panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 951 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 56415 49300 77 0x100012 0x1 1 dhcpleased db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8346ab60) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff8341ad1e,ffffffff8341b694,3b7,ffffffff8341b717) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003b0274f0,ffffffff83366099) at refcnt_finalize+0x1db sys/kern/kern_synch.c:952 pppx_if_destroy(0,ffff80003b0274e8) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff80002a2a7c50) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003a8217b0) at spec_close+0x412 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806640e018,2,fffffd80097fb4e0,ffff80002a2a7c50) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156 vn_closefile(fffffd8068aa31e8,ffff80002a2a7c50) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8068aa31e8,ffff80002a2a7c50) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd8068aa31e8,ffff80002a2a7c50) at fdrop+0x126 sys/kern/kern_descrip.c:1267 closef(fffffd8068aa31e8,ffff80002a2a7c50) at closef+0x192 sys/kern/kern_descrip.c:1251 fdfree(ffff80002a2a7c50) at fdfree+0x116 sys/kern/kern_descrip.c:1182 exit1(ffff80002a2a7c50,0,0,1) at exit1+0x59c sys/kern/kern_exit.c:215 sys_exit(ffff80002a2a7c50,ffff80003a821b20,ffff80003a821a70) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff80003a821b10, count: 0 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: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 951 ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8346ab60) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff8341ad1e,ffffffff8341b694,3b7,ffffffff8341b717) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003b0274f0,ffffffff83366099) at refcnt_finalize+0x1db sys/kern/kern_synch.c:952 pppx_if_destroy(0,ffff80003b0274e8) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff80002a2a7c50) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003a8217b0) at spec_close+0x412 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806640e018,2,fffffd80097fb4e0,ffff80002a2a7c50) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156 vn_closefile(fffffd8068aa31e8,ffff80002a2a7c50) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8068aa31e8,ffff80002a2a7c50) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd8068aa31e8,ffff80002a2a7c50) at fdrop+0x126 sys/kern/kern_descrip.c:1267 closef(fffffd8068aa31e8,ffff80002a2a7c50) at closef+0x192 sys/kern/kern_descrip.c:1251 fdfree(ffff80002a2a7c50) at fdfree+0x116 sys/kern/kern_descrip.c:1182 exit1(ffff80002a2a7c50,0,0,1) at exit1+0x59c sys/kern/kern_exit.c:215 sys_exit(ffff80002a2a7c50,ffff80003a821b20,ffff80003a821a70) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003a821b20) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003a821b20) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7dadf8db1940, count: -16 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff80003a821580 rbx 0xffffffff838afddf cpu_info_full_primary+0x2ddf rdx 0 rcx 0xffff80002a2a7c50 rax 0xffffffff838aeff0 cpu_info_full_primary+0x1ff0 r8 0 r9 0x8080808080808080 r10 0x38ec63a21a984878 r11 0x32ac34a4612371bd r12 0xffffffff838afbe0 cpu_info_full_primary+0x2be0 r13 0 r14 0 r15 0x1 rip 0xffffffff82e07565 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003a821570 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=380049 pid=14416 tcnt=0 stat=onproc flags process=1008 proc=2000 runpri=32, usrpri=82, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0xffff80002a2a7c50 scnt=-1 ecnt=1 forw=0xffffffffffffffff, list=0xffff80002a2a7730,0xffff80002a2a6550 process=0xffff80003a819d60 user=0xffff80003a81c000, vmspace=0xfffffd806b9797b8 estcpu=32, cpticks=1, pctcpu=0.1, user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 30962 267972 63004 0 3 0x80 nanoslp syz-executor 30962 390728 63004 0 2 0x4000000 syz-executor 30962 123927 63004 0 3 0x4000080 fsleep syz-executor 40674 221974 33049 0 2 0xc80 syz-executor 40674 40900 33049 0 3 0x4000080 dtread syz-executor 40674 177984 33049 0 3 0x4000080 fsleep syz-executor 57169 254360 18495 0 2 0xc80 syz-executor 57169 454380 18495 0 3 0x4000080 piperd syz-executor 82883 426064 1 0 3 0x100083 ttyin getty 29000 513288 0 0 3 0x14200 acct acct 86016 428010 11254 0 3 0x82 sbwait sshd-session 20274 323226 54395 0 2 0x2 syz-executor 4226 36895 0 0 3 0x14200 bored sosplice 62984 329213 54395 0 3 0x82 wait syz-executor 70517 69932 54395 0 2 0xc82 syz-executor 92814 188851 54395 0 3 0x82 nanoslp syz-executor 49892 481119 54395 0 2 0xc82 syz-executor 33049 16010 54395 0 2 0xc82 syz-executor 63004 94376 54395 0 2 0xc82 syz-executor 18495 239882 54395 0 2 0xc82 syz-executor 54395 477559 85710 0 3 0x82 kqread syz-executor 85710 161797 32577 0 3 0x10008a sigsusp ksh 32577 245834 73066 0 3 0x98 kqread sshd-session 73066 82986 11254 0 3 0x92 kqread sshd-session 11254 273225 1 0 3 0x88 kqread sshd 25297 204640 67893 74 3 0x1100092 bpf pflogd 67893 100489 1 0 3 0x80 sbwait pflogd 65439 398370 1509 73 3 0x1100090 kqread syslogd 1509 421866 1 0 3 0x100082 sbwait syslogd 2570 308902 1 0 3 0x100080 kqread resolvd 49300 56415 46888 77 7 0x100013 dhcpleased 98758 481290 46888 77 3 0x100092 kqread dhcpleased 46888 475099 1 0 3 0x80 kqread dhcpleased 4719 411060 0 0 3 0x14200 bored smr 65429 385138 0 0 3 0x14200 pgzero zerothread 68734 505953 0 0 3 0x14200 aiodoned aiodoned 6030 19657 0 0 3 0x14200 syncer update 79456 363891 0 0 3 0x14200 cleaner cleaner 70669 78566 0 0 3 0x14200 reaper reaper 81036 65071 0 0 3 0x14200 pgdaemon pagedaemon 76699 271455 0 0 3 0x14200 bored viomb 55654 47894 0 0 3 0x40014200 acpi0 acpi0 86902 221948 0 0 3 0x40014200 idle1 51288 313280 0 0 3 0x14200 bored softnet7 57402 395629 0 0 3 0x14200 bored softnet6 26922 305840 0 0 3 0x14200 bored softnet5 20809 317138 0 0 3 0x14200 bored softnet4 34105 25658 0 0 3 0x14200 bored softnet3 2924 55214 0 0 3 0x14200 bored softnet2 28369 298107 0 0 3 0x14200 bored softnet1 49852 379262 0 0 2 0x14200 softnet0 96689 128841 0 0 3 0x14200 smrbar systqmp 96351 284533 0 0 3 0x14200 bored systq 74010 201812 0 0 3 0x14200 tmoslp softclockmp 75782 42382 0 0 2 0x40014200 softclock 49363 47049 0 0 3 0x40014200 idle0 1 444285 0 0 3 0x80082 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{0}> show all locks Process 20274 (syz-executor) thread 0xffff80003c4627e8 (323226) exclusive rrwlock inode r = 0 (0xfffffd806bd697c8) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x42b sys/kern/kern_rwlock.c:319 #2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570 #5 vget+0x2bd sys/kern/vfs_subr.c:693 #6 ufs_ihashget+0x185 sys/ufs/ufs/ufs_ihash.c:98 #7 ffs_vget+0x8c sys/ufs/ffs/ffs_vfsops.c:1203 #8 ufs_lookup+0x19f8 sys/ufs/ufs/ufs_lookup.c:478 #9 VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85 #10 vfs_lookup+0x8fa sys/kern/vfs_lookup.c:566 #11 namei+0x7aa sys/kern/vfs_lookup.c:250 #12 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1864 #13 syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] #13 syscall+0xb08 sys/arch/amd64/amd64/trap.c:748 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806e19f238) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x42b sys/kern/kern_rwlock.c:319 #2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570 #5 vfs_lookup+0x109 sys/kern/vfs_lookup.c:418 #6 namei+0x7aa sys/kern/vfs_lookup.c:250 #7 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1864 #8 syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] #8 syscall+0xb08 sys/arch/amd64/amd64/trap.c:748 #9 Xsyscall+0x128 Process 49852 (softnet0) thread 0xffff8000ffffe000 (379262) shared rwlock softnet0 r = 0 (0xffff80000002c078) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1160 #1 taskq_thread+0x12a sys/kern/kern_task.c:442 #2 proc_trampoline+0x10 Process 96689 (systqmp) thread 0xffff8000ffffe7b0 (128841) shared rwlock systqmp r = 0 (0xffffffff838002e8) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1160 #1 taskq_thread+0x12a sys/kern/kern_task.c:442 #2 proc_trampoline+0x10 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10260 11160K 11657K 166960K 14095 0 pcb 17 16K 18K 166960K 627 0 rtable 239 11K 11K 166960K 525 0 pf 39 18K 82K 166960K 151 0 ifaddr 44 8K 8K 166960K 112 0 ifgroup 59 2K 2K 166960K 185 0 sysctl 4 1K 9K 166960K 18 0 counters 72 37K 38K 166960K 204 0 ioctlops 0 0K 4K 166960K 1714 0 iov 1 12K 16K 166960K 144 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1391 88K 88K 166960K 2842 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 10K 14K 166960K 22 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 44 0 dirhash 12 2K 2K 166960K 24 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 17 61K 240K 166960K 1533 0 sigio 0 0K 0K 166960K 41 0 proc 75 131K 180K 166960K 762 0 subproc 72 4K 4K 166960K 81 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 201 0 in_multi 94 6K 7K 166960K 176 0 ether_multi 1 0K 0K 166960K 24 0 mrt 1 0K 0K 166960K 9 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 283 1261K 1261K 166960K 283 0 exec 0 0K 1K 166960K 776 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 253 168K 182K 166960K 15698 0 UVM aobj 47 5K 5K 166960K 55 0 pinsyscall 44 88K 101K 166960K 2682 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 84 0 NDP 13 0K 2K 166960K 73 0 temp 78 8684K 8926K 166960K 64622 0 kqueue 14 22K 32K 166960K 292 0 SYN cache 2 16K 16K 166960K 2 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 120 193 0 189 3 2 1 3 0 8 0 rtentry 176 166 0 73 5 0 5 5 0 8 0 unpcb 144 1422 0 1403 14 12 2 6 0 8 0 syncache 336 13 0 13 4 3 1 1 0 8 1 tcpqe 32 3 0 3 2 2 0 1 0 8 0 tcpcb 736 546 0 537 19 17 2 7 0 8 1 arp 128 22 0 9 1 0 1 1 0 8 0 inpcb 328 1967 0 1953 23 13 10 12 0 8 8 nd6 144 23 0 2 1 0 1 1 0 8 0 pkpcb 40 74 0 74 3 2 1 1 0 8 1 kcovpl 48 9 0 1 1 0 1 1 0 8 0 mppekey 1024 1 0 1 1 1 0 1 0 8 0 ppxss 1192 51 0 50 2 1 1 1 0 8 0 pppxif 1504 8 0 7 2 1 1 1 0 8 0 pfstscr 40 1 0 0 1 0 1 1 0 8 0 pffrag 232 10 0 2 1 0 1 1 0 482 0 pffrnode 88 9 0 2 1 0 1 1 0 8 0 pffrent 40 17 0 8 1 0 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 pfrktable 1344 2 0 2 2 2 0 1 0 8 0 pfstitem 24 109 0 26 1 0 1 1 0 8 0 pfstkey 128 109 0 26 3 0 3 3 0 8 0 pfstate 384 109 0 26 9 0 9 9 0 8 0 pfrule 1344 22 0 16 2 0 2 2 0 8 0 rttmr 136 3 0 3 2 1 1 1 0 8 1 art_heap8 4096 4 0 0 4 0 4 4 0 8 0 art_heap4 256 742 0 331 35 5 30 30 0 8 1 art_table 40 746 0 331 5 0 5 5 0 8 0 art_node 32 165 0 85 1 0 1 1 0 8 0 sysvmsgpl 40 9 0 4 1 0 1 1 0 8 0 semupl 112 2 0 2 2 2 0 1 0 8 0 semapl 112 41 0 31 1 0 1 1 0 8 0 shmpl 112 52 0 8 2 0 2 2 0 8 0 dirhash 1024 25 0 8 3 0 3 3 0 8 0 dino2pl 256 4190 0 2683 95 0 95 95 0 8 0 ffsino 296 4190 0 2683 117 0 117 117 0 8 0 nchpl 144 6324 0 4625 64 0 64 64 0 8 0 rtmask 32 12 0 12 3 2 1 1 0 8 1 uvmvnodes 80 5226 0 0 107 0 107 107 0 8 0 vnodes 216 5226 0 0 291 0 291 291 0 8 0 namei 1024 23116 0 23116 4 3 1 1 0 8 1 percpumem 16 117 0 66 1 0 1 1 0 8 0 kstatmem 264 114 0 84 5 2 3 3 0 8 1 scsiplug 72 7 0 7 3 2 1 1 0 8 1 scxspl 216 29332 0 29332 15 14 1 8 1 8 1 plimitpl 152 372 0 352 1 0 1 1 0 8 0 sigapl 424 1848 0 1792 9 1 8 9 0 8 0 knotepl 120 596 0 0 18 0 18 18 0 8 0 kqueuepl 224 567 0 554 7 6 1 5 0 8 0 pipepl 344 266 0 238 6 3 3 6 0 8 0 fdescpl 528 1803 0 1771 3 0 3 3 0 8 0 filepl 160 13301 0 13065 28 12 16 18 0 8 3 lockfpl 104 948 0 946 1 0 1 1 0 8 0 lockfspl 48 408 0 406 1 0 1 1 0 8 0 sessionpl 144 32 0 22 1 0 1 1 0 8 0 pgrppl 48 58 0 40 1 0 1 1 0 8 0 ucredpl 104 1901 0 1885 1 0 1 1 0 8 0 zombiepl 144 2229 0 2225 3 2 1 1 0 8 0 processpl 1248 1848 0 1792 6 0 6 6 0 8 1 procpl 656 4302 0 4241 9 2 7 9 0 8 0 sosppl 168 27 0 27 3 2 1 1 0 8 1 sockpl 752 3686 0 3649 42 29 13 18 0 8 8 mcl64k 65536 5 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 110 0 0 14 0 14 14 0 8 0 mcl2k 2048 36 0 0 4 0 4 4 0 8 0 mtagpl 96 98 0 0 3 0 3 3 0 8 0 mbufpl 256 1237 0 0 77 0 77 77 0 8 0 bufpl 280 11476 0 5334 439 0 439 439 0 8 0 anonpl 32 11690 0 0 95 0 95 95 0 246 0 amapchunkpl 152 54534 0 54010 51 20 31 34 0 158 7 amappl16 200 5923 0 5882 52 34 18 26 0 8 8 amappl15 192 4 0 4 1 1 0 1 0 8 0 amappl14 184 131 0 118 1 0 1 1 0 8 0 amappl13 176 8 0 8 1 1 0 1 0 8 0 amappl12 168 2483 0 2451 3 1 2 2 0 8 0 amappl11 160 54 0 40 1 0 1 1 0 8 0 amappl10 152 6 0 6 1 1 0 1 0 8 0 amappl9 144 263 0 262 1 0 1 1 0 8 0 amappl8 136 25 0 22 1 0 1 1 0 8 0 amappl7 128 120 0 106 1 0 1 1 0 8 0 amappl6 120 197 0 192 1 0 1 1 0 8 0 amappl5 112 139 0 129 1 0 1 1 0 8 0 amappl4 104 336 0 315 1 0 1 1 0 8 0 amappl3 96 10778 0 10656 4 0 4 4 0 8 0 amappl2 88 717 0 649 2 0 2 2 0 8 0 amappl1 80 15179 0 14485 15 0 15 15 0 8 0 amappl 88 14697 0 14521 5 0 5 5 0 92 0 dma32768 32768 1 0 1 1 1 0 1 0 8 0 dma8192 8192 1 0 1 1 1 0 1 0 8 0 dma4096 4096 3 0 3 2 2 0 1 0 8 0 dma1024 1024 2 0 1 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 54 0 8 1 0 1 1 0 8 0 uaddrrnd 24 1803 0 1771 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1803 0 1771 1 0 1 1 0 8 0 vmmpekpl 168 16525 0 16482 4 1 3 3 0 8 0 vmmpepl 168 119179 0 117003 136 18 118 118 0 357 12 vmsppl 488 1802 0 1771 5 0 5 5 0 8 0 rwobjpl 80 37824 0 31489 131 0 131 131 0 8 1 pdppl 4096 3613 0 3542 109 36 73 81 0 8 2 pvpl 32 20729 0 0 169 2 167 167 0 265 0 pmappl 256 1802 0 1771 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 381 0 70 11 1 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 panic(ffffffff8346ab60) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff8341ad1e,ffffffff8341b694,3b7,ffffffff8341b717) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003b0274f0,ffffffff83366099) at refcnt_finalize+0x1db sys/kern/kern_synch.c:952 pppx_if_destroy(0,ffff80003b0274e8) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff80002a2a7c50) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003a8217b0) at spec_close+0x412 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806640e018,2,fffffd80097fb4e0,ffff80002a2a7c50) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156 vn_closefile(fffffd8068aa31e8,ffff80002a2a7c50) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8068aa31e8,ffff80002a2a7c50) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd8068aa31e8,ffff80002a2a7c50) at fdrop+0x126 sys/kern/kern_descrip.c:1267 closef(fffffd8068aa31e8,ffff80002a2a7c50) at closef+0x192 sys/kern/kern_descrip.c:1251 fdfree(ffff80002a2a7c50) at fdfree+0x116 sys/kern/kern_descrip.c:1182 exit1(ffff80002a2a7c50,0,0,1) at exit1+0x59c sys/kern/kern_exit.c:215 sys_exit(ffff80002a2a7c50,ffff80003a821b20,ffff80003a821a70) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003a821b20) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003a821b20) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7dadf8db1940, count: -16 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffff8000299ddff0) 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(ffffffff838e2b30) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff838e2b30) at __mp_lock+0x192 sys/kern/kern_lock.c:165 ktrstruct(ffff8000ffff2010,ffffffff83477b7f,ffff80002a2bf870,20) at ktrstruct+0xdf sys/kern/kern_ktrace.c:313 sys_kevent(ffff8000ffff2010,ffff80002a2bfb00,ffff80002a2bfa50) at sys_kevent+0x80f sys/kern/kern_event.c:1327 syscall(ffff80002a2bfb00) at syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2bfb00) at syscall+0xbc6 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7466d7887a70, count: 7 ddb{1}> trace x86_ipi_db(ffff8000299ddff0) 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(ffffffff838e2b30) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff838e2b30) at __mp_lock+0x192 sys/kern/kern_lock.c:165 ktrstruct(ffff8000ffff2010,ffffffff83477b7f,ffff80002a2bf870,20) at ktrstruct+0xdf sys/kern/kern_ktrace.c:313 sys_kevent(ffff8000ffff2010,ffff80002a2bfb00,ffff80002a2bfa50) at sys_kevent+0x80f sys/kern/kern_event.c:1327 syscall(ffff80002a2bfb00) at syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2bfb00) at syscall+0xbc6 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7466d7887a70, count: -8