uvm_fault(0xfffffd806e8be750, 0x9, 0, 1) -> e kernel: page fault trap, code=0 Stopped at witness_checkorder+0x1ec: movl 0x8(%r14),%ebx TID PID UID PRFLAGS PFLAGS CPU COMMAND 169571 69862 0 0x2000002 0x4000000 1 syz-fuzzer witness_checkorder(fffffd806efa1010,9,0) at witness_checkorder+0x1ec sys/kern/subr_witness.c:794 mtx_enter(fffffd806efa1000) at mtx_enter+0x3e sys/kern/kern_lock.c:265 knote_remove(ffff8000211d8ab8,fffffd806efa1000,fffffd806efa1088,4,0) at knote_remove+0x20d sys/kern/kern_event.c:1881 knote_fdclose(ffff8000211d8ab8,4) at knote_fdclose+0xae sys/kern/kern_event.c:1934 fdfree(ffff8000211d8ab8) at fdfree+0xdf sys/kern/kern_descrip.c:1196 exit1(ffff8000211d8ab8,0,0,1) at exit1+0x3e4 sys/kern/kern_exit.c:206 sys_exit(ffff8000211d8ab8,ffff800025d3d120,ffff800025d3d170) at sys_exit+0x1a sys/kern/kern_exit.c:89 syscall(ffff800025d3d1f0) at syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline] syscall(ffff800025d3d1f0) at syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x743d86004fb0, count: 6 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}> set $maxwidth = 0 ddb{0}> show panic *cpu0: uvm_fault(0xfffffd806e8be750, 0x9, 0, 1) -> e ddb{0}> trace witness_checkorder(fffffd806efa1010,9,0) at witness_checkorder+0x1ec sys/kern/subr_witness.c:794 mtx_enter(fffffd806efa1000) at mtx_enter+0x3e sys/kern/kern_lock.c:265 knote_remove(ffff8000211d8ab8,fffffd806efa1000,fffffd806efa1088,4,0) at knote_remove+0x20d sys/kern/kern_event.c:1881 knote_fdclose(ffff8000211d8ab8,4) at knote_fdclose+0xae sys/kern/kern_event.c:1934 fdfree(ffff8000211d8ab8) at fdfree+0xdf sys/kern/kern_descrip.c:1196 exit1(ffff8000211d8ab8,0,0,1) at exit1+0x3e4 sys/kern/kern_exit.c:206 sys_exit(ffff8000211d8ab8,ffff800025d3d120,ffff800025d3d170) at sys_exit+0x1a sys/kern/kern_exit.c:89 syscall(ffff800025d3d1f0) at syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline] syscall(ffff800025d3d1f0) at syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x743d86004fb0, count: -9 ddb{0}> show registers rdi 0 rsi 0x20000 acpi_pdirpa+0xbe63 rbp 0xffff800025d3cec0 rbx 0xe rdx 0 rcx 0xffff8000211d8ab8 rax 0xffffffff82c40ff0 cpu_info_full_primary+0x1ff0 r8 0x1 r9 0 r10 0x5383ba633c26f85 r11 0xac22cfe2826e25eb r12 0 r13 0xfffffd806efa1010 r14 0x1 r15 0xffff8000211d8ab8 rip 0xffffffff8252c28c witness_checkorder+0x1ec cs 0x8 rflags 0x10246 __ALIGN_SIZE+0xf246 rsp 0xffff800025d3ce10 ss 0x10 witness_checkorder+0x1ec: movl 0x8(%r14),%ebx ddb{0}> show proc PROC (syz-executor.5) pid=240444 stat=onproc flags process=1008 proc=2000 pri=0, usrpri=83, nice=20 forw=0xffffffffffffffff, list=0xffff8000211d82c0,0xffffffff82d034b0 process=0xffff800021299510 user=0xffff800025d38000, vmspace=0xfffffd806e8be750 estcpu=33, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 41811 446281 88574 0 2 0 syz-executor.4 41811 376168 88574 0 3 0x4000080 netio syz-executor.4 41811 410414 88574 0 3 0x4000000 inode syz-executor.4 2698 139774 39464 0 3 0x80 nanoslp syz-executor.0 2698 142776 39464 0 3 0x4000080 nanoslp syz-executor.0 246 20073 69862 0 3 0x82 nanoslp syz-executor.5 36083 293648 1 0 3 0x100083 ttyin getty 54281 69012 69862 0 2 0x2 syz-executor.6 86170 488183 0 0 3 0x14200 acct acct 82138 113788 69862 0 2 0x2 syz-executor.1 83724 286109 69862 0 2 0x2 syz-executor.3 7710 147922 0 0 3 0x14280 nfsidl nfsio 99751 324415 0 0 3 0x14280 nfsidl nfsio 30540 262281 0 0 3 0x14280 nfsidl nfsio 65709 509205 0 0 3 0x14280 nfsidl nfsio 56901 254755 0 0 3 0x14280 nfsidl nfsio 62479 265956 0 0 3 0x14280 nfsidl nfsio 38943 172426 0 0 3 0x14280 nfsidl nfsio 81602 213545 0 0 3 0x14280 nfsidl nfsio 14717 440429 0 0 3 0x14280 nfsidl nfsio 10558 220787 0 0 3 0x14280 nfsidl nfsio 29509 482842 0 0 3 0x14280 nfsidl nfsio 51587 149209 0 0 3 0x14280 nfsidl nfsio 68179 359179 0 0 3 0x14280 nfsidl nfsio 4536 299836 0 0 3 0x14280 nfsidl nfsio 42008 157240 0 0 3 0x14280 nfsidl nfsio 11624 486613 0 0 3 0x14280 nfsidl nfsio 30564 163467 0 0 3 0x14280 nfsidl nfsio 84739 23684 0 0 3 0x14280 nfsidl nfsio 2056 116479 0 0 3 0x14280 nfsidl nfsio 34061 118128 0 0 3 0x14280 nfsidl nfsio 76772 393006 0 0 3 0x14200 bored sosplice 20571 391521 69862 0 2 0x482 syz-executor.7 88574 301243 69862 0 3 0x82 nanoslp syz-executor.4 8500 219736 69862 0 2 0x2 syz-executor.2 39464 88107 69862 0 3 0x82 nanoslp syz-executor.0 69862 320924 23647 0 3 0x2000082 thrsleep syz-fuzzer 69862 316783 23647 0 2 0x6000002 syz-fuzzer 69862 311042 23647 0 3 0x6000082 thrsleep syz-fuzzer 69862 72452 23647 0 3 0x6000082 wait syz-fuzzer 69862 169571 23647 0 7 0x6000002 syz-fuzzer 69862 223408 23647 0 3 0x6000082 thrsleep syz-fuzzer 69862 417585 23647 0 2 0x6000002 syz-fuzzer 69862 219880 23647 0 3 0x6000082 wait syz-fuzzer 69862 20391 23647 0 3 0x6000082 wait syz-fuzzer 69862 236772 23647 0 3 0x6000082 wait syz-fuzzer 69862 353124 23647 0 3 0x6000082 thrsleep syz-fuzzer 69862 473742 23647 0 3 0x6000082 wait syz-fuzzer 69862 134024 23647 0 3 0x6000082 wait syz-fuzzer 69862 26209 23647 0 3 0x6000082 wait syz-fuzzer 69862 48677 23647 0 3 0x6000082 wait syz-fuzzer 69862 236403 23647 0 3 0x6000082 kqread syz-fuzzer 23647 278629 44538 0 3 0x10008a sigsusp ksh 44538 519786 30663 0 3 0x9a kqread sshd 30663 361724 1 0 3 0x88 kqread sshd 16176 61457 32570 74 3 0x1100092 bpf pflogd 32570 299610 1 0 3 0x80 netio pflogd 79671 86690 14132 73 3 0x1100090 kqread syslogd 14132 377140 1 0 3 0x100082 netio syslogd 46064 329636 1 0 3 0x100080 kqread resolvd 87865 325572 40909 77 3 0x100092 kqread dhcpleased 45142 419869 40909 77 3 0x100092 kqread dhcpleased 40909 392193 1 0 3 0x80 kqread dhcpleased 70529 471482 0 0 3 0x14200 bored smr 18446 388486 0 0 2 0x14200 zerothread 7577 360332 0 0 3 0x14200 aiodoned aiodoned 51649 408307 0 0 3 0x14200 syncer update 18598 455834 0 0 3 0x14200 cleaner cleaner 77577 335109 0 0 2 0x14200 reaper 68345 26424 0 0 3 0x14200 pgdaemon pagedaemon 24314 231684 0 0 3 0x14200 bored viomb 74097 286541 0 0 3 0x40014200 acpi0 acpi0 16543 520569 0 0 3 0x40014200 idle1 70222 474474 0 0 3 0x14200 bored softnet3 36080 349019 0 0 3 0x14200 bored softnet2 77580 136027 0 0 3 0x14200 bored softnet1 39089 311494 0 0 2 0x14200 softnet0 63156 182896 0 0 3 0x14200 bored systqmp 23569 282976 0 0 3 0x14200 bored systq 93577 151295 0 0 2 0x40014200 softclock 63858 315013 0 0 3 0x40014200 idle0 1 239968 0 0 3 0x80082 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 41811 (syz-executor.4) thread 0xffff8000211d92b0 (376168) exclusive rrwlock inode r = 0 (0xfffffd806e21bc58) #0 witness_lock+0x447 #1 rw_enter+0x3c8 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x8c sys/kern/kern_rwlock.c:464 #3 VOP_LOCK+0x8b sys/kern/vfs_vops.c:518 #4 ufs_ihashins+0x46 sys/ufs/ufs/ufs_ihash.c:140 #5 ffs_vget+0x141 sys/ufs/ffs/ffs_vfsops.c:1343 #6 ufs_lookup+0x122c sys/ufs/ufs/ufs_lookup.c:582 #7 VOP_LOOKUP+0x5c sys/kern/vfs_vops.c:85 #8 vfs_lookup+0x6e2 sys/kern/vfs_lookup.c:566 #9 namei+0x55a sys/kern/vfs_lookup.c:250 #10 vn_open+0xf8 sys/kern/vfs_vnops.c:140 #11 vndioctl+0xa0b sys/dev/vnd.c:457 #12 VOP_IOCTL+0x97 sys/kern/vfs_vops.c:264 #13 vn_ioctl+0xc0 sys/kern/vfs_vnops.c:525 #14 sys_ioctl+0x4a2 #15 syscall+0x606 mi_syscall sys/sys/syscall_mi.h:110 [inline] #15 syscall+0x606 sys/arch/amd64/amd64/trap.c:623 #16 Xsyscall+0x128 Process 41811 (syz-executor.4) thread 0xffff8000211d82c0 (410414) exclusive rrwlock inode r = 0 (0xfffffd806cf86e78) #0 witness_lock+0x447 #1 rw_enter+0x3c8 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x8c sys/kern/kern_rwlock.c:464 #3 VOP_LOCK+0x8b sys/kern/vfs_vops.c:518 #4 vn_lock+0x84 sys/kern/vfs_vnops.c:564 #5 vfs_lookup+0xd5 sys/kern/vfs_lookup.c:418 #6 namei+0x55a sys/kern/vfs_lookup.c:250 #7 vn_open+0xf8 sys/kern/vfs_vnops.c:140 #8 doopenat+0x26e sys/kern/vfs_syscalls.c:1126 #9 syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline] #9 syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623 #10 Xsyscall+0x128 Process 54281 (syz-executor.6) thread 0xffff8000211d9800 (69012) exclusive rrwlock inode r = 0 (0xfffffd806e2b41b8) #0 witness_lock+0x447 #1 rw_enter+0x3c8 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x8c sys/kern/kern_rwlock.c:464 #3 VOP_LOCK+0x8b sys/kern/vfs_vops.c:518 #4 vn_lock+0x84 sys/kern/vfs_vnops.c:564 #5 vget+0x200 sys/kern/vfs_subr.c:676 #6 ufs_ihashget+0x121 sys/ufs/ufs/ufs_ihash.c:119 #7 ffs_vget+0x7c sys/ufs/ffs/ffs_vfsops.c:1314 #8 ufs_lookup+0x13ba sys/ufs/ufs/ufs_lookup.c:487 #9 VOP_LOOKUP+0x5c sys/kern/vfs_vops.c:85 #10 vfs_lookup+0x6e2 sys/kern/vfs_lookup.c:566 #11 namei+0x55a sys/kern/vfs_lookup.c:250 #12 dounlinkat+0x9d sys/kern/vfs_syscalls.c:1847 #13 syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline] #13 syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd8065f68a28) #0 witness_lock+0x447 #1 rw_enter+0x3c8 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x8c sys/kern/kern_rwlock.c:464 #3 VOP_LOCK+0x8b sys/kern/vfs_vops.c:518 #4 vn_lock+0x84 sys/kern/vfs_vnops.c:564 #5 vfs_lookup+0xd5 sys/kern/vfs_lookup.c:418 #6 namei+0x55a sys/kern/vfs_lookup.c:250 #7 dounlinkat+0x9d sys/kern/vfs_syscalls.c:1847 #8 syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline] #8 syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10231 6484K 6965K 78643K 16473 0 pcb 13 17K 19K 78643K 111 0 rtable 239 7K 7K 78643K 592 0 pf 35 10K 10K 78643K 127 0 ifaddr 46 16K 16K 78643K 106 0 ifgroup 60 2K 2K 78643K 195 0 sysctl 2 0K 0K 78643K 2 0 counters 62 36K 36K 78643K 134 0 ioctlops 0 0K 4K 78643K 1505 0 iov 0 0K 16K 78643K 275 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1379 86K 86K 78643K 3133 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 41 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 152 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 13 45K 85K 78643K 3762 0 sigio 0 0K 0K 78643K 39 0 proc 70 91K 128K 78643K 876 0 subproc 104 6K 6K 78643K 189 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 73 0 in_multi 99 7K 7K 78643K 177 0 ether_multi 1 0K 0K 78643K 4 0 mrt 1 0K 0K 78643K 4 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 271 1208K 1208K 78643K 271 0 exec 0 0K 1K 78643K 873 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 372 91K 106K 78643K 39325 0 UVM aobj 131 4K 4K 78643K 137 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 154 0 NDP 13 0K 2K 78643K 77 0 temp 76 5920K 6000K 78643K 45011 0 kqueue 12 18K 24K 78643K 232 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 22 0 0 1 0 1 1 0 8 0 rtpcb 120 159 0 156 2 1 1 2 0 8 0 rtentry 112 181 0 70 4 0 4 4 0 8 0 unpcb 144 2757 0 2740 40 37 3 10 0 8 2 syncache 304 28 0 28 7 7 0 1 0 8 0 tcpqe 32 241 0 241 6 6 0 1 0 8 0 tcpcb 808 3564 0 3554 83 74 9 24 0 8 7 arp 120 30 0 12 1 0 1 1 0 8 0 inpcb 368 4632 0 4615 76 68 8 20 0 8 6 nd6 136 46 0 21 1 0 1 1 0 8 0 pkpcb 40 4 0 4 1 1 0 1 0 8 0 kcovpl 48 14 0 6 1 0 1 1 0 8 0 ppxss 1256 9 0 9 2 2 0 1 0 8 0 pffrag 232 16 0 15 2 1 1 1 0 482 0 pffrnode 88 16 0 15 2 1 1 1 0 8 0 pffrent 40 38 0 37 2 1 1 1 0 8 0 pfosfp 40 1428 0 1005 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 110 0 85 1 0 1 1 0 8 0 pfstkey 128 110 0 85 1 0 1 1 0 8 0 pfstate 376 110 0 85 7 4 3 3 0 8 0 pfrule 1344 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 749 0 285 31 2 29 30 0 8 0 art_table 32 750 0 285 4 0 4 4 0 8 0 art_node 16 180 0 79 1 0 1 1 0 8 0 sysvmsgpl 40 31 0 17 1 0 1 1 0 8 0 semapl 112 148 0 138 1 0 1 1 0 8 0 shmpl 112 134 0 6 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 6410 0 4935 93 0 93 93 0 8 0 ffsino 272 6410 0 4935 99 0 99 99 0 8 0 nchpl 144 12215 0 10558 63 0 63 63 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 39314 0 39313 6 5 1 2 0 8 0 percpumem 16 80 0 36 1 0 1 1 0 8 0 vmpool 696 4 0 4 1 1 0 1 0 8 0 kstatmem 264 98 0 72 2 0 2 2 0 8 0 scxspl 216 42578 0 42578 16 15 1 8 1 8 1 plimitpl 152 158 0 142 1 0 1 1 0 8 0 sigapl 424 4097 0 4031 9 1 8 8 0 8 0 futexpl 64 28709 0 28709 4 3 1 1 0 8 1 knotepl 120 352 0 0 7 0 7 7 0 8 0 kqueuepl 216 468 0 460 7 6 1 5 0 8 0 pipepl 320 954 0 926 27 24 3 8 0 8 0 fdescpl 496 4058 0 4032 5 0 5 5 0 8 0 filepl 152 26153 0 25908 66 53 13 20 0 8 3 lockfpl 104 1559 0 1557 2 1 1 2 0 8 0 lockfspl 48 546 0 544 1 0 1 1 0 8 0 sessionpl 144 32 0 15 1 0 1 1 0 8 0 pgrppl 48 53 0 36 1 0 1 1 0 8 0 ucredpl 104 3296 0 3283 1 0 1 1 0 8 0 zombiepl 144 4033 0 4031 1 0 1 1 0 8 0 processpl 1072 4097 0 4031 5 0 5 5 0 8 0 procpl 680 10726 0 10641 14 5 9 10 0 8 0 sosppl 168 35 0 34 8 7 1 1 0 8 0 sockpl 488 7591 0 7554 194 181 13 34 0 8 8 mcl64k 65536 17 0 0 3 0 3 3 0 8 0 mcl16k 16384 15 0 0 2 0 2 2 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 14 0 0 1 0 1 1 0 8 0 mcl8k 8192 25 0 0 4 1 3 3 0 8 0 mcl4k 4096 20 0 0 3 0 3 3 0 8 0 mcl2k2 2112 8 0 0 1 0 1 1 0 8 0 mcl2k 2048 285 0 0 34 1 33 34 0 8 1 mtagpl 96 256 0 0 5 0 5 5 0 8 0 mbufpl 256 1271 0 0 66 0 66 66 0 8 0 bufpl 288 11072 0 4743 453 0 453 453 0 8 0 anonpl 24 530543 0 516760 163 59 104 122 0 186 9 amapchunkpl 152 125286 0 124461 66 23 43 46 0 158 2 amappl16 200 11993 0 11562 63 39 24 36 0 8 0 amappl15 192 85 0 85 1 1 0 1 0 8 0 amappl14 184 219 0 201 3 2 1 2 0 8 0 amappl13 176 9 0 9 2 2 0 1 0 8 0 amappl12 168 4827 0 4800 3 1 2 2 0 8 0 amappl11 160 58 0 44 1 0 1 1 0 8 0 amappl10 152 32 0 21 1 0 1 1 0 8 0 amappl9 144 208 0 205 1 0 1 1 0 8 0 amappl8 136 341 0 240 4 0 4 4 0 8 0 amappl7 128 91 0 74 2 0 2 2 0 8 0 amappl6 120 316 0 292 2 1 1 2 0 8 0 amappl5 112 289 0 276 1 0 1 1 0 8 0 amappl4 104 696 0 651 3 1 2 3 0 8 0 amappl3 96 24897 0 24823 5 2 3 4 0 8 0 amappl2 88 4420 0 4354 3 1 2 3 0 8 0 amappl1 80 23276 0 22725 23 10 13 23 0 8 0 amappl 88 38615 0 38394 8 1 7 7 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 72 136 0 6 3 0 3 3 0 8 0 uaddrrnd 24 4062 0 4036 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4062 0 4036 1 0 1 1 0 8 0 vmmpekpl 168 36208 0 36143 4 0 4 4 0 8 0 vmmpepl 168 259555 0 257291 207 71 136 136 0 357 25 vmsppl 464 4061 0 4036 5 0 5 5 0 8 0 rwobjpl 56 75166 0 67560 114 5 109 109 0 8 0 pdppl 4096 8132 0 8072 290 222 68 80 0 8 8 pvpl 32 1379706 0 1359997 423 205 218 362 0 265 43 pmappl 248 4061 0 4036 3 0 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1266 0 382 26 0 26 26 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace witness_checkorder(fffffd806efa1010,9,0) at witness_checkorder+0x1ec sys/kern/subr_witness.c:794 mtx_enter(fffffd806efa1000) at mtx_enter+0x3e sys/kern/kern_lock.c:265 knote_remove(ffff8000211d8ab8,fffffd806efa1000,fffffd806efa1088,4,0) at knote_remove+0x20d sys/kern/kern_event.c:1881 knote_fdclose(ffff8000211d8ab8,4) at knote_fdclose+0xae sys/kern/kern_event.c:1934 fdfree(ffff8000211d8ab8) at fdfree+0xdf sys/kern/kern_descrip.c:1196 exit1(ffff8000211d8ab8,0,0,1) at exit1+0x3e4 sys/kern/kern_exit.c:206 sys_exit(ffff8000211d8ab8,ffff800025d3d120,ffff800025d3d170) at sys_exit+0x1a sys/kern/kern_exit.c:89 syscall(ffff800025d3d1f0) at syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline] syscall(ffff800025d3d1f0) at syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x743d86004fb0, count: -9 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1e: addq $0x8,%rsp x86_ipi_db(ffff800020d58ff0) at x86_ipi_db+0x1e sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 end of kernel end trace frame: 0xc001d18280, count: 12 ddb{1}> trace x86_ipi_db(ffff800020d58ff0) at x86_ipi_db+0x1e sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 end of kernel end trace frame: 0xc001d18280, count: -3