witness: lock order reversal: 1st 0xffff80003abfaee0 fdlock (&newfdp->fd_fd.fd_lock) 2nd 0xfffffd806e1a7340 inode (&ip->i_lock) lock order [1] fdlock (&newfdp->fd_fd.fd_lock) -> [2] inode (&ip->i_lock) lock order data 0xffffffff833525b3 -> 0xffffffff8334590b is missing lock order [2] inode (&ip->i_lock) -> [3] sbufrcv (&so->so_rcv.sb_lock) #0 rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 #1 sblock+0xb6 sys/kern/uipc_socket2.c:536 #2 soreceive+0x27d sys/kern/uipc_socket.c:870 #3 fifo_read+0x117 sys/miscfs/fifofs/fifo_vnops.c:264 #4 VOP_READ+0x101 sys/kern/vfs_vops.c:227 #5 vn_rdwr+0x15b sys/kern/vfs_vnops.c:-1 #6 vndsetcred+0xa1 sys/dev/vnd.c:685 #7 vndioctl+0xdfb sys/dev/vnd.c:486 #8 VOP_IOCTL+0xac sys/kern/vfs_vops.c:264 #9 vn_ioctl+0xf8 sys/kern/vfs_vnops.c:531 #10 sys_ioctl+0x674 sys/kern/sys_generic.c:-1 #11 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #11 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:746 #12 Xsyscall+0x128 lock order [3] sbufrcv (&so->so_rcv.sb_lock) -> [1] fdlock (&newfdp->fd_fd.fd_lock) #0 rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 #1 unp_externalize+0x3cf sys/kern/uipc_usrreq.c:1074 #2 soreceive+0xc24 sys/kern/uipc_socket.c:1009 #3 recvit+0x40b sys/kern/uipc_syscalls.c:1078 #4 sys_recvmsg+0x1bf sys/kern/uipc_syscalls.c:878 #5 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #5 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:746 #6 Xsyscall+0x128 Stopped at db_enter+0x25: addq $0x8,%rsp ddb{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic the kernel did not panic ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 witness_checkorder(fffffd806e1a7340,9,0) at witness_checkorder+0x10b9 sys/kern/subr_witness.c:-1 rw_do_enter_write(fffffd806e1a7328,1) at rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 rrw_enter(fffffd806e1a7328,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 VOP_LOCK(fffffd806e1a6a68,2001) at VOP_LOCK+0xa3 sys/kern/vfs_vops.c:527 vn_lock(fffffd806e1a6a68,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vn_closefile(fffffd806b99f358,ffff80003b0087e8) at vn_closefile+0x111 vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b99f358,ffff80003b0087e8) at vn_closefile+0x111 sys/kern/vfs_vnops.c:615 fdrop(fffffd806b99f358,ffff80003b0087e8) at fdrop+0x121 sys/kern/kern_descrip.c:1280 knote_remove(ffff80003b0087e8,fffffd8073b5b620,fffffd8073b5b6b0,3,0) at knote_remove+0x449 sys/kern/kern_event.c:2168 knote_fdclose(ffff80003b0087e8,3) at knote_fdclose+0xf9 sys/kern/kern_event.c:2203 fdrelease(ffff80003b0087e8,3) at fdrelease+0xf9 sys/kern/kern_descrip.c:760 syscall(ffff80003c4553d0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c4553d0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:746 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x5c39b5c4e00, count: -13 ddb{0}> show registers rdi 0 rsi 0x80000 acpi_pdirpa+0x6be71 rbp 0xffff80003c454ee0 rbx 0 rdx 0xffff80000149e940 rcx 0xffff80003b0087e8 rax 0x7ffff acpi_pdirpa+0x6be70 r8 0xffff80003c454dc0 r9 0x8080808080808080 r10 0x2dfb48f8b08601ff r11 0xd58e72687a96149f r12 0xfffffd8003efac80 r13 0xfffffd80046e74e8 r14 0x3 r15 0xffffffff833e2b64 substchar+0xf1da rip 0xffffffff831577a5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003c454ed0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=255960 pid=66407 tcnt=3 stat=onproc flags process=0 proc=4000000 runpri=32, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80003b0082b8,0xffff80003b008030 process=0xffff80002a3cc4e8 user=0xffff80003c450000, vmspace=0xfffffd806b9ac3e8 estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 66407 142477 25415 0 2 0 syz-executor *66407 255960 25415 0 7 0x4000000 syz-executor 66407 431886 25415 0 3 0x4000080 fsleep syz-executor 90821 440795 14487 0 2 0 syz-executor 90821 206896 14487 0 3 0x4000000 biowait syz-executor 90821 277523 14487 0 3 0x4000000 inode syz-executor 67938 208555 53878 0 7 0 syz-executor 67938 439382 53878 0 2 0x4000000 syz-executor 76113 123912 65128 0 2 0 syz-executor 76113 508749 65128 0 3 0x4000080 ttyout syz-executor 20295 40906 19219 0 3 0x80 nanoslp syz-executor 20295 73514 19219 0 3 0x4000080 fsleep syz-executor 20295 285130 19219 0 3 0x4000080 ttyin syz-executor 53878 340168 27452 0 3 0x82 nanoslp syz-executor 14487 31306 27452 0 3 0x82 nanoslp syz-executor 16253 238364 1 0 3 0x100083 ttyopn getty 1386 409686 27452 0 3 0x82 piperd syz-executor 25415 409590 27452 0 3 0x82 nanoslp syz-executor 97306 374477 0 0 3 0x14200 bored sosplice 98981 253800 27452 0 3 0x82 nanoslp syz-executor 95151 338681 27452 0 2 0x2 syz-executor 19219 48468 27452 0 3 0x82 nanoslp syz-executor 65128 362038 27452 0 3 0x82 nanoslp syz-executor 27452 416696 54934 0 2 0x2 syz-executor 54934 147276 34633 0 3 0x10008a sigsusp ksh 34633 523416 45121 0 3 0x98 kqread sshd-session 45121 397088 24338 0 3 0x92 kqread sshd-session 24338 284499 1 0 3 0x88 kqread sshd 63381 52898 69345 74 3 0x1100092 bpf pflogd 69345 250208 1 0 3 0x80 sbwait pflogd 64801 214690 84687 73 3 0x1100090 kqread syslogd 84687 506321 1 0 3 0x100082 sbwait syslogd 85466 354138 1 0 3 0x100080 kqread resolvd 79606 507347 11145 77 3 0x100092 kqread dhcpleased 88853 479156 11145 77 3 0x100092 kqread dhcpleased 11145 304358 1 0 3 0x80 kqread dhcpleased 65133 430098 0 0 3 0x14200 bored smr 59903 124306 0 0 3 0x14200 pgzero zerothread 56865 129155 0 0 3 0x14200 aiodoned aiodoned 84534 120542 0 0 3 0x14200 syncer update 77840 55800 0 0 3 0x14200 cleaner cleaner 86077 426562 0 0 3 0x14200 reaper reaper 14984 453458 0 0 3 0x14200 pgdaemon pagedaemon 35016 242871 0 0 3 0x14200 bored viomb 40933 389009 0 0 3 0x40014200 acpi0 acpi0 80405 299436 0 0 3 0x40014200 idle1 41957 24743 0 0 3 0x14200 bored softnet1 64851 245258 0 0 3 0x14200 bored softnet0 999 60443 0 0 3 0x14200 bored systqmp 85395 213026 0 0 3 0x14200 bored systq 6470 330622 0 0 3 0x14200 tmoslp softclockmp 75327 186504 0 0 3 0x40014200 tmoslp softclock 41364 450237 0 0 3 0x40014200 idle0 1 485060 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{0}> show all locks Process 66407 (syz-executor) thread 0xffff80003b0087e8 (255960) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83915fc0) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 vn_closefile+0x41 sys/kern/vfs_vnops.c:608 #2 fdrop+0x121 sys/kern/kern_descrip.c:1280 #3 knote_remove+0x449 sys/kern/kern_event.c:2168 #4 knote_fdclose+0xf9 sys/kern/kern_event.c:2203 #5 fdrelease+0xf9 sys/kern/kern_descrip.c:760 #6 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #6 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:746 #7 Xsyscall+0x128 exclusive rwlock fdlock r = 0 (0xffff80003abfaee0) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 sys_close+0xd0 sys/kern/kern_descrip.c:778 #3 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #3 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:746 #4 Xsyscall+0x128 Process 90821 (syz-executor) thread 0xffff80003b0082b8 (206896) exclusive rrwlock inode r = 0 (0xfffffd806e21a360) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xa3 sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570 #5 vn_write+0x18f sys/kern/vfs_vnops.c:405 #6 dofilewritev+0x242 sys/kern/sys_generic.c:380 #7 sys_write+0xa2 sys/kern/sys_generic.c:300 #8 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #8 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:746 #9 Xsyscall+0x128 Process 90821 (syz-executor) thread 0xffff80003b008020 (277523) exclusive rrwlock inode r = 0 (0xfffffd806e0a3668) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xa3 sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570 #5 vfs_lookup+0x11c sys/kern/vfs_lookup.c:-1 #6 namei+0x7ca sys/kern/vfs_lookup.c:250 #7 domknodat+0xb4 sys/kern/vfs_syscalls.c:1592 #8 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #8 syscall+0xb17 sys/arch/amd64/amd64/trap.c:746 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10223 11038K 12685K 166960K 14641 0 pcb 17 18K 32K 166960K 504 0 rtable 157 9K 10K 166960K 832 0 pf 29 16K 67485K 166960K 305 0 ifaddr 28 5K 8K 166960K 166 0 ifgroup 43 2K 2K 166960K 285 0 sysctl 4 1K 9K 166960K 25 0 counters 62 36K 38K 166960K 312 0 ioctlops 0 0K 8K 166960K 1959 0 iov 1 2K 28K 166960K 129 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1516 95K 96K 166960K 3116 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 9K 166960K 29 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 214 0 dirhash 12 2K 2K 166960K 48 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 17 61K 89K 166960K 1881 0 sigio 0 0K 0K 166960K 36 0 proc 74 115K 164K 166960K 847 0 subproc 72 4K 4K 166960K 118 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 196 0 in_multi 52 3K 7K 166960K 242 0 ether_multi 1 0K 0K 166960K 28 0 mrt 1 0K 0K 166960K 20 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 265 1182K 1182K 166960K 265 0 exec 0 0K 1K 166960K 710 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 3 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 241 159K 177K 166960K 18543 0 UVM aobj 131 4K 4K 166960K 139 0 pinsyscall 42 84K 102K 166960K 3131 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 1K 166960K 122 0 NDP 9 0K 2K 166960K 118 0 temp 143 8657K 8728K 166960K 78920 0 kqueue 14 22K 32K 166960K 381 0 SYN cache 2 8K 16K 166960K 3 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 26 0 0 1 0 1 1 0 8 0 rtpcb 120 269 0 266 2 0 2 2 0 8 1 rtentry 176 262 0 206 5 0 5 5 0 8 0 unpcb 144 1719 0 1700 16 10 6 9 0 8 5 syncache 336 8 0 8 3 2 1 1 0 8 1 tcpqe 32 6 0 6 2 1 1 1 0 8 1 tcpcb 736 620 0 615 11 2 9 10 0 8 8 arp 136 24 0 14 1 0 1 1 0 8 0 inpcb 328 2139 0 2129 18 8 10 10 0 8 8 nd6 152 32 0 23 1 0 1 1 0 8 0 pkpcb 40 16 0 16 4 3 1 1 0 8 1 kcovpl 48 13 0 5 1 0 1 1 0 8 0 mppekey 1024 2 0 2 2 1 1 1 0 8 1 ppxss 1192 96 0 96 1 0 1 1 0 8 1 pppxif 1504 14 0 14 2 1 1 1 0 8 1 pfstscr 40 1 0 1 1 1 0 1 0 8 0 pffrag 232 14 0 3 1 0 1 1 0 482 0 pffrnode 88 11 0 1 1 0 1 1 0 8 0 pffrent 40 40 0 28 1 0 1 1 0 8 0 pfosfp 40 1430 0 1006 5 0 5 5 0 8 0 pfosfpen 112 1430 0 714 21 0 21 21 0 8 0 pfrktable 1344 4 0 4 3 2 1 1 0 8 1 pfstitem 24 65 0 28 1 0 1 1 0 8 0 pfstkey 128 67 0 30 2 0 2 2 0 8 0 pfstate 384 66 0 29 7 0 7 7 0 8 0 pfrule 1344 26 0 20 2 1 1 2 0 8 0 rttmr 136 4 0 4 3 3 0 1 0 8 0 art_heap8 4096 4 0 0 4 0 4 4 0 8 0 art_heap4 256 941 0 692 30 5 25 30 0 8 8 art_table 40 945 0 692 5 0 5 5 0 8 0 art_node 32 261 0 212 2 1 1 2 0 8 0 sysvmsgpl 40 7 0 6 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 173 0 163 1 0 1 1 0 8 0 shmpl 112 136 0 8 4 0 4 4 0 8 0 dirhash 1024 42 0 25 3 0 3 3 0 8 0 dino2pl 256 4797 0 3285 96 0 96 96 0 8 0 ffsino 296 4797 0 3285 118 0 118 118 0 8 0 nchpl 144 7373 0 5667 64 0 64 64 0 8 0 rtmask 32 20 0 20 3 2 1 1 0 8 1 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 26177 0 26176 3 2 1 2 0 8 0 percpumem 16 171 0 125 1 0 1 1 0 8 0 kstatmem 264 184 0 164 5 2 3 3 0 8 1 scsiplug 72 5 0 5 2 2 0 1 0 8 0 scxspl 216 42597 0 42596 11 10 1 8 1 8 0 plimitpl 152 437 0 416 1 0 1 1 0 8 0 sigapl 424 2197 0 2149 7 1 6 7 0 8 0 knotepl 120 613 0 0 18 0 18 18 0 8 0 kqueuepl 224 727 0 716 6 4 2 3 0 8 1 pipepl 344 320 0 293 4 1 3 4 0 8 0 fdescpl 528 2163 0 2132 3 0 3 3 0 8 0 filepl 160 14743 0 14516 34 15 19 22 0 8 8 lockfpl 104 944 0 942 1 0 1 1 0 8 0 lockfspl 48 358 0 356 1 0 1 1 0 8 0 sessionpl 144 30 0 21 1 0 1 1 0 8 0 pgrppl 48 59 0 42 1 0 1 1 0 8 0 ucredpl 104 2381 0 2368 2 1 1 2 0 8 0 zombiepl 144 2151 0 2149 1 0 1 1 0 8 0 processpl 1232 2197 0 2149 5 0 5 5 0 8 0 procpl 664 4993 0 4937 8 2 6 7 0 8 0 sosppl 168 10 0 10 2 2 0 1 0 8 0 sockpl 752 4290 0 4258 55 42 13 24 0 8 8 mcl64k 65536 10 0 0 2 0 2 2 0 8 0 mcl16k 16384 15 0 0 2 0 2 2 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 9 0 0 2 0 2 2 0 8 0 mcl4k 4096 131 0 0 17 0 17 17 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 37 0 0 5 0 5 5 0 8 0 mtagpl 96 7 0 0 1 0 1 1 0 8 0 mbufpl 256 1188 0 0 75 0 75 75 0 8 0 bufpl 280 17708 0 11565 439 0 439 439 0 8 0 anonpl 32 12737 0 0 103 0 103 103 0 246 0 amapchunkpl 152 63566 0 63054 52 21 31 33 0 158 9 amappl16 200 6839 0 6794 42 31 11 29 0 8 1 amappl15 192 9 0 9 1 1 0 1 0 8 0 amappl14 184 128 0 116 1 0 1 1 0 8 0 amappl13 176 6 0 5 1 0 1 1 0 8 0 amappl12 168 2901 0 2870 3 1 2 2 0 8 0 amappl11 160 63 0 49 1 0 1 1 0 8 0 amappl10 152 9 0 8 3 2 1 1 0 8 0 amappl9 144 249 0 249 1 1 0 1 0 8 0 amappl8 136 27 0 25 1 0 1 1 0 8 0 amappl7 128 157 0 144 1 0 1 1 0 8 0 amappl6 120 227 0 223 1 0 1 1 0 8 0 amappl5 112 178 0 167 1 0 1 1 0 8 0 amappl4 104 346 0 326 1 0 1 1 0 8 0 amappl3 96 11160 0 11055 3 0 3 3 0 8 0 amappl2 88 2411 0 2333 2 0 2 2 0 8 0 amappl1 80 15704 0 15104 14 0 14 14 0 8 0 amappl 88 17458 0 17289 5 0 5 5 0 92 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 2 0 1 1 0 1 1 0 8 0 dma512 512 1 0 1 1 1 0 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 254 0 254 2 2 0 1 0 8 0 dma64 64 8 0 8 2 2 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 72 138 0 8 3 0 3 3 0 8 0 uaddrrnd 24 2163 0 2132 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2163 0 2132 1 0 1 1 0 8 0 vmmpekpl 168 17677 0 17630 3 0 3 3 0 8 0 vmmpepl 168 138378 0 136361 116 19 97 111 0 357 0 vmsppl 488 2162 0 2132 5 0 5 5 0 8 0 rwobjpl 80 41866 0 34852 147 0 147 147 0 8 0 pdppl 4096 4334 0 4264 112 40 72 84 0 8 2 pvpl 32 22938 0 0 185 0 185 185 0 265 0 pmappl 256 2162 0 2132 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 374 0 55 10 0 10 10 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 witness_checkorder(fffffd806e1a7340,9,0) at witness_checkorder+0x10b9 sys/kern/subr_witness.c:-1 rw_do_enter_write(fffffd806e1a7328,1) at rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 rrw_enter(fffffd806e1a7328,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 VOP_LOCK(fffffd806e1a6a68,2001) at VOP_LOCK+0xa3 sys/kern/vfs_vops.c:527 vn_lock(fffffd806e1a6a68,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vn_closefile(fffffd806b99f358,ffff80003b0087e8) at vn_closefile+0x111 vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b99f358,ffff80003b0087e8) at vn_closefile+0x111 sys/kern/vfs_vnops.c:615 fdrop(fffffd806b99f358,ffff80003b0087e8) at fdrop+0x121 sys/kern/kern_descrip.c:1280 knote_remove(ffff80003b0087e8,fffffd8073b5b620,fffffd8073b5b6b0,3,0) at knote_remove+0x449 sys/kern/kern_event.c:2168 knote_fdclose(ffff80003b0087e8,3) at knote_fdclose+0xf9 sys/kern/kern_event.c:2203 fdrelease(ffff80003b0087e8,3) at fdrelease+0xf9 sys/kern/kern_descrip.c:760 syscall(ffff80003c4553d0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c4553d0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:746 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x5c39b5c4e00, count: -13 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp ddb{1}> trace x86_ipi_db(ffff8000299edff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394 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(ffffffff83915db8) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff83915db8) at __mp_lock+0x199 sys/kern/kern_lock.c:165 syscall(ffff8000367e7860) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] syscall(ffff8000367e7860) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:746 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x78e95e7d5b40, count: -6