panic: Data modified on freelist: word 4 of object 0xffff800000cc8c00 size 0x194 previous type free (0x6563 != 0xdeadbeef) Stopped at db_enter+0x1c: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *416028 48250 0 0 0 0 syz-executor2850578658 db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8277078e) 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,ffff8000216f4150,1,ffff8000ffff2db8) at vndioctl+0xeb6 sys/dev/vnd.c:539 VOP_IOCTL(fffffd806ede1eb8,c0384600,ffff8000216f4150,1,fffffd807f7d77b8,ffff8000ffff2db8) at VOP_IOCTL+0x91 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd806f89af00,c0384600,ffff8000216f4150,ffff8000ffff2db8) at vn_ioctl+0xbb sys/kern/vfs_vnops.c:525 sys_ioctl(ffff8000ffff2db8,ffff8000216f4260,ffff8000216f42b0) at sys_ioctl+0x49e syscall(ffff8000216f4330) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7d2a35df6d40, 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 0xffff800000cc8c00 size 0x194 previous type free (0x6563 != 0xdeadbeef) ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8277078e) 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,ffff8000216f4150,1,ffff8000ffff2db8) at vndioctl+0xeb6 sys/dev/vnd.c:539 VOP_IOCTL(fffffd806ede1eb8,c0384600,ffff8000216f4150,1,fffffd807f7d77b8,ffff8000ffff2db8) at VOP_IOCTL+0x91 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd806f89af00,c0384600,ffff8000216f4150,ffff8000ffff2db8) at vn_ioctl+0xbb sys/kern/vfs_vnops.c:525 sys_ioctl(ffff8000ffff2db8,ffff8000216f4260,ffff8000216f42b0) at sys_ioctl+0x49e syscall(ffff8000216f4330) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7d2a35df6d40, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff8000216f3730 rbx 0xffff800000cc8c00 rdx 0x3fd rcx 0 rax 0x7c r8 0x101010101010101 r9 0x8080808080808080 r10 0xf3a5b7cd13330902 r11 0x241d597687c0be36 r12 0 r13 0x51 r14 0 r15 0x1 rip 0xffffffff8162a3fc db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff8000216f3720 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb> show proc PROC (syz-executor2850578658) pid=416028 stat=onproc flags process=0 proc=0 pri=51, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffff3070,0xffff8000ffff2b10 process=0xffff8000ffff0000 user=0xffff8000216ef000, vmspace=0xfffffd806c4ff740 estcpu=2, cpticks=2, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 59715 353826 9277 0 3 0 biowait syz-executor2850578658 74739 305723 66721 0 3 0 biowait syz-executor2850578658 *48250 416028 39420 0 7 0 syz-executor2850578658 82911 266861 82839 0 3 0x80 nanoslp syz-executor2850578658 18738 468578 82839 0 3 0 biowait syz-executor2850578658 39420 445428 82839 0 3 0x80 nanoslp syz-executor2850578658 31976 485573 82839 0 3 0 getblk syz-executor2850578658 66472 450083 82839 0 3 0 getblk syz-executor2850578658 66721 96257 82839 0 3 0x80 nanoslp syz-executor2850578658 96910 67381 82839 0 3 0 getblk syz-executor2850578658 9277 124124 82839 0 3 0x80 nanoslp syz-executor2850578658 82839 306711 77128 0 3 0x82 nanoslp syz-executor2850578658 77128 109598 24205 0 3 0x10008a sigsusp ksh 24205 142820 67500 0 3 0x9a kqread sshd 1559 30100 1 0 3 0x100083 ttyin getty 67500 340612 1 0 3 0x88 kqread sshd 36769 240094 93725 73 3 0x1100090 kqread syslogd 93725 57840 1 0 3 0x100082 netio syslogd 97807 515231 1 0 3 0x100080 kqread resolvd 1482 36110 6684 77 3 0x100092 kqread dhcpleased 91784 295896 6684 77 3 0x100092 kqread dhcpleased 6684 303770 1 0 3 0x80 kqread dhcpleased 63590 147435 0 0 3 0x14200 bored smr 8828 357404 0 0 2 0x14200 zerothread 12171 505880 0 0 3 0x14200 aiodoned aiodoned 60183 291702 0 0 3 0x14200 syncer update 97966 493393 0 0 3 0x14200 cleaner cleaner 17030 290903 0 0 3 0x14200 reaper reaper 71299 207533 0 0 3 0x14200 pgdaemon pagedaemon 13991 79174 0 0 3 0x14200 bored viomb 74055 232697 0 0 3 0x40014200 acpi0 acpi0 95827 455559 0 0 3 0x14200 bored softnet3 88594 147395 0 0 3 0x14200 bored softnet2 85658 276053 0 0 3 0x14200 bored softnet1 97591 117395 0 0 3 0x14200 bored softnet0 18087 484541 0 0 3 0x14200 bored systqmp 52884 381598 0 0 3 0x14200 bored systq 47554 120322 0 0 3 0x40014200 bored softclock 94510 89207 0 0 3 0x40014200 idle0 1 290386 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 10133 6382K 6412K 78643K 11215 0 pcb 13 8K 8K 78643K 13 0 rtable 58 1K 2K 78643K 110 0 pf 12 6K 6K 78643K 12 0 ifaddr 11 5K 5K 78643K 11 0 ifgroup 17 1K 1K 78643K 17 0 counters 20 16K 16K 78643K 20 0 ioctlops 0 0K 2K 78643K 21 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1174 73K 74K 78643K 1188 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 1 0K 0K 78643K 1 0 proc 55 58K 59K 78643K 246 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 11 0K 0K 78643K 11 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 243 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 128 69K 69K 78643K 2185 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 3 0K 0K 78643K 3 0 temp 1 5844K 5908K 78643K 2761 0 kqueue 11 16K 18K 78643K 24 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 20 0 17 1 0 1 1 0 8 0 rtentry 112 23 0 1 1 0 1 1 0 8 0 unpcb 144 33 0 20 1 0 1 1 0 8 0 syncache 296 5 0 5 2 1 1 1 0 8 1 tcpqe 32 61 0 61 1 1 0 1 0 8 0 tcpcb 808 8 0 5 1 0 1 1 0 8 0 arp 88 2 0 0 1 0 1 1 0 8 0 inpcb 336 26 0 20 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 97 0 0 7 0 7 7 0 8 0 art_table 32 98 0 0 1 0 1 1 0 8 0 art_node 16 22 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1456 0 52 88 0 88 88 0 8 0 ffsino 240 1457 0 52 83 0 83 83 0 8 0 nchpl 144 1664 0 87 59 0 59 59 0 8 0 uvmvnodes 80 1467 0 0 30 0 30 30 0 8 0 vnodes 216 1467 0 0 82 0 82 82 0 8 0 namei 1024 4372 0 4370 3 1 2 2 0 8 1 kstatmem 264 6 0 0 1 0 1 1 0 8 0 scxspl 216 5708 0 5649 25 18 7 8 0 8 3 plimitpl 152 24 0 10 1 0 1 1 0 8 0 sigapl 424 329 0 288 5 0 5 5 0 8 0 knotepl 120 3377 0 3348 3 1 2 2 0 8 1 kqueuepl 184 20 0 13 1 0 1 1 0 8 0 pipepl 288 87 0 84 2 1 1 1 0 8 0 fdescpl 432 313 0 289 3 0 3 3 0 8 0 filepl 120 1160 0 1101 2 0 2 2 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 25 0 9 1 0 1 1 0 8 0 pgrppl 48 25 0 9 1 0 1 1 0 8 0 ucredpl 104 71 0 60 1 0 1 1 0 8 0 zombiepl 144 289 0 288 2 1 1 1 0 8 0 processpl 1008 329 0 288 7 1 6 6 0 8 0 procpl 696 329 0 288 5 1 4 4 0 8 0 sockpl 456 79 0 57 3 0 3 3 0 8 0 mcl8k 8192 9 0 9 2 1 1 1 0 8 1 mcl4k 4096 5 0 5 2 1 1 1 0 8 1 mcl2k 2048 10799 0 10761 34 24 10 30 0 8 4 mtagpl 96 4 0 4 1 1 0 1 0 8 0 mbufpl 256 17386 0 17344 17 11 6 17 0 8 0 bufpl 288 3155 0 92 219 0 219 219 0 8 0 anonpl 24 173333 0 171070 28 11 17 23 0 188 1 amapchunkpl 152 8142 0 7936 9 1 8 8 0 158 0 amappl16 200 5098 0 5068 8 5 3 5 0 8 0 amappl15 192 14 0 14 1 1 0 1 0 8 0 amappl14 184 127 0 118 1 0 1 1 0 8 0 amappl13 176 22 0 22 1 1 0 1 0 8 0 amappl12 168 801 0 781 1 0 1 1 0 8 0 amappl11 160 53 0 43 1 0 1 1 0 8 0 amappl10 152 27 0 27 2 1 1 1 0 8 1 amappl9 144 125 0 125 1 1 0 1 0 8 0 amappl8 136 44 0 42 1 0 1 1 0 8 0 amappl7 128 32 0 27 1 0 1 1 0 8 0 amappl6 120 151 0 140 1 0 1 1 0 8 0 amappl5 112 81 0 74 1 0 1 1 0 8 0 amappl4 104 455 0 418 2 0 2 2 0 8 1 amappl3 96 2223 0 2178 2 0 2 2 0 8 0 amappl2 88 464 0 422 2 1 1 2 0 8 0 amappl1 80 9018 0 8570 14 3 11 11 0 8 0 amappl 88 1907 0 1824 2 0 2 2 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 24 313 0 289 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 313 0 289 1 0 1 1 0 8 0 vmmpekpl 168 6912 0 6897 1 0 1 1 0 8 0 vmmpepl 168 33791 0 32589 58 3 55 55 0 357 0 vmsppl 368 312 0 289 3 0 3 3 0 8 0 rwobjpl 24 18520 0 16363 15 1 14 14 0 8 0 pdppl 4096 633 0 578 81 22 59 59 0 8 4 pvpl 32 267435 0 262493 59 15 44 51 0 265 1 pmappl 216 312 0 289 2 0 2 2 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 550 0 63 14 0 14 14 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(ffffffff8277078e) 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,ffff8000216f4150,1,ffff8000ffff2db8) at vndioctl+0xeb6 sys/dev/vnd.c:539 VOP_IOCTL(fffffd806ede1eb8,c0384600,ffff8000216f4150,1,fffffd807f7d77b8,ffff8000ffff2db8) at VOP_IOCTL+0x91 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd806f89af00,c0384600,ffff8000216f4150,ffff8000ffff2db8) at vn_ioctl+0xbb sys/kern/vfs_vnops.c:525 sys_ioctl(ffff8000ffff2db8,ffff8000216f4260,ffff8000216f42b0) at sys_ioctl+0x49e syscall(ffff8000216f4330) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7d2a35df6d40, 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(ffffffff8277078e) 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,ffff8000216f4150,1,ffff8000ffff2db8) at vndioctl+0xeb6 sys/dev/vnd.c:539 VOP_IOCTL(fffffd806ede1eb8,c0384600,ffff8000216f4150,1,fffffd807f7d77b8,ffff8000ffff2db8) at VOP_IOCTL+0x91 sys/kern/vfs_vops.c:264 vn_ioctl(fffffd806f89af00,c0384600,ffff8000216f4150,ffff8000ffff2db8) at vn_ioctl+0xbb sys/kern/vfs_vnops.c:525 sys_ioctl(ffff8000ffff2db8,ffff8000216f4260,ffff8000216f42b0) at sys_ioctl+0x49e syscall(ffff8000216f4330) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7d2a35df6d40, count: -10