witness: lock order reversal: 1st 0xfffffd807c15c630 fdlock (&newfdp->fd_fd.fd_lock) 2nd 0xfffffd806de54818 inode (&ip->i_lock) lock order [1] fdlock (&newfdp->fd_fd.fd_lock) -> [2] inode (&ip->i_lock) lock order data 0xffffffff830c0c97 -> 0xffffffff8304f7ef is missing lock order [2] inode (&ip->i_lock) -> [3] sbufrcv (&so->so_rcv.sb_lock) #0 rw_enter+0x122 #1 sblock+0xb7 sys/kern/uipc_socket2.c:549 #2 soreceive+0x298 sys/kern/uipc_socket.c:877 #3 fifo_read+0x11a sys/miscfs/fifofs/fifo_vnops.c:264 #4 VOP_READ+0x102 sys/kern/vfs_vops.c:227 #5 vn_rdwr+0x15b #6 vndsetcred+0xa1 sys/dev/vnd.c:684 #7 vndioctl+0xe6c sys/dev/vnd.c:485 #8 VOP_IOCTL+0xac sys/kern/vfs_vops.c:264 #9 vn_ioctl+0xf6 sys/kern/vfs_vnops.c:525 #10 sys_ioctl+0x67c #11 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] #11 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #12 Xsyscall+0x128 lock order [3] sbufrcv (&so->so_rcv.sb_lock) -> [1] fdlock (&newfdp->fd_fd.fd_lock) #0 rw_enter_write+0x7a sys/kern/kern_rwlock.c:128 #1 unp_externalize+0x3e4 sys/kern/uipc_usrreq.c:1072 #2 soreceive+0xd3e sys/kern/uipc_socket.c:1022 #3 recvit+0x40a sys/kern/uipc_syscalls.c:1082 #4 sys_recvmsg+0x1bf sys/kern/uipc_syscalls.c:882 #5 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] #5 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #6 Xsyscall+0x128 Stopped at db_enter+0x25: addq $0x8,%rsp ddb{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic the kernel did not panic ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(fffffd806de54818,9,0) at witness_checkorder+0x1024 rw_enter(fffffd806de54808,1) at rw_enter+0x122 rrw_enter(fffffd806de54808,1) at rrw_enter+0xbe sys/kern/kern_rwlock.c:464 VOP_LOCK(fffffd806de50cf0,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd806de50cf0,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:564 vn_closefile(fffffd8058a18bf8,ffff8000311b4cf8) at vn_closefile+0x111 vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8058a18bf8,ffff8000311b4cf8) at vn_closefile+0x111 sys/kern/vfs_vnops.c:609 fdrop(fffffd8058a18bf8,ffff8000311b4cf8) at fdrop+0x126 sys/kern/kern_descrip.c:1274 knote_remove(ffff8000311b4cf8,fffffd807e48f360,fffffd807e48f3e8,3,0) at knote_remove+0x403 sys/kern/kern_event.c:1899 knote_fdclose(ffff8000311b4cf8,3) at knote_fdclose+0xf9 sys/kern/kern_event.c:1934 fdrelease(ffff8000311b4cf8,3) at fdrelease+0xf6 sys/kern/kern_descrip.c:758 syscall(ffff80002a13c360) at syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] syscall(ffff80002a13c360) at syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xa4430d49830, count: -13 ddb{1}> show registers rdi 0 rsi 0x40000 acpi_pdirpa+0x2be71 rbp 0xffff80002a13be20 rbx 0xffffffff83061629 pp_r600_decoded_lanes+0x34594 rdx 0xffff8000011ade00 rcx 0xffff8000311b4cf8 rax 0x3ffff acpi_pdirpa+0x2be70 r8 0xffff80002a13bd00 r9 0x8080808080808080 r10 0x7cc0e2ca42d05714 r11 0x3e2428f0a3761356 r12 0xfffffd80042a1450 r13 0xfffffd8003ab7dc0 r14 0x3 r15 0xffffffff rip 0xffffffff816cefe5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a13be10 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor) tid=429109 pid=33447 tcnt=3 stat=onproc flags process=8000000 proc=4000000 runpri=32, usrpri=86, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000311b47e8,0xffffffff834f9740 process=0xffff80002d771b18 user=0xffff80002a137000, vmspace=0xfffffd8059a691c8 estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 92807 175670 95381 0 7 0x8000000 syz-executor 92807 232614 95381 0 3 0xc000000 biowait syz-executor 5572 409861 44044 0 2 0x8000000 syz-executor 33447 168128 47682 0 2 0x8000000 syz-executor 33447 341412 47682 0 3 0xc000080 piperd syz-executor *33447 429109 47682 0 7 0xc000000 syz-executor 54584 403162 20706 0 2 0x8000000 syz-executor 54584 147277 20706 0 3 0xc000080 ttyopn syz-executor 54584 463387 20706 0 3 0xc000080 fsleep syz-executor 10476 8688 81077 0 3 0x8000080 nanoslp syz-executor 10476 13979 81077 0 3 0xc000080 kqpoll syz-executor 10476 31397 81077 0 3 0xc000080 fsleep syz-executor 68560 18591 1 0 3 0x18100083 ttyin getty 74305 172316 48640 0 3 0x8000082 piperd syz-executor 20706 199009 48640 0 3 0x8000082 nanoslp syz-executor 95381 420632 48640 0 3 0x8000082 nanoslp syz-executor 28356 263171 48640 0 3 0x8000082 nanoslp syz-executor 47682 173360 48640 0 3 0x8000082 nanoslp syz-executor 36350 236586 48640 0 3 0x8000082 piperd syz-executor 44044 183 48640 0 3 0x8000082 nanoslp syz-executor 81077 92646 48640 0 3 0x8000082 nanoslp syz-executor 65896 163026 0 0 3 0x14280 nfsidl nfsio 2499 515100 0 0 3 0x14280 nfsidl nfsio 31216 230606 0 0 3 0x14280 nfsidl nfsio 46879 295260 0 0 3 0x14280 nfsidl nfsio 81898 66197 0 0 3 0x14280 nfsidl nfsio 47629 80841 0 0 3 0x14280 nfsidl nfsio 32708 307457 0 0 3 0x14280 nfsidl nfsio 11593 123322 0 0 3 0x14280 nfsidl nfsio 38208 158194 0 0 3 0x14280 nfsidl nfsio 5650 283623 0 0 3 0x14280 nfsidl nfsio 45582 459850 0 0 3 0x14280 nfsidl nfsio 31564 220283 0 0 3 0x14280 nfsidl nfsio 32027 491312 0 0 3 0x14280 nfsidl nfsio 19817 426602 0 0 3 0x14280 nfsidl nfsio 25342 279565 0 0 3 0x14280 nfsidl nfsio 84240 75012 0 0 3 0x14280 nfsidl nfsio 2705 43040 0 0 3 0x14280 nfsidl nfsio 71464 238262 0 0 3 0x14280 nfsidl nfsio 93541 96237 0 0 3 0x14280 nfsidl nfsio 99923 239502 0 0 3 0x14280 nfsidl nfsio 33298 328448 0 0 3 0x14200 bored sosplice 48640 5184 31714 0 2 0x8000002 syz-executor 31714 145670 75121 0 3 0x810008a sigsusp ksh 75121 407348 73712 0 3 0x18000098 kqread sshd-session 73712 152475 85774 0 3 0x18000092 kqread sshd-session 85774 312052 1 0 3 0x18000088 kqread sshd 15625 481688 83003 74 3 0x19100092 bpf pflogd 83003 213133 1 0 3 0x18000080 sbwait pflogd 63019 349093 88064 73 3 0x19100090 kqread syslogd 88064 492157 1 0 3 0x18100082 sbwait syslogd 76605 286076 1 0 3 0x18100080 kqread resolvd 26547 482381 51063 77 3 0x18100092 kqread dhcpleased 58139 295652 51063 77 3 0x18100092 kqread dhcpleased 51063 119240 1 0 3 0x18000080 kqread dhcpleased 43652 342887 0 0 3 0x14200 bored smr 83761 46600 0 0 2 0x14200 zerothread 36959 65349 0 0 3 0x14200 aiodoned aiodoned 38366 492261 0 0 3 0x14200 syncer update 22436 444464 0 0 3 0x14200 cleaner cleaner 43648 283418 0 0 3 0x14200 reaper reaper 45985 451779 0 0 3 0x14200 pgdaemon pagedaemon 92811 375050 0 0 3 0x14200 bored viomb 163 262762 0 0 3 0x40014200 acpi0 acpi0 5488 346241 0 0 3 0x40014200 idle1 60297 473838 0 0 3 0x14200 bored softnet3 21973 453185 0 0 3 0x14200 bored softnet2 80927 204666 0 0 3 0x14200 bored softnet1 9875 237175 0 0 3 0x14200 bored softnet0 57886 379474 0 0 3 0x14200 bored systqmp 70901 105992 0 0 3 0x14200 bored systq 23787 331208 0 0 3 0x14200 tmoslp softclockmp 5667 286750 0 0 3 0x40014200 tmoslp softclock 84048 32697 0 0 3 0x40014200 idle0 1 165879 0 0 3 0x8000082 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 92807 (syz-executor) thread 0xffff8000311b47e8 (232614) exclusive rrwlock inode r = 0 (0xfffffd807bc436f8) #0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151 #1 rw_enter+0x41b sys/kern/kern_rwlock.c:309 #2 rrw_enter+0xbe sys/kern/kern_rwlock.c:464 #3 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:564 #5 vn_write+0x18d sys/kern/vfs_vnops.c:405 #6 dofilewritev+0x23c sys/kern/sys_generic.c:375 #7 sys_write+0xa2 sys/kern/sys_generic.c:295 #8 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] #8 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #9 Xsyscall+0x128 Process 33447 (syz-executor) thread 0xffff8000311b4cf8 (429109) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff834f5130) #0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151 #1 vn_closefile+0x41 sys/kern/vfs_vnops.c:602 #2 fdrop+0x126 sys/kern/kern_descrip.c:1274 #3 knote_remove+0x403 sys/kern/kern_event.c:1899 #4 knote_fdclose+0xf9 sys/kern/kern_event.c:1934 #5 fdrelease+0xf6 sys/kern/kern_descrip.c:758 #6 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] #6 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #7 Xsyscall+0x128 exclusive rwlock fdlock r = 0 (0xfffffd807c15c630) #0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151 #1 sys_close+0xc4 sys/kern/kern_descrip.c:776 #2 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] #2 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #3 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10207 10227K 10746K 166960K 14041 0 pcb 17 12K 12K 166960K 244 0 rtable 220 7K 7K 166960K 2761 0 pf 37 10K 11K 166960K 266 0 ifaddr 49 17K 17K 166960K 403 0 ifgroup 64 2K 2K 166960K 450 0 sysctl 3 0K 1K 166960K 7 0 counters 68 36K 37K 166960K 282 0 ioctlops 0 0K 4K 166960K 1627 0 iov 0 0K 16K 166960K 76 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1374 86K 87K 166960K 3395 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 2K 6K 166960K 25 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 84 0 dirhash 15 2K 3K 166960K 42 0 ACPI 1697 195K 286K 166960K 12548 0 file desc 16 57K 97K 166960K 3301 0 sigio 0 0K 0K 166960K 36 0 proc 70 91K 164K 166960K 2753 0 subproc 104 6K 7K 166960K 1105 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 240 0 in_multi 99 7K 7K 166960K 1002 0 ether_multi 1 0K 0K 166960K 23 0 mrt 1 0K 0K 166960K 10 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 103 466K 466K 166960K 103 0 exec 0 0K 1K 166960K 1531 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 242 74K 92K 166960K 26067 0 UVM aobj 47 2K 2K 166960K 48 0 pinsyscall 41 82K 106K 166960K 6358 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 125 0 NDP 14 0K 1K 166960K 289 0 temp 77 6816K 14750K 166960K 107086 0 kqueue 14 22K 29K 166960K 213 0 SYN cache 2 16K 16K 166960K 2 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 24 0 0 1 0 1 1 0 8 0 rtpcb 120 306 0 303 1 0 1 1 0 8 0 rtentry 112 979 0 879 5 2 3 4 0 8 0 unpcb 144 928 0 911 6 4 2 2 0 8 1 syncache 336 4 0 4 2 2 0 1 0 8 0 tcpcb 808 330 0 326 3 2 1 2 0 8 0 arp 120 176 0 157 1 0 1 1 0 8 0 inpcb 384 1660 0 1650 11 9 2 2 0 8 0 nd6 136 261 0 235 1 0 1 1 0 8 0 pkpcb 40 7 0 7 2 2 0 1 0 8 0 kcovpl 48 85 0 77 1 0 1 1 0 8 0 ppxss 1168 25 0 25 5 5 0 1 0 8 0 pffrag 232 11 0 9 2 1 1 1 0 482 0 pffrnode 88 11 0 9 2 1 1 1 0 8 0 pffrent 40 71 0 69 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 24 197 0 155 1 0 1 1 0 8 0 pfstkey 128 197 0 155 2 0 2 2 0 8 0 pfstate 376 197 0 155 7 2 5 6 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 3873 0 3420 34 5 29 29 0 8 0 art_table 32 3874 0 3420 4 0 4 4 0 8 0 art_node 16 972 0 882 1 0 1 1 0 8 0 sysvmsgpl 40 11 0 1 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 81 0 71 1 0 1 1 0 8 0 shmpl 112 45 0 1 2 0 2 2 0 8 0 dirhash 1024 37 0 18 3 0 3 3 0 8 0 dino2pl 256 4663 0 2998 105 0 105 105 0 8 0 ffsino 272 4663 0 2998 112 0 112 112 0 8 0 nchpl 144 7548 0 6924 67 31 36 67 0 8 8 uvmvnodes 80 6471 0 0 133 0 133 133 0 8 0 vnodes 216 6471 0 0 360 0 360 360 0 8 0 namei 1024 28387 0 28387 5 4 1 2 0 8 1 percpumem 16 155 0 107 1 0 1 1 0 8 0 vcpupl 3904 8 0 0 1 0 1 1 0 8 0 vmpool 696 30 0 22 3 2 1 1 0 8 0 kstatmem 264 242 0 214 3 0 3 3 0 8 0 scsiplug 72 7 0 7 2 2 0 1 0 8 0 scxspl 216 72288 0 72287 14 13 1 8 1 8 0 plimitpl 152 299 0 281 1 0 1 1 0 8 0 sigapl 424 3470 0 3401 11 2 9 9 0 8 0 futexpl 64 20966 0 20964 10 9 1 1 0 8 0 knotepl 120 640 0 0 18 0 18 18 0 8 0 kqueuepl 216 341 0 330 1 0 1 1 0 8 0 pipepl 320 449 0 421 3 0 3 3 0 8 0 fdescpl 496 3430 0 3400 8 3 5 6 0 8 0 filepl 152 12686 0 12435 14 3 11 11 0 8 0 lockfpl 104 590 0 588 1 0 1 1 0 8 0 lockfspl 48 245 0 243 1 0 1 1 0 8 0 sessionpl 144 101 0 92 1 0 1 1 0 8 0 pgrppl 48 220 0 203 1 0 1 1 0 8 0 ucredpl 104 1861 0 1848 1 0 1 1 0 8 0 zombiepl 144 3402 0 3401 1 0 1 1 0 8 0 processpl 1152 3470 0 3401 7 1 6 6 0 8 0 procpl 648 5822 0 5746 11 3 8 8 0 8 0 srpgc 96 8 0 8 4 4 0 1 0 8 0 sosppl 168 7 0 7 4 4 0 1 0 8 0 sockpl 664 2903 0 2874 13 8 5 5 0 8 2 mcl64k 65536 27 0 0 3 0 3 3 0 8 0 mcl16k 16384 19 0 0 3 0 3 3 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 23 0 0 2 0 2 2 0 8 0 mcl8k 8192 22 0 0 3 0 3 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k 2048 285 0 0 32 0 32 32 0 8 0 mtagpl 96 29 0 0 1 0 1 1 0 8 0 mbufpl 256 1154 0 0 63 0 63 63 0 8 0 bufpl 280 21301 0 11935 670 0 670 670 0 8 0 anonpl 24 485500 0 478319 136 66 70 105 0 185 0 amapchunkpl 152 86329 0 85725 73 43 30 52 0 158 1 amappl16 200 9510 0 9390 85 65 20 20 0 8 3 amappl15 192 5 0 5 1 1 0 1 0 8 0 amappl14 184 270 0 258 1 0 1 1 0 8 0 amappl13 176 5 0 5 1 1 0 1 0 8 0 amappl12 168 5285 0 5256 4 2 2 3 0 8 0 amappl11 160 55 0 41 1 0 1 1 0 8 0 amappl10 152 12 0 12 1 1 0 1 0 8 0 amappl9 144 148 0 147 1 0 1 1 0 8 0 amappl8 136 26 0 23 1 0 1 1 0 8 0 amappl7 128 260 0 248 1 0 1 1 0 8 0 amappl6 120 927 0 926 1 0 1 1 0 8 0 amappl5 112 446 0 435 1 0 1 1 0 8 0 amappl4 104 545 0 525 1 0 1 1 0 8 0 amappl3 96 17115 0 17007 6 2 4 4 0 8 0 amappl2 88 1688 0 1625 2 0 2 2 0 8 0 amappl1 80 21893 0 21306 19 5 14 15 0 8 0 amappl 88 25067 0 24895 6 1 5 5 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 47 0 1 1 0 1 1 0 8 0 uaddrrnd 24 3460 0 3422 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3460 0 3422 1 0 1 1 0 8 0 vmmpekpl 168 25711 0 25659 6 2 4 4 0 8 0 vmmpepl 168 207395 0 205445 134 32 102 102 0 357 2 vmsppl 440 3459 0 3422 7 2 5 5 0 8 0 rwobjpl 56 61071 0 53509 116 5 111 111 0 8 0 pdppl 4096 6927 0 6852 210 130 80 87 0 8 5 pvpl 32 50044 0 0 405 1 404 404 0 265 0 pmappl 248 3459 0 3422 3 0 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 590 0 150 13 0 13 13 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp ddb{0}> trace x86_ipi_db(ffffffff8343eff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 __mp_lock(ffffffff834f4f28) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff834f4f28) at __mp_lock+0x192 sys/kern/kern_lock.c:144 intr_handler(ffff80002d76e320,ffff800000069c00) at intr_handler+0xe1 sys/arch/amd64/amd64/intr.c:553 Xintr_ioapic_edge16_untramp() at Xintr_ioapic_edge16_untramp+0x18f __mp_lock(ffffffff834f4f28) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff834f4f28) at __mp_lock+0x192 sys/kern/kern_lock.c:144 intr_handler(ffff80002d76e480,ffff80000006c000) at intr_handler+0xe1 sys/arch/amd64/amd64/intr.c:553 Xintr_ioapic_edge25_untramp() at Xintr_ioapic_edge25_untramp+0x18f __mp_lock(ffffffff834f4f28) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff834f4f28) at __mp_lock+0x192 sys/kern/kern_lock.c:144 intr_handler(ffff80002d76e5e0,ffff80000006bc00) at intr_handler+0xe1 sys/arch/amd64/amd64/intr.c:553 Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f end of kernel end trace frame: 0x7c9388922770, count: -12 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x25: addq $0x8,%rsp ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(fffffd806de54818,9,0) at witness_checkorder+0x1024 rw_enter(fffffd806de54808,1) at rw_enter+0x122 rrw_enter(fffffd806de54808,1) at rrw_enter+0xbe sys/kern/kern_rwlock.c:464 VOP_LOCK(fffffd806de50cf0,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd806de50cf0,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:564 vn_closefile(fffffd8058a18bf8,ffff8000311b4cf8) at vn_closefile+0x111 vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8058a18bf8,ffff8000311b4cf8) at vn_closefile+0x111 sys/kern/vfs_vnops.c:609 fdrop(fffffd8058a18bf8,ffff8000311b4cf8) at fdrop+0x126 sys/kern/kern_descrip.c:1274 knote_remove(ffff8000311b4cf8,fffffd807e48f360,fffffd807e48f3e8,3,0) at knote_remove+0x403 sys/kern/kern_event.c:1899 knote_fdclose(ffff8000311b4cf8,3) at knote_fdclose+0xf9 sys/kern/kern_event.c:1934 fdrelease(ffff8000311b4cf8,3) at fdrelease+0xf6 sys/kern/kern_descrip.c:758 syscall(ffff80002a13c360) at syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline] syscall(ffff80002a13c360) at syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xa4430d49830, count: -13