panic: witness_warn Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *249509 27506 32767 0x10 0x4000000 1 syz-executor0 312178 14731 73 0x100010 0 0 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(423f68c2d5d69fed,0,ffff800020b924c8) at witness_warn+0x6e0 witness_debugger sys/kern/subr_witness.c:2546 [inline] witness_warn(423f68c2d5d69fed,0,ffff800020b924c8) at witness_warn+0x6e0 sys/kern/subr_witness.c:1462 userret(bbbedb6aa984be39) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(77d8c9f2dd0f7dab) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(77d8c9f2dd0f7dab) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,5,c,0,3,11953c3f1a0) at Xsyscall+0x128 end of kernel end trace frame: 0x11b6cc00be0, 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{1}> ddb{1}> set $lines = 0 ddb{1}> show panic witness_warn ddb{1}> 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(423f68c2d5d69fed,0,ffff800020b924c8) at witness_warn+0x6e0 witness_debugger sys/kern/subr_witness.c:2546 [inline] witness_warn(423f68c2d5d69fed,0,ffff800020b924c8) at witness_warn+0x6e0 sys/kern/subr_witness.c:1462 userret(bbbedb6aa984be39) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(77d8c9f2dd0f7dab) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(77d8c9f2dd0f7dab) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,5,c,0,3,11953c3f1a0) at Xsyscall+0x128 end of kernel end trace frame: 0x11b6cc00be0, count: -6 ddb{1}> show registers rdi 0xffffffff817251a7 db_enter+0x17 rsi 0x5362 __ALIGN_SIZE+0x4362 rbp 0xffff800020caeea0 rbx 0xffff800020caef40 rdx 0x5363 __ALIGN_SIZE+0x4363 rcx 0xffff80000494d000 rax 0xffff80000494d000 r8 0xffffffff813ff014 kprintf+0x174 r9 0x1 r10 0xe779bc5740c3a27d r11 0x2f16556b57896107 r12 0x3000000008 r13 0xffff800020caeeb0 r14 0x100 r15 0x1 rip 0xffffffff817251a8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020caee90 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor0) pid=249509 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=80, nice=20 forw=0xffffffffffffffff, list=0xffff800020b92018,0xffff800020b92730 process=0xffff800020b949e8 user=0xffff800020caa000, vmspace=0xfffffd806e91c9e0 estcpu=30, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 27506 496999 86790 32767 2 0x10 syz-executor0 27506 173178 86790 32767 3 0x4000090 ttyin syz-executor0 27506 396000 86790 32767 2 0x4000010 syz-executor0 *27506 249509 86790 32767 7 0x4000010 syz-executor0 27506 231215 86790 32767 3 0x4000090 fsleep syz-executor0 27506 161651 86790 32767 2 0x4000010 syz-executor0 86790 6260 95332 32767 2 0x490 syz-executor0 95332 478042 91987 0 3 0x82 wait syz-executor0 621 398920 94089 32767 3 0x90 piperd syz-executor1 94089 62754 91987 0 3 0x82 wait syz-executor1 49938 433587 0 0 3 0x14200 bored sosplice 91987 163959 4068 0 3 0x82 thrsleep syz-fuzzer 91987 335010 4068 0 3 0x4000082 thrsleep syz-fuzzer 91987 362698 4068 0 3 0x4000082 thrsleep syz-fuzzer 91987 390473 4068 0 3 0x4000082 thrsleep syz-fuzzer 91987 500210 4068 0 3 0x4000082 thrsleep syz-fuzzer 91987 285590 4068 0 3 0x4000082 thrsleep syz-fuzzer 91987 443629 4068 0 3 0x4000082 kqread syz-fuzzer 91987 432349 4068 0 3 0x4000082 thrsleep syz-fuzzer 91987 357067 4068 0 3 0x4000082 thrsleep syz-fuzzer 91987 214350 4068 0 3 0x4000082 thrsleep syz-fuzzer 4068 431105 51007 0 3 0x10008a pause ksh 51007 2901 95949 0 3 0x92 select sshd 9695 482043 1 0 3 0x100083 ttyin getty 95949 23875 1 0 3 0x80 select sshd 14731 312178 48830 73 7 0x100010 syslogd 48830 415329 1 0 3 0x100082 netio syslogd 32117 230170 1 77 3 0x100090 poll dhclient 26539 70089 1 0 3 0x80 poll dhclient 37865 296574 0 0 3 0x14200 pgzero zerothread 88338 352042 0 0 3 0x14200 aiodoned aiodoned 20081 149537 0 0 3 0x14200 syncer update 72080 201288 0 0 3 0x14200 cleaner cleaner 75727 94727 0 0 3 0x14200 reaper reaper 60440 425920 0 0 3 0x14200 pgdaemon pagedaemon 19807 296280 0 0 3 0x14200 bored crynlk 66770 88649 0 0 3 0x14200 bored crypto 66854 33432 0 0 3 0x40014200 acpi0 acpi0 78762 137724 0 0 3 0x40014200 idle1 40470 136490 0 0 3 0x14200 bored softnet 82444 486761 0 0 3 0x14200 bored systqmp 66375 32358 0 0 3 0x14200 bored systq 28479 187410 0 0 3 0x40014200 bored softclock 1976 222751 0 0 3 0x40014200 idle0 1 39129 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 27506 (syz-executor0) thread 0xffff800020b924c8 (249509) exclusive rrwlock inode r = 0 (0xfffffd8064e72700) locked @ /syzkaller/managers/setuid/kernel/sys/ufs/ufs/ufs_vnops.c:1547 Process 14731 (syslogd) thread 0xffff800020be59d8 (312178) exclusive rrwlock inode r = 0 (0xfffffd806eb9e098) locked @ /syzkaller/managers/setuid/kernel/sys/ufs/ufs/ufs_vnops.c:1547 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9461 6321K 6321K 78643K 11428 0 0 pcb 23 9K 11K 78643K 3977 0 0 rtable 97 3K 3K 78643K 5799 0 0 ifaddr 35 13K 15K 78643K 1100 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 191 0 0 iov 0 0K 28K 78643K 496 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1201 75K 75K 78643K 6581 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 5K 78643K 102 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 1697 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 7 21K 33K 78643K 7968 0 0 sigio 0 0K 0K 78643K 101 0 0 proc 41 38K 70K 78643K 4812 0 0 subproc 68 69634K 69634K 78643K 6052 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 1012 0 0 in_multi 33 2K 2K 78643K 2251 0 0 ether_multi 1 0K 0K 78643K 66 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 66 291K 291K 78643K 66 0 0 exec 0 0K 1K 78643K 1504 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 98 21K 41K 78643K 24825 0 0 UVM aobj 130 4K 4K 78643K 165 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 0K 78643K 159 0 0 NDP 7 0K 0K 78643K 537 0 0 temp 120 2358K 2438K 78643K 31476 0 0 kqueue 0 0K 0K 78643K 83 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 180 0 176 1 0 1 1 0 8 0 inpcbpl 280 3138 0 3131 1 0 1 1 0 8 0 plimitpl 152 914 0 905 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 1625 0 1585 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 1201 0 1197 1 0 1 1 0 8 0 nd6 48 356 0 352 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 7510 0 7321 17 5 12 13 0 8 0 art_table 32 7511 0 7321 2 0 2 2 0 8 0 art_node 16 1624 0 1590 1 0 1 1 0 8 0 sysvmsgpl 40 12 0 8 1 0 1 1 0 8 0 semapl 112 1695 0 1685 1 0 1 1 0 8 0 shmpl 112 163 0 35 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 12186 0 10653 51 1 50 50 0 8 0 ffsino 272 12186 0 10653 104 1 103 103 0 8 0 nchpl 144 23413 0 21842 60 1 59 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 83077 0 83077 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 56780 0 56780 29 28 1 6 0 8 1 sigapl 432 7607 0 7592 3 1 2 3 0 8 0 futexpl 56 82096 0 82095 1 0 1 1 0 8 0 knotepl 112 4817 0 4790 9 8 1 2 0 8 0 kqueuepl 104 2067 0 2065 1 0 1 1 0 8 0 pipepl 112 9598 0 9579 18 17 1 2 0 8 0 fdescpl 488 7608 0 7592 3 0 3 3 0 8 0 filepl 152 51154 0 51047 25 20 5 7 0 8 0 lockfpl 96 1509 0 1509 14 13 1 1 0 8 1 lockfspl 24 3720 0 3720 13 12 1 1 0 8 1 sessionpl 112 193 0 183 1 0 1 1 0 8 0 pgrppl 48 269 0 259 1 0 1 1 0 8 0 ucredpl 96 18298 0 18289 1 0 1 1 0 8 0 zombiepl 144 7592 0 7592 2 1 1 1 0 8 1 processpl 840 7623 0 7592 4 0 4 4 0 8 0 procpl 600 20949 0 20904 6 2 4 5 0 8 0 srpgc 64 1048 0 1048 24 23 1 1 0 8 1 sosppl 128 141 0 141 38 37 1 1 0 8 1 sockpl 384 7332 0 7315 12 9 3 4 0 8 1 mcl64k 65536 8 0 0 1 0 1 1 0 8 0 mcl16k 16384 11 0 0 2 0 2 2 0 8 0 mcl12k 12288 29 0 0 2 0 2 2 0 8 0 mcl9k 9216 47 0 0 4 2 2 2 0 8 0 mcl8k 8192 17 0 0 3 1 2 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 13 0 0 1 0 1 1 0 8 0 mcl2k 2048 141 0 0 13 2 11 13 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 438 0 0 10 0 10 10 0 8 0 bufpl 256 14806 0 7837 436 0 436 436 0 8 0 anonpl 16 789837 0 785011 238 207 31 41 0 125 0 amapchunkpl 152 53544 0 53453 180 175 5 96 0 158 1 amappl16 192 39131 0 38857 231 214 17 27 0 8 0 amappl15 184 1392 0 1388 1 0 1 1 0 8 0 amappl14 176 734 0 731 2 1 1 1 0 8 0 amappl13 168 932 0 929 1 0 1 1 0 8 0 amappl12 160 975 0 970 1 0 1 1 0 8 0 amappl11 152 2296 0 2287 1 0 1 1 0 8 0 amappl10 144 784 0 781 2 1 1 1 0 8 0 amappl9 136 1746 0 1745 1 0 1 1 0 8 0 amappl8 128 2369 0 2321 2 0 2 2 0 8 0 amappl7 120 959 0 949 1 0 1 1 0 8 0 amappl6 112 1009 0 989 1 0 1 1 0 8 0 amappl5 104 1412 0 1401 1 0 1 1 0 8 0 amappl4 96 1762 0 1736 2 1 1 2 0 8 0 amappl3 88 695 0 690 1 0 1 1 0 8 0 amappl2 80 65745 0 65687 2 0 2 2 0 8 0 amappl1 72 197669 0 197211 45 36 9 19 0 8 0 amappl 72 22534 0 22496 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 64 164 0 35 3 0 3 3 0 8 0 uaddrrnd 24 7608 0 7592 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 7608 0 7592 1 0 1 1 0 8 0 vmmpekpl 168 71200 0 71177 2 0 2 2 0 8 0 vmmpepl 168 865838 0 864461 230 163 67 82 0 357 1 vmsppl 360 7607 0 7592 2 0 2 2 0 8 0 pdppl 4096 15223 0 15184 6 0 6 6 0 8 0 pvpl 32 2176960 0 2168938 434 350 84 113 0 265 0 pmappl 224 7607 0 7592 32 31 1 2 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 604 0 12 18 0 18 18 0 8 0