panic: witness_warn Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *442055 22667 0 0 0x4000000 0 syz-executor1 342009 34674 73 0x100010 0 1K syslogd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 witness_warn(50b1850c481dd0a7,0,ffff800020b92720) at witness_warn+0x700 witness_debugger sys/kern/subr_witness.c:2549 [inline] witness_warn(50b1850c481dd0a7,0,ffff800020b92720) at witness_warn+0x700 sys/kern/subr_witness.c:1465 userret(b28ee66bab6a7b30) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(519d818bb5524f9b) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(519d818bb5524f9b) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,0,ffffffffffffff27,0,1,83a5abba1a0) at Xsyscall+0x128 end of kernel end trace frame: 0x83c68bf0660, count: 9 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{0}> ddb{0}> set $lines = 0 ddb{0}> show panic witness_warn ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 witness_warn(50b1850c481dd0a7,0,ffff800020b92720) at witness_warn+0x700 witness_debugger sys/kern/subr_witness.c:2549 [inline] witness_warn(50b1850c481dd0a7,0,ffff800020b92720) at witness_warn+0x700 sys/kern/subr_witness.c:1465 userret(b28ee66bab6a7b30) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(519d818bb5524f9b) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(519d818bb5524f9b) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,0,ffffffffffffff27,0,1,83a5abba1a0) at Xsyscall+0x128 end of kernel end trace frame: 0x83c68bf0660, count: -6 ddb{0}> show registers rdi 0xffffffff8137f4d7 db_enter+0x17 rsi 0x4a76 __ALIGN_SIZE+0x3a76 rbp 0xffff800020c8ed40 rbx 0xffff800020c8ede0 rdx 0x4a77 __ALIGN_SIZE+0x3a77 rcx 0xffff800002f48000 rax 0xffff800002f48000 r8 0xffffffff81949104 kprintf+0x174 r9 0x1 r10 0x40f89d7b53a89a2c r11 0xae627e7434b8deaf r12 0x3000000008 r13 0xffff800020c8ed50 r14 0x100 r15 0x1 rip 0xffffffff8137f4d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c8ed30 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor1) pid=442055 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=75, nice=20 forw=0xffffffffffffffff, list=0xffff800020b924c8,0xffff800020b93090 process=0xffff800020b94358 user=0xffff800020c8a000, vmspace=0xfffffd807f00d9d8 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 81153 60787 59678 0 2 0 syz-executor0 22667 164264 59860 0 2 0 syz-executor1 22667 158614 59860 0 2 0x4000000 syz-executor1 22667 131798 59860 0 3 0x4000080 fsleep syz-executor1 *22667 442055 59860 0 7 0x4000000 syz-executor1 42251 126813 1 0 3 0x100083 ttyin getty 17575 45313 0 0 3 0x14200 bored sosplice 59860 448179 54140 0 2 0x482 syz-executor1 59678 130183 54140 0 2 0x482 syz-executor0 54140 400318 12264 0 3 0x82 kqread syz-fuzzer 54140 939 12264 0 3 0x4000082 thrsleep syz-fuzzer 54140 256049 12264 0 3 0x4000082 thrsleep syz-fuzzer 54140 503924 12264 0 3 0x4000082 thrsleep syz-fuzzer 54140 157797 12264 0 3 0x4000082 thrsleep syz-fuzzer 54140 425345 12264 0 3 0x4000082 thrsleep syz-fuzzer 54140 204128 12264 0 3 0x4000082 thrsleep syz-fuzzer 54140 314992 12264 0 3 0x4000082 thrsleep syz-fuzzer 54140 216968 12264 0 3 0x4000082 thrsleep syz-fuzzer 54140 388369 12264 0 2 0x4000482 syz-fuzzer 12264 143381 64769 0 3 0x10008a pause ksh 64769 388223 82270 0 3 0x92 select sshd 82270 478375 1 0 3 0x80 select sshd 34674 342009 66321 73 7 0x100010 syslogd 66321 161962 1 0 3 0x100082 netio syslogd 218 393707 1 77 3 0x100090 poll dhclient 6128 54945 1 0 3 0x80 poll dhclient 55810 110201 0 0 3 0x14200 pgzero zerothread 68461 418686 0 0 3 0x14200 aiodoned aiodoned 79079 393106 0 0 3 0x14200 syncer update 12449 332442 0 0 3 0x14200 cleaner cleaner 61275 209670 0 0 3 0x14200 reaper reaper 59504 363027 0 0 3 0x14200 pgdaemon pagedaemon 56953 362112 0 0 3 0x14200 bored crynlk 53300 241374 0 0 3 0x14200 bored crypto 20530 58885 0 0 3 0x40014200 acpi0 acpi0 69818 523470 0 0 3 0x40014200 idle1 79687 177665 0 0 3 0x14200 bored softnet 99998 217605 0 0 3 0x14200 bored systqmp 17726 498652 0 0 3 0x14200 bored systq 3375 62876 0 0 3 0x40014200 bored softclock 24520 444913 0 0 3 0x40014200 idle0 1 67104 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 22667 (syz-executor1) thread 0xffff800020b92720 (442055) exclusive rrwlock inode r = 0 (0xfffffd80653602c8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 Process 34674 (syslogd) thread 0xffff800020be5780 (342009) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff822d9088) locked @ /syzkaller/managers/multicore/kernel/sys/sys/syscall_mi.h:90 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9510 6353K 6361K 78643K 11146 0 0 pcb 23 9K 11K 78643K 1580 0 0 rtable 100 3K 4K 78643K 418 0 0 ifaddr 49 12K 13K 78643K 198 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 22 0 0 iov 0 0K 16K 78643K 265 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1198 75K 76K 78643K 2920 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 63 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 338 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 6 17K 25K 78643K 3011 0 0 sigio 0 0K 0K 78643K 19 0 0 proc 42 38K 70K 78643K 808 0 0 subproc 64 65538K 67586K 78643K 78 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 438 0 0 in_multi 33 2K 2K 78643K 185 0 0 ether_multi 1 0K 0K 78643K 29 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 114 503K 503K 78643K 114 0 0 exec 0 0K 1K 78643K 381 0 0 pfkey data 0 0K 4K 78643K 4 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 95 21K 30K 78643K 10079 0 0 UVM aobj 130 4K 4K 78643K 149 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 1K 78643K 50 0 0 NDP 9 0K 0K 78643K 53 0 0 temp 149 2362K 2430K 78643K 10636 0 0 kqueue 0 0K 0K 78643K 50 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 4 0 0 1 0 1 1 0 8 0 inpcbpl 280 1356 0 1349 1 0 1 1 0 8 0 plimitpl 152 43 0 36 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 41 0 1 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 499 0 495 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 29 0 29 13 13 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 186 0 0 12 0 12 12 0 8 0 art_table 32 187 0 0 2 0 2 2 0 8 0 art_node 16 40 0 6 1 0 1 1 0 8 0 sysvmsgpl 40 23 0 15 1 0 1 1 0 8 0 semapl 112 336 0 326 1 0 1 1 0 8 0 shmpl 112 147 0 19 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 7158 0 5697 49 1 48 48 0 8 0 ffsino 272 7158 0 5697 99 1 98 98 0 8 0 nchpl 144 11661 0 10085 60 0 60 60 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 200 5926 0 0 312 0 312 312 0 8 0 namei 1024 35040 0 35040 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 9 0 9 5 5 0 1 0 8 0 scxspl 192 32528 0 32527 18 17 1 7 0 8 0 sigapl 432 3181 0 3167 2 0 2 2 0 8 0 futexpl 56 43308 0 43307 1 0 1 1 0 8 0 knotepl 112 939 0 912 9 8 1 2 0 8 0 kqueuepl 104 1151 0 1149 1 0 1 1 0 8 0 pipepl 112 2018 0 1999 9 8 1 2 0 8 0 fdescpl 488 3182 0 3167 3 1 2 3 0 8 0 filepl 152 19157 0 19056 21 16 5 7 0 8 1 lockfpl 96 732 0 732 13 12 1 1 0 8 1 lockfspl 24 1427 0 1427 12 11 1 1 0 8 1 sessionpl 112 20 0 10 1 0 1 1 0 8 0 pgrppl 48 59 0 49 1 0 1 1 0 8 0 ucredpl 96 5691 0 5684 1 0 1 1 0 8 0 zombiepl 144 3167 0 3167 1 0 1 1 0 8 1 processpl 840 3197 0 3167 4 0 4 4 0 8 0 procpl 600 9373 0 9331 4 0 4 4 0 8 0 sosppl 128 60 0 60 13 13 0 1 0 8 0 sockpl 384 2857 0 2840 14 11 3 4 0 8 1 mcl64k 65536 628 0 0 72 29 43 66 0 8 0 mcl16k 16384 4 0 0 1 0 1 1 0 8 0 mcl12k 12288 26 0 0 2 0 2 2 0 8 0 mcl9k 9216 16 0 0 2 0 2 2 0 8 0 mcl8k 8192 10 0 0 2 0 2 2 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 7 0 0 1 0 1 1 0 8 0 mcl2k 2048 123 0 0 14 2 12 14 0 8 0 mtagpl 80 4 0 0 1 0 1 1 0 8 0 mbufpl 256 732 0 0 37 0 37 37 0 8 0 bufpl 256 10296 0 3327 436 0 436 436 0 8 0 anonpl 16 334937 0 327458 179 132 47 47 0 125 15 amapchunkpl 152 17899 0 17809 31 26 5 9 0 158 0 amappl16 192 18242 0 17853 195 163 32 32 0 8 12 amappl15 184 3 0 2 2 1 1 1 0 8 0 amappl14 176 1484 0 1481 2 1 1 1 0 8 0 amappl13 168 21 0 18 1 0 1 1 0 8 0 amappl12 160 1528 0 1526 1 0 1 1 0 8 0 amappl11 152 193 0 182 1 0 1 1 0 8 0 amappl10 144 67 0 64 1 0 1 1 0 8 0 amappl9 136 344 0 343 1 0 1 1 0 8 0 amappl8 128 1683 0 1654 1 0 1 1 0 8 0 amappl7 120 33 0 28 1 0 1 1 0 8 0 amappl6 112 1529 0 1521 1 0 1 1 0 8 0 amappl5 104 140 0 128 1 0 1 1 0 8 0 amappl4 96 303 0 285 2 1 1 2 0 8 0 amappl3 88 445 0 439 1 0 1 1 0 8 0 amappl2 80 29251 0 29198 2 0 2 2 0 8 0 amappl1 72 78602 0 78180 24 14 10 19 0 8 0 amappl 72 9622 0 9586 1 0 1 1 0 75 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 dma64 64 259 0 259 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 17 0 17 1 1 0 1 0 8 0 aobjpl 64 148 0 19 3 0 3 3 0 8 0 uaddrrnd 24 3182 0 3167 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3182 0 3167 1 0 1 1 0 8 0 vmmpekpl 168 28008 0 27986 2 0 2 2 0 8 0 vmmpepl 168 340517 0 339132 199 126 73 74 0 357 10 vmsppl 360 3181 0 3167 2 0 2 2 0 8 0 pdppl 4096 6371 0 6334 6 1 5 6 0 8 0 pvpl 32 865705 0 855180 344 221 123 128 0 265 34 pmappl 224 3181 0 3167 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 690 0 35 20 0 20 20 0 8 0