panic: witness_warn Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 341129 63955 32767 0x10 0 0 syz-executor1 *299503 63955 32767 0x10 0x4000000 1 syz-executor1 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(4c616485bf130fb3,0,ffff800020b924c8) at witness_warn+0x700 witness_debugger sys/kern/subr_witness.c:2549 [inline] witness_warn(4c616485bf130fb3,0,ffff800020b924c8) at witness_warn+0x700 sys/kern/subr_witness.c:1465 userret(b0257453c71ee1bb) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(10cfc7833f87a1b2) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(10cfc7833f87a1b2) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,5,c,0,3,1f4904de0d8) at Xsyscall+0x128 end of kernel end trace frame: 0x1f6f9061780, 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(4c616485bf130fb3,0,ffff800020b924c8) at witness_warn+0x700 witness_debugger sys/kern/subr_witness.c:2549 [inline] witness_warn(4c616485bf130fb3,0,ffff800020b924c8) at witness_warn+0x700 sys/kern/subr_witness.c:1465 userret(b0257453c71ee1bb) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(10cfc7833f87a1b2) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(10cfc7833f87a1b2) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,5,c,0,3,1f4904de0d8) at Xsyscall+0x128 end of kernel end trace frame: 0x1f6f9061780, count: -6 ddb{1}> show registers rdi 0xffffffff819d4fa7 db_enter+0x17 rsi 0x5829 __ALIGN_SIZE+0x4829 rbp 0xffff800020cc99b0 rbx 0xffff800020cc9a50 rdx 0x582a __ALIGN_SIZE+0x482a rcx 0xffff800002747000 rax 0xffff800002747000 r8 0xffffffff81aa9b64 kprintf+0x174 r9 0x1 r10 0xd6061b997fd7d0ba r11 0xb39e9b7a3e7bc332 r12 0x3000000008 r13 0xffff800020cc99c0 r14 0x100 r15 0x1 rip 0xffffffff819d4fa8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020cc99a0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor1) pid=299503 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffff800020b92e28,0xffff800020b93090 process=0xffff800020b953c0 user=0xffff800020cc4000, vmspace=0xfffffd807f00db40 estcpu=31, cpticks=2, pctcpu=0.1 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 63955 341129 17991 32767 7 0x10 syz-executor1 63955 398359 17991 32767 3 0x4000090 fsleep syz-executor1 *63955 299503 17991 32767 7 0x4000010 syz-executor1 63955 441836 17991 32767 3 0x4000090 fsleep syz-executor1 63955 250684 17991 32767 2 0x4000090 syz-executor1 17991 260758 81868 32767 3 0x90 nanosleep syz-executor1 81868 420615 67722 0 3 0x82 wait syz-executor1 98539 186121 64618 32767 3 0x90 piperd syz-executor0 64618 453748 67722 0 3 0x82 wait syz-executor0 55861 169822 0 0 3 0x14200 bored sosplice 67722 334746 69980 0 3 0x82 thrsleep syz-fuzzer 67722 244792 69980 0 3 0x4000082 thrsleep syz-fuzzer 67722 36182 69980 0 3 0x4000082 thrsleep syz-fuzzer 67722 135895 69980 0 3 0x4000082 thrsleep syz-fuzzer 67722 190419 69980 0 3 0x4000082 thrsleep syz-fuzzer 67722 212830 69980 0 3 0x4000082 kqread syz-fuzzer 67722 276322 69980 0 3 0x4000082 thrsleep syz-fuzzer 67722 277741 69980 0 3 0x4000082 thrsleep syz-fuzzer 67722 89419 69980 0 3 0x4000082 thrsleep syz-fuzzer 67722 461165 69980 0 3 0x4000082 thrsleep syz-fuzzer 67722 90798 69980 0 3 0x4000082 thrsleep syz-fuzzer 69980 381453 29079 0 3 0x10008a pause ksh 29079 459811 58727 0 3 0x92 select sshd 17141 236360 1 0 3 0x100083 ttyin getty 58727 80732 1 0 3 0x80 select sshd 41950 131753 16500 73 2 0x100090 syslogd 16500 275332 1 0 3 0x100082 netio syslogd 64811 475268 1 77 3 0x100090 poll dhclient 96338 163107 1 0 3 0x80 poll dhclient 25514 171652 0 0 3 0x14200 pgzero zerothread 18123 257845 0 0 3 0x14200 aiodoned aiodoned 55946 445032 0 0 3 0x14200 syncer update 17696 329957 0 0 3 0x14200 cleaner cleaner 98992 389824 0 0 3 0x14200 reaper reaper 64440 343981 0 0 3 0x14200 pgdaemon pagedaemon 48657 79382 0 0 3 0x14200 bored crynlk 11166 56755 0 0 3 0x14200 bored crypto 83969 8646 0 0 3 0x40014200 acpi0 acpi0 68313 471244 0 0 3 0x40014200 idle1 41907 494641 0 0 3 0x14200 bored softnet 81733 291371 0 0 3 0x14200 bored systqmp 51945 494984 0 0 3 0x14200 bored systq 91362 335822 0 0 3 0x40014200 bored softclock 21918 272821 0 0 3 0x40014200 idle0 1 292922 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 63955 (syz-executor1) thread 0xffff800020b924c8 (299503) exclusive rrwlock inode r = 0 (0xfffffd8074311d58) 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 9462 6321K 6321K 78643K 11224 0 0 pcb 23 9K 11K 78643K 3341 0 0 rtable 97 3K 3K 78643K 4487 0 0 ifaddr 37 14K 15K 78643K 861 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 175 0 0 iov 0 0K 24K 78643K 490 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1202 75K 75K 78643K 5546 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 81 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 574 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 7 21K 33K 78643K 6330 0 0 sigio 0 0K 0K 78643K 111 0 0 proc 41 38K 70K 78643K 3919 0 0 subproc 68 69634K 71682K 78643K 4658 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 903 0 0 in_multi 33 2K 2K 78643K 1699 0 0 ether_multi 1 0K 0K 78643K 49 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 72 318K 318K 78643K 72 0 0 exec 0 0K 1K 78643K 1189 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 100 21K 31K 78643K 20370 0 0 UVM aobj 129 4K 4K 78643K 157 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 170 0 0 NDP 5 0K 0K 78643K 414 0 0 temp 121 2362K 2434K 78643K 25345 0 0 kqueue 0 0K 0K 78643K 100 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 64 139 0 135 1 0 1 1 0 8 0 inpcbpl 280 2763 0 2756 1 0 1 1 0 8 0 plimitpl 152 331 0 322 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 1256 0 1216 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 1159 0 1155 1 0 1 1 0 8 0 nd6 48 274 0 270 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 5873 0 5685 12 0 12 12 0 8 0 art_table 32 5874 0 5685 2 0 2 2 0 8 0 art_node 16 1255 0 1221 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 3 1 0 1 1 0 8 0 semapl 112 570 0 560 1 0 1 1 0 8 0 shmpl 112 155 0 28 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 9863 0 8347 50 0 50 50 0 8 0 ffsino 272 9863 0 8347 103 1 102 102 0 8 0 nchpl 144 18493 0 16921 59 0 59 59 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 67571 0 67571 4 3 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 48799 0 48799 39 38 1 6 0 8 1 sigapl 432 6092 0 6077 3 1 2 3 0 8 0 futexpl 56 62717 0 62715 3 2 1 1 0 8 0 knotepl 112 3770 0 3743 6 5 1 2 0 8 0 kqueuepl 104 1684 0 1682 1 0 1 1 0 8 0 pipepl 112 5444 0 5425 17 16 1 2 0 8 0 fdescpl 488 6093 0 6077 3 0 3 3 0 8 0 filepl 152 42152 0 42049 24 19 5 7 0 8 0 lockfpl 96 1576 0 1576 9 8 1 1 0 8 1 lockfspl 24 3589 0 3589 8 7 1 1 0 8 1 sessionpl 112 152 0 142 1 0 1 1 0 8 0 pgrppl 48 230 0 220 1 0 1 1 0 8 0 ucredpl 96 15784 0 15775 1 0 1 1 0 8 0 zombiepl 144 6077 0 6077 2 1 1 1 0 8 1 processpl 840 6108 0 6077 4 0 4 4 0 8 0 procpl 600 17195 0 17150 4 0 4 4 0 8 0 srpgc 64 792 0 792 20 19 1 1 0 8 1 sosppl 128 122 0 122 21 21 0 1 0 8 0 sockpl 384 6253 0 6236 14 11 3 4 0 8 1 mcl64k 65536 14 0 0 2 0 2 2 0 8 0 mcl16k 16384 6 0 0 1 0 1 1 0 8 0 mcl12k 12288 23 0 0 2 0 2 2 0 8 0 mcl9k 9216 26 0 0 2 1 1 2 0 8 0 mcl8k 8192 17 0 0 3 0 3 3 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 126 0 0 14 2 12 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 415 0 0 11 0 11 11 0 8 0 bufpl 256 14646 0 7677 436 0 436 436 0 8 0 anonpl 16 694414 0 688738 176 140 36 41 0 125 0 amapchunkpl 152 42018 0 41926 82 73 9 12 0 158 4 amappl16 192 33869 0 33588 235 219 16 28 0 8 0 amappl15 184 1065 0 1061 1 0 1 1 0 8 0 amappl14 176 845 0 841 2 1 1 1 0 8 0 amappl13 168 1072 0 1068 1 0 1 1 0 8 0 amappl12 160 1195 0 1192 1 0 1 1 0 8 0 amappl11 152 1344 0 1335 1 0 1 1 0 8 0 amappl10 144 412 0 406 2 1 1 1 0 8 0 amappl9 136 966 0 965 1 0 1 1 0 8 0 amappl8 128 2292 0 2240 2 0 2 2 0 8 0 amappl7 120 1070 0 1058 1 0 1 1 0 8 0 amappl6 112 659 0 652 1 0 1 1 0 8 0 amappl5 104 1097 0 1083 1 0 1 1 0 8 0 amappl4 96 1207 0 1180 2 1 1 2 0 8 0 amappl3 88 632 0 626 1 0 1 1 0 8 0 amappl2 80 53135 0 53075 2 0 2 2 0 8 0 amappl1 72 160497 0 160035 24 14 10 19 0 8 0 amappl 72 18463 0 18425 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 64 156 0 28 3 0 3 3 0 8 0 uaddrrnd 24 6093 0 6077 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 6093 0 6077 1 0 1 1 0 8 0 vmmpekpl 168 55117 0 55094 2 0 2 2 0 8 0 vmmpepl 168 699454 0 698061 216 143 73 83 0 357 5 vmsppl 360 6092 0 6077 2 0 2 2 0 8 0 pdppl 4096 12193 0 12154 8 2 6 6 0 8 0 pvpl 32 1831075 0 1822030 389 285 104 116 0 265 18 pmappl 224 6092 0 6077 29 27 2 2 0 8 1 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 604 0 10 17 0 17 17 0 8 0