panic: witness_warn Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 177340 47515 0 0 0 1 syz-executor0 *436150 47515 0 0 0x4000000 0 syz-executor0 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(2591ade014702971,0,ffff800020b939e0) at witness_warn+0x6e0 witness_debugger sys/kern/subr_witness.c:2546 [inline] witness_warn(2591ade014702971,0,ffff800020b939e0) at witness_warn+0x6e0 sys/kern/subr_witness.c:1462 userret(306524687df4d107) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(fa17f1d97e55dff7) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(fa17f1d97e55dff7) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,0,ffffffffffffffb9,0,3,7601cc063f8) at Xsyscall+0x128 end of kernel end trace frame: 0x7622f5f4b10, 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(2591ade014702971,0,ffff800020b939e0) at witness_warn+0x6e0 witness_debugger sys/kern/subr_witness.c:2546 [inline] witness_warn(2591ade014702971,0,ffff800020b939e0) at witness_warn+0x6e0 sys/kern/subr_witness.c:1462 userret(306524687df4d107) at userret+0x361 sys/kern/kern_sig.c:1899 syscall(fa17f1d97e55dff7) at syscall+0x680 mi_syscall_return sys/sys/syscall_mi.h:122 [inline] syscall(fa17f1d97e55dff7) at syscall+0x680 sys/arch/amd64/amd64/trap.c:605 Xsyscall(6,0,ffffffffffffffb9,0,3,7601cc063f8) at Xsyscall+0x128 end of kernel end trace frame: 0x7622f5f4b10, count: -6 ddb{0}> show registers rdi 0xffffffff813eeb67 db_enter+0x17 rsi 0x40d8 __ALIGN_SIZE+0x30d8 rbp 0xffff800020cc7410 rbx 0xffff800020cc74b0 rdx 0x40d9 __ALIGN_SIZE+0x30d9 rcx 0xffff800001346000 rax 0xffff800001346000 r8 0xffffffff810055d4 kprintf+0x174 r9 0x1 r10 0x50b9d62fc165b94e r11 0xab70714fe0b3bb2e r12 0x3000000008 r13 0xffff800020cc7420 r14 0x100 r15 0x1 rip 0xffffffff813eeb68 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020cc7400 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor0) pid=436150 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=80, nice=20 forw=0xffffffffffffffff, list=0xffff800020b93530,0xffffffff82324448 process=0xffff800020b94010 user=0xffff800020cc2000, vmspace=0xfffffd807f00cb40 estcpu=30, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 47515 177340 52703 0 7 0 syz-executor0 47515 256288 52703 0 3 0x4000080 poll syz-executor0 47515 303829 52703 0 3 0x4000080 poll syz-executor0 47515 227302 52703 0 3 0x4000080 fsleep syz-executor0 47515 446256 52703 0 2 0x4000000 syz-executor0 47515 480588 52703 0 3 0x4000080 fsleep syz-executor0 *47515 436150 52703 0 7 0x4000000 syz-executor0 3313 351077 1 0 3 0x100083 ttyin getty 27384 276285 0 0 3 0x14200 bored sosplice 35152 246536 31950 0 3 0x82 piperd syz-executor1 52703 103702 31950 0 3 0x82 nanosleep syz-executor0 31950 138428 89844 0 3 0x82 thrsleep syz-fuzzer 31950 174310 89844 0 3 0x4000082 thrsleep syz-fuzzer 31950 30356 89844 0 3 0x4000082 thrsleep syz-fuzzer 31950 364129 89844 0 3 0x4000082 thrsleep syz-fuzzer 31950 395829 89844 0 3 0x4000082 kqread syz-fuzzer 31950 441567 89844 0 3 0x4000082 thrsleep syz-fuzzer 31950 101124 89844 0 3 0x4000082 thrsleep syz-fuzzer 31950 27752 89844 0 3 0x4000082 thrsleep syz-fuzzer 31950 101184 89844 0 3 0x4000082 thrsleep syz-fuzzer 31950 342556 89844 0 3 0x4000082 thrsleep syz-fuzzer 31950 92934 89844 0 3 0x4000082 thrsleep syz-fuzzer 89844 296549 64703 0 3 0x10008a pause ksh 64703 155109 40272 0 3 0x92 select sshd 40272 468414 1 0 3 0x80 select sshd 70576 369417 62142 73 3 0x100010 biowait syslogd 62142 42153 1 0 3 0x100082 netio syslogd 21464 416884 1 77 3 0x100090 poll dhclient 47465 54967 1 0 3 0x80 poll dhclient 21105 420796 0 0 3 0x14200 pgzero zerothread 29756 521095 0 0 3 0x14200 aiodoned aiodoned 93516 371341 0 0 3 0x14200 syncer update 85905 96970 0 0 3 0x14200 cleaner cleaner 88700 42760 0 0 3 0x14200 reaper reaper 85336 116910 0 0 3 0x14200 pgdaemon pagedaemon 28115 453285 0 0 3 0x14200 bored crynlk 93130 25004 0 0 3 0x14200 bored crypto 32650 412747 0 0 3 0x40014200 acpi0 acpi0 88476 74413 0 0 3 0x40014200 idle1 90490 495846 0 0 3 0x14200 bored softnet 78890 7838 0 0 3 0x14200 bored systqmp 73754 417545 0 0 3 0x14200 bored systq 44855 166821 0 0 3 0x40014200 bored softclock 50257 488922 0 0 3 0x40014200 idle0 1 420872 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 47515 (syz-executor0) thread 0xffff800020b939e0 (436150) exclusive rrwlock inode r = 0 (0xfffffd807cb6c4d8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 Process 70576 (syslogd) thread 0xffff800020be5528 (369417) exclusive rrwlock inode r = 0 (0xfffffd806eba85e8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9540 10453K 10461K 78643K 12917 0 0 pcb 23 9K 11K 78643K 5940 0 0 rtable 100 3K 4K 78643K 1124 0 0 ifaddr 59 16K 18K 78643K 624 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 19 0 0 iov 0 0K 24K 78643K 1010 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1193 75K 76K 78643K 8561 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 188 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 1131 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 5 13K 25K 78643K 11273 0 0 sigio 0 0K 0K 78643K 238 0 0 proc 42 38K 70K 78643K 2024 0 0 subproc 64 65538K 67586K 78643K 153 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 1288 0 0 in_multi 33 2K 2K 78643K 484 0 0 ether_multi 1 0K 0K 78643K 78 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 138 609K 609K 78643K 138 0 0 exec 0 0K 1K 78643K 950 0 0 pfkey data 0 0K 4K 78643K 7 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 142 23K 32K 78643K 37014 0 0 UVM aobj 130 6K 6K 78643K 146 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 284 0 0 NDP 12 0K 0K 78643K 173 0 0 temp 172 2363K 2436K 78643K 31922 0 0 kqueue 0 0K 0K 78643K 106 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 4694 0 4687 2 1 1 2 0 8 0 plimitpl 152 140 0 133 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 1661 0 1657 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 112 0 112 49 49 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 38 0 26 2 1 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 1129 0 1119 1 0 1 1 0 8 0 shmpl 112 144 0 16 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 24047 0 22425 53 0 53 53 0 8 0 ffsino 272 24047 0 22425 109 0 109 109 0 8 0 nchpl 144 40387 0 38809 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 128421 0 128421 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 43 0 43 26 25 1 1 0 8 1 scxspl 192 124417 0 124416 49 48 1 6 0 8 0 sigapl 432 11448 0 11435 2 0 2 2 0 8 0 futexpl 56 140203 0 140201 2 1 1 1 0 8 0 knotepl 112 2835 0 2808 16 15 1 2 0 8 0 kqueuepl 104 3736 0 3734 1 0 1 1 0 8 0 pipepl 112 7412 0 7393 24 23 1 2 0 8 0 fdescpl 488 11449 0 11435 3 1 2 3 0 8 0 filepl 152 72852 0 72753 33 28 5 7 0 8 1 lockfpl 96 2701 0 2701 33 32 1 1 0 8 1 lockfspl 24 5475 0 5475 35 34 1 1 0 8 1 sessionpl 112 25 0 15 1 0 1 1 0 8 0 pgrppl 48 160 0 150 1 0 1 1 0 8 0 ucredpl 96 27073 0 27066 1 0 1 1 0 8 0 zombiepl 144 11435 0 11435 2 1 1 1 0 8 1 processpl 840 11464 0 11435 4 0 4 4 0 8 0 procpl 600 35596 0 35551 4 0 4 4 0 8 0 sosppl 128 197 0 197 53 53 0 1 0 8 0 sockpl 384 10368 0 10351 29 26 3 4 0 8 1 mcl64k 65536 1467 0 0 130 97 33 66 0 8 3 mcl16k 16384 25 0 0 4 1 3 3 0 8 1 mcl12k 12288 57 0 0 3 1 2 2 0 8 0 mcl9k 9216 47 0 0 2 0 2 2 0 8 0 mcl8k 8192 35 0 0 5 3 2 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 8 0 0 1 0 1 1 0 8 0 mcl2k 2048 169 0 0 14 3 11 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 1515 0 0 37 1 36 37 0 8 0 bufpl 256 24145 0 17176 436 0 436 436 0 8 0 anonpl 16 1415063 0 1407764 467 424 43 62 0 125 8 amapchunkpl 152 71163 0 71059 164 159 5 9 0 158 0 amappl16 192 82845 0 82473 612 588 24 43 0 8 5 amappl15 184 1 0 1 1 1 0 1 0 8 0 amappl14 176 1 0 1 1 1 0 1 0 8 0 amappl13 168 25 0 21 1 0 1 1 0 8 0 amappl12 160 29 0 26 1 0 1 1 0 8 0 amappl11 152 192 0 182 1 0 1 1 0 8 0 amappl10 144 11058 0 11055 1 0 1 1 0 8 0 amappl9 136 344 0 343 1 0 1 1 0 8 0 amappl8 128 307 0 247 2 0 2 2 0 8 0 amappl7 120 32 0 27 1 0 1 1 0 8 0 amappl6 112 52 0 44 1 0 1 1 0 8 0 amappl5 104 293 0 279 1 0 1 1 0 8 0 amappl4 96 385 0 363 2 1 1 2 0 8 0 amappl3 88 648 0 643 1 0 1 1 0 8 0 amappl2 80 119626 0 119576 2 0 2 2 0 8 0 amappl1 72 252481 0 252050 24 14 10 19 0 8 0 amappl 72 36041 0 36001 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 64 145 0 16 3 0 3 3 0 8 0 uaddrrnd 24 11449 0 11435 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 11449 0 11435 1 0 1 1 0 8 0 vmmpekpl 168 92941 0 92919 2 0 2 2 0 8 0 vmmpepl 168 1259368 0 1257985 420 353 67 83 0 357 2 vmsppl 360 11448 0 11435 2 0 2 2 0 8 0 pdppl 4096 22905 0 22870 6 1 5 6 0 8 0 pvpl 32 3589389 0 3578968 789 671 118 167 0 265 27 pmappl 224 11448 0 11435 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 765 0 109 20 0 20 20 0 8 0