 3 0x82 nanoslp syz-executor.7 20698 351431 37927 0 3 0x82 nanoslp syz-executor.4 6013 240525 37927 0 3 0x82 nanoslp syz-executor.6 86091 302718 37927 0 3 0x82 nanoslp syz-executor.5 10181 297123 37927 0 2 0x2 syz-executor.3 22891 55488 37927 0 3 0x82 nanoslp syz-executor.2 94930 425823 37927 0 3 0x82 nanoslp syz-executor.1 57516 202504 37927 0 3 0x82 nanoslp syz-executor.0 37927 151770 74855 0 3 0x82 thrsleep syz-execprog 37927 158308 74855 0 3 0x4000082 nanoslp syz-execprog 37927 460544 74855 0 3 0x4000082 wait syz-execprog 37927 308547 74855 0 3 0x4000082 wait syz-execprog 37927 475028 74855 0 3 0x4000082 thrsleep syz-execprog 37927 162282 74855 0 3 0x4000082 wait syz-execprog 37927 113429 74855 0 3 0x4000082 wait syz-execprog 37927 306830 74855 0 3 0x4000082 wait syz-execprog 37927 156471 74855 0 3 0x4000082 wait syz-execprog 37927 18096 74855 0 3 0x4000082 thrsleep syz-execprog 37927 54466 74855 0 3 0x4000082 wait syz-execprog 37927 15392 74855 0 3 0x4000082 wait syz-execprog 37927 446837 74855 0 3 0x4000082 kqread syz-execprog 74855 278445 90978 0 3 0x10008a sigsusp ksh 90978 177927 50648 0 3 0x98 kqread sshd-session 50648 209512 86351 0 3 0x92 kqread sshd-session 73800 516836 1 0 3 0x100083 ttyin getty 86351 438560 1 0 3 0x88 kqread sshd 1215 927 7962 73 3 0x1100090 kqread syslogd 7962 60231 1 0 3 0x100082 sbwait syslogd 82094 462896 1 0 3 0x100080 kqread resolvd 37268 265934 32753 77 3 0x100092 kqread dhcpleased 64227 268567 32753 77 3 0x100092 kqread dhcpleased 32753 20194 1 0 3 0x80 kqread dhcpleased 31657 2878 0 0 3 0x14200 bored smr 51573 95939 0 0 2 0x14200 zerothread 4899 440293 0 0 3 0x14200 aiodoned aiodoned 13762 290212 0 0 3 0x14200 syncer update 25373 302385 0 0 3 0x14200 cleaner cleaner 94337 5674 0 0 3 0x14200 reaper reaper 74182 16937 0 0 3 0x14200 pgdaemon pagedaemon 83194 114320 0 0 3 0x14200 bored viomb 9290 71401 0 0 3 0x40014200 acpi0 acpi0 37133 76889 0 0 3 0x14200 bored softnet3 36335 254651 0 0 3 0x14200 bored softnet2 59817 184791 0 0 3 0x14200 bored softnet1 56456 30905 0 0 3 0x14200 bored softnet0 4171 202426 0 0 3 0x14200 bored systqmp 54634 107128 0 0 3 0x14200 bored systq 40497 521035 0 0 3 0x40014200 tmoslp softclock 41618 139795 0 0 3 0x40014200 idle0 1 207686 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 10164 11039K 11052K 166960K 11248 0 pcb 17 12K 12K 166960K 17 0 rtable 234 6K 6K 166960K 382 0 pf 30 12K 12K 166960K 33 0 ifaddr 42 7K 7K 166960K 48 0 ifgroup 50 2K 2K 166960K 55 0 sysctl 1 1K 1K 166960K 1 0 counters 30 17K 17K 166960K 31 0 ioctlops 0 0K 2K 166960K 30 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1260 79K 79K 166960K 1277 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 1K 166960K 2 0 VM map 2 1K 1K 166960K 2 0 sem 2 0K 0K 166960K 2 0 dirhash 12 2K 2K 166960K 12 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 17 61K 73K 166960K 159 0 proc 57 58K 75K 166960K 500 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 in_multi 99 7K 7K 166960K 110 0 ether_multi 1 0K 0K 166960K 1 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 25 122K 122K 166960K 25 0 exec 0 0K 1K 166960K 418 0 fusefs mount 1 32K 32K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 245 152K 206K 166960K 4260 0 UVM aobj 3 2K 2K 166960K 3 0 pinsyscall 39 78K 104K 166960K 1515 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 NDP 27 2K 2K 166960K 30 0 temp 1 8664K 8728K 166960K 4714 0 kqueue 13 20K 20K 166960K 46 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 39 0 36 1 0 1 1 0 8 0 rtentry 136 122 0 12 4 0 4 4 0 8 0 unpcb 144 67 0 52 1 0 1 1 0 8 0 syncache 336 9 0 9 1 0 1 1 0 8 1 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 344 66 0 60 1 0 1 1 0 8 0 nd6 104 27 0 3 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 501 0 48 29 0 29 29 0 8 0 art_table 32 502 0 48 4 0 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 1620 0 98 96 0 96 96 0 8 0 ffsino 248 1620 0 98 96 0 96 96 0 8 0 nchpl 144 1917 0 135 67 0 67 67 0 8 0 uvmvnodes 80 1630 0 0 34 0 34 34 0 8 0 vnodes 216 1630 0 0 91 0 91 91 0 8 0 namei 1024 7676 0 7676 2 0 2 2 0 8 2 kstatmem 264 24 0 2 2 0 2 2 0 8 0 scxspl 216 9378 0 9337 8 0 8 8 1 8 5 plimitpl 152 58 0 42 1 0 1 1 0 8 0 sigapl 424 501 0 456 6 0 6 6 0 8 0 futexpl 64 62 0 58 1 0 1 1 0 8 0 knotepl 120 6945 0 6866 4 0 4 4 0 8 0 kqueuepl 184 42 0 33 1 0 1 1 0 8 0 pipepl 296 184 0 156 3 0 3 3 0 8 0 fdescpl 440 485 0 456 4 0 4 4 0 8 0 filepl 120 2145 0 2006 5 0 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 34 0 18 1 0 1 1 0 8 0 pgrppl 48 34 0 18 1 0 1 1 0 8 0 ucredpl 104 151 0 139 1 0 1 1 0 8 0 zombiepl 144 456 0 456 1 0 1 1 0 8 1 processpl 1112 501 0 456 4 0 4 4 0 8 0 procpl 656 535 0 472 6 0 6 6 0 8 0 sockpl 528 172 0 148 2 0 2 2 0 8 0 mcl8k 8192 13 0 13 1 0 1 1 0 8 1 mcl4k 4096 8420 0 8364 15 0 15 15 0 8 7 mcl2k 2048 153 0 153 1 0 1 1 0 8 1 mtagpl 96 4 0 4 1 0 1 1 0 8 1 mbufpl 256 11860 0 11716 10 0 10 10 0 8 1 bufpl 280 4857 0 209 332 0 332 332 0 8 0 anonpl 24 207687 0 203411 54 0 54 54 0 187 25 amapchunkpl 152 13358 0 12809 27 0 27 27 0 158 5 amappl16 200 4420 0 4323 7 0 7 7 0 8 1 amappl15 192 16 0 14 1 0 1 1 0 8 0 amappl14 184 244 0 231 2 0 2 2 0 8 1 amappl13 176 12 0 12 1 0 1 1 0 8 1 amappl12 168 1176 0 1145 2 0 2 2 0 8 0 amappl11 160 52 0 42 1 0 1 1 0 8 0 amappl10 152 82 0 72 1 0 1 1 0 8 0 amappl9 144 915 0 915 1 0 1 1 0 8 1 amappl8 136 155 0 131 1 0 1 1 0 8 0 amappl7 128 223 0 210 2 0 2 2 0 8 0 amappl6 120 320 0 314 2 0 2 2 0 8 1 amappl5 112 168 0 162 1 0 1 1 0 8 0 amappl4 104 514 0 495 2 0 2 2 0 8 1 amappl3 96 1464 0 1383 3 0 3 3 0 8 0 amappl2 88 1070 0 1001 4 0 4 4 0 8 1 amappl1 80 16190 0 15621 27 7 20 23 0 8 7 amappl 88 3138 0 2980 4 0 4 4 0 92 0 dma4096 4096 1 0 1 1 0 1 1 0 8 1 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 6 0 6 1 0 1 1 0 8 1 dma128 128 253 0 253 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 18 0 17 1 0 1 1 0 8 0 aobjpl 72 2 0 0 1 0 1 1 0 8 0 uaddrrnd 24 485 0 456 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 485 0 456 1 0 1 1 0 8 0 vmmpekpl 168 11702 0 11661 2 0 2 2 0 8 0 vmmpepl 168 61944 0 60075 121 0 121 121 0 357 38 vmsppl 360 484 0 456 3 0 3 3 0 8 0 rwobjpl 32 25503 0 22939 27 0 27 27 0 8 2 pdppl 4096 976 0 912 112 42 70 70 0 8 6 pvpl 32 550036 0 540376 395 100 295 395 0 265 214 pmappl 216 484 0 456 2 0 2 2 0 8 0 extentpl 40 55 0 38 1 0 1 1 0 8 0 phpool 112 275 0 42 7 0 7 7 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8335b9e1) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(200,7f,1) at malloc+0xd7c sys/kern/kern_malloc.c:353 vndsetcred(ffff80002a7f1738,fffffd807d8dc570,58,ffff80002a8c52a0) at vndsetcred+0x65 sys/dev/vnd.c:680 vndioctl(2902,c0384600,ffff80002a8c5510,1,ffff80002a7f1738) at vndioctl+0xe6c sys/dev/vnd.c:485 VOP_IOCTL(fffffd806e2c1d08,c0384600,ffff80002a8c5510,1,fffffd807f7d7618,ffff80002a7f1738) at VOP_IOCTL+0xa3 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd806b765870,c0384600,ffff80002a8c5510,ffff80002a7f1738) at vn_ioctl+0xea sys/kern/vfs_vnops.c:531 sys_ioctl(ffff80002a7f1738,ffff80002a8c56f0,ffff80002a8c5640) at sys_ioctl+0x5bf syscall(ffff80002a8c56f0) at syscall+0x97e sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xeb53383b8c0, count: -10 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8335b9e1) at panic+0x1cf sys/kern/subr_prf.c:198 malloc(200,7f,1) at malloc+0xd7c sys/kern/kern_malloc.c:353 vndsetcred(ffff80002a7f1738,fffffd807d8dc570,58,ffff80002a8c52a0) at vndsetcred+0x65 sys/dev/vnd.c:680 vndioctl(2902,c0384600,ffff80002a8c5510,1,ffff80002a7f1738) at vndioctl+0xe6c sys/dev/vnd.c:485 VOP_IOCTL(fffffd806e2c1d08,c0384600,ffff80002a8c5510,1,fffffd807f7d7618,ffff80002a7f1738) at VOP_IOCTL+0xa3 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd806b765870,c0384600,ffff80002a8c5510,ffff80002a7f1738) at vn_ioctl+0xea sys/kern/vfs_vnops.c:531 sys_ioctl(ffff80002a7f1738,ffff80002a8c56f0,ffff80002a8c5640) at sys_ioctl+0x5bf syscall(ffff80002a8c56f0) at syscall+0x97e sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xeb53383b8c0, count: -10