panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 953 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 218941 44809 0 0x14000 0x200 0 reaper db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833716c8) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833afcda,ffffffff833bc0eb,3b9,ffffffff833e65d6) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c4734e8,ffffffff8336b7bf) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954 pppx_if_destroy(205b9a,ffff80003c4734e0) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,1,2000,ffff80003c463cb0) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003140f660) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd80641b3c00,1,fffffd80097fb618,ffff80003c463cb0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b843b80,ffff80003c463cb0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b843b80,ffff80003c463cb0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806b843b80,ffff80003c463cb0) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806b843b80,ffff80003c463cb0) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80003c463cb0) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80003c463cb0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c463cb0,ffff80003140f9d0,ffff80003140f920) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff80003140f9c0, 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{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic *cpu1: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 953 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833716c8) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833afcda,ffffffff833bc0eb,3b9,ffffffff833e65d6) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c4734e8,ffffffff8336b7bf) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954 pppx_if_destroy(205b9a,ffff80003c4734e0) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,1,2000,ffff80003c463cb0) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003140f660) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd80641b3c00,1,fffffd80097fb618,ffff80003c463cb0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b843b80,ffff80003c463cb0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b843b80,ffff80003c463cb0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806b843b80,ffff80003c463cb0) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806b843b80,ffff80003c463cb0) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80003c463cb0) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80003c463cb0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c463cb0,ffff80003140f9d0,ffff80003140f920) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003140f9d0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003140f9d0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:746 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7870f20f4bd0, count: -16 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff80003140f430 rbx 0xffff8000299feddf rdx 0 rcx 0xffff80003c463cb0 rax 0xffff8000299fdff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0x31b68819692effd5 r11 0xfcada4b4a8f0ee4 r12 0xffff8000299febe0 r13 0 r14 0 r15 0x1 rip 0xffffffff821fabb5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003140f420 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor) tid=245667 pid=72693 tcnt=0 stat=onproc flags process=1008 proc=2000 runpri=32, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0xffff80003c463cb0 scnt=-1 ecnt=1 forw=0xffffffffffffffff, list=0xffff80003c462558,0xffff80003c4634f8 process=0xffff8000398379e0 user=0xffff80003140a000, vmspace=0xfffffd800b0275b8 estcpu=36, cpticks=2, pctcpu=0.0, user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 48619 14598 18056 60929 2 0x10 syz-executor 48619 245216 18056 60929 3 0x4000010 smrbar syz-executor 80563 15723 33302 0 2 0 syz-executor 80563 253939 33302 0 3 0x4000080 fsleep syz-executor 14655 14390 52038 60929 3 0x3010 suspend syz-executor 14655 17848 52038 60929 3 0x4081010 biowait syz-executor 14655 198644 52038 60929 3 0x4081010 inode syz-executor 21987 136462 33323 0 2 0x2 syz-executor 34137 489999 94800 0 2 0 syz-executor 34137 150419 94800 0 3 0x4000080 sbwait syz-executor 34137 81479 94800 0 3 0x4000080 fsleep syz-executor 2091 496979 10570 0 2 0 syz-executor 2091 26482 10570 0 3 0x4000080 ttyin syz-executor 2091 494600 10570 0 3 0x4000080 fsleep syz-executor 2091 356624 10570 0 3 0x4000080 fsleep syz-executor 95044 260465 15114 -1 3 0x3010 suspend syz-executor 95044 10879 15114 -1 2 0x4081010 syz-executor 785 65053 0 0 3 0x14200 bored sosplice 52038 117478 33323 0 2 0x2 syz-executor 18056 166997 33323 0 3 0x82 nanoslp syz-executor 10570 22141 33323 0 2 0x2 syz-executor 15114 134107 33323 0 3 0x82 wait syz-executor 33302 441746 33323 0 3 0x82 nanoslp syz-executor 94800 348591 33323 0 3 0x82 nanoslp syz-executor 76259 191156 33323 0 3 0x82 nanoslp syz-executor 33323 501321 76717 0 2 0x2 syz-executor 76717 196640 82563 0 3 0x10008a sigsusp ksh 82563 332396 72675 0 3 0x98 kqread sshd-session 72675 114039 80236 0 3 0x92 kqread sshd-session 70586 426834 1 0 3 0x100083 ttyin getty 80236 373016 1 0 3 0x88 kqread sshd 27272 160359 68302 74 3 0x1100092 bpf pflogd 68302 501283 1 0 3 0x80 sbwait pflogd 27782 214855 96311 73 3 0x1100090 kqread syslogd 96311 74000 1 0 3 0x100082 sbwait syslogd 70227 390043 1 0 3 0x100080 kqread resolvd 52064 432983 86913 77 3 0x100092 kqread dhcpleased 71629 227363 86913 77 3 0x100092 kqread dhcpleased 86913 169585 1 0 3 0x80 kqread dhcpleased 19469 465467 0 0 3 0x14200 bored smr 95958 247659 0 0 2 0x14200 zerothread 10507 201644 0 0 3 0x14200 aiodoned aiodoned 17875 325771 0 0 3 0x14200 syncer update 97290 521053 0 0 3 0x14200 cleaner cleaner 44809 218941 0 0 7 0x14200 reaper 46371 501041 0 0 3 0x14200 pgdaemon pagedaemon 56891 43033 0 0 3 0x14200 bored viomb 22271 479628 0 0 3 0x40014200 acpi0 acpi0 66155 286754 0 0 3 0x40014200 idle1 79624 43326 0 0 3 0x14200 bored softnet7 20277 101241 0 0 3 0x14200 bored softnet6 59675 364205 0 0 3 0x14200 bored softnet5 34769 332604 0 0 3 0x14200 bored softnet4 45692 486458 0 0 3 0x14200 bored softnet3 48607 139191 0 0 3 0x14200 bored softnet2 6129 83893 0 0 3 0x14200 bored softnet1 56705 96924 0 0 3 0x14200 bored softnet0 93008 494514 0 0 3 0x14200 bored systqmp 48804 137479 0 0 3 0x14200 bored systq 26221 293004 0 0 3 0x14200 tmoslp softclockmp 96514 83881 0 0 3 0x40014200 tmoslp softclock 46667 311973 0 0 3 0x40014200 idle0 1 199844 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{1}> show all locks CPU 0: exclusive mutex &uvm.fpageqlock r = 0 (0xffffffff8387b620) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 mtx_enter_try+0x1ad sys/kern/kern_lock.c:311 #2 mtx_enter+0x62 sys/kern/kern_lock.c:261 #3 uvm_pmr_freepageq+0x15c sys/uvm/uvm_pmemrange.c:1371 #4 km_free+0x36b sys/uvm/uvm_km.c:827 #5 uvm_uarea_free+0x4f sys/uvm/uvm_glue.c:304 #6 reaper+0x1aa sys/kern/kern_exit.c:493 #7 proc_trampoline+0x10 Process 14655 (syz-executor) thread 0xffff80003c463a18 (17848) exclusive rrwlock inode r = 0 (0xfffffd806e0ac6e0) #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 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10226 11116K 11365K 166960K 11498 0 pcb 18 12K 12K 166960K 68 0 rtable 195 8K 8K 166960K 316 0 pf 40 18K 67485K 166960K 86 0 ifaddr 40 6K 7K 166960K 65 0 ifgroup 64 2K 2K 166960K 106 0 sysctl 2 1K 9K 166960K 7 0 counters 74 37K 37K 166960K 114 0 ioctlops 0 0K 4K 166960K 1597 0 iov 1 4K 24K 166960K 29 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1350 85K 85K 166960K 1532 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 4 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 14 0 dirhash 12 2K 2K 166960K 12 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 17 61K 151K 166960K 421 0 sigio 0 0K 0K 166960K 8 0 proc 72 115K 164K 166960K 559 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 104 0 in_multi 78 5K 7K 166960K 114 0 ether_multi 1 0K 0K 166960K 1 0 mrt 0 0K 0K 166960K 3 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 79 360K 360K 166960K 79 0 exec 0 0K 1K 166960K 390 0 fusefs mount 1 32K 32K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 246 155K 165K 166960K 5483 0 UVM aobj 76 4K 4K 166960K 78 0 pinsyscall 42 84K 105K 166960K 1494 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 24 0 NDP 14 0K 2K 166960K 43 0 temp 43 8644K 8724K 166960K 20766 0 kqueue 14 22K 29K 166960K 97 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 26 0 0 1 0 1 1 0 8 0 rtpcb 120 53 0 49 1 0 1 1 0 8 0 rtentry 176 103 0 23 5 0 5 5 0 8 0 unpcb 144 368 0 344 4 1 3 4 0 8 2 syncache 336 4 0 4 1 1 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpcb 736 167 0 162 7 3 4 7 0 8 3 arp 136 11 0 2 1 0 1 1 0 8 0 inpcb 328 389 0 380 7 3 4 7 0 8 3 nd6 144 18 0 4 1 0 1 1 0 8 0 kcovpl 48 9 0 1 1 0 1 1 0 8 0 mppekey 1024 1 0 1 1 0 1 1 0 8 1 ppxss 1192 14 0 13 1 0 1 1 0 8 0 pppxif 1504 4 0 3 1 0 1 1 0 8 0 pffrag 232 6 0 2 1 0 1 1 0 482 0 pffrnode 88 5 0 2 1 0 1 1 0 8 0 pffrent 40 43 0 39 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 1 0 1 1 1 0 1 0 8 0 pfstitem 24 31 0 1 1 0 1 1 0 8 0 pfstkey 128 33 0 3 1 0 1 1 0 8 0 pfstate 384 31 0 2 3 0 3 3 0 8 0 pfrule 1344 22 0 17 2 1 1 2 0 8 0 rttmr 136 1 0 1 1 1 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 493 0 101 28 1 27 28 0 8 1 art_table 40 494 0 101 5 0 5 5 0 8 0 art_node 32 103 0 31 1 0 1 1 0 8 0 sysvmsgpl 40 7 0 4 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 10 0 0 1 0 1 1 0 8 0 shmpl 112 75 0 2 3 0 3 3 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 2073 0 555 95 0 95 95 0 8 0 ffsino 296 2073 0 555 117 0 117 117 0 8 0 nchpl 144 2645 0 949 63 0 63 63 0 8 0 rtmask 32 2 0 2 1 1 0 1 0 8 0 uvmvnodes 80 2232 0 0 46 0 46 46 0 8 0 vnodes 216 2232 0 0 124 0 124 124 0 8 0 namei 1024 8324 0 8324 2 0 2 2 0 8 2 percpumem 16 72 0 20 1 0 1 1 0 8 0 kstatmem 264 58 0 26 3 0 3 3 0 8 0 scsiplug 72 2 0 2 1 0 1 1 0 8 1 scxspl 216 14207 0 14206 9 1 8 8 1 8 7 plimitpl 152 99 0 78 1 0 1 1 0 8 0 sigapl 424 708 0 654 7 0 7 7 0 8 0 knotepl 120 523 0 0 16 0 16 16 0 8 0 kqueuepl 224 132 0 121 2 0 2 2 0 8 1 pipepl 344 138 0 110 4 0 4 4 0 8 1 fdescpl 528 684 0 653 3 0 3 3 0 8 0 filepl 160 3381 0 3148 13 2 11 13 0 8 0 lockfpl 104 120 0 116 1 0 1 1 0 8 0 lockfspl 48 52 0 48 1 0 1 1 0 8 0 sessionpl 144 24 0 15 1 0 1 1 0 8 0 pgrppl 48 39 0 22 1 0 1 1 0 8 0 ucredpl 104 322 0 306 1 0 1 1 0 8 0 zombiepl 144 657 0 654 1 0 1 1 0 8 0 processpl 1232 708 0 654 5 0 5 5 0 8 0 procpl 664 1195 0 1131 7 0 7 7 0 8 0 sockpl 752 817 0 780 11 3 8 11 0 8 3 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 128 0 0 16 0 16 16 0 8 0 mcl2k 2048 27 0 0 4 0 4 4 0 8 0 mtagpl 96 4 0 0 1 0 1 1 0 8 0 mbufpl 256 142 0 0 9 0 9 9 0 8 0 bufpl 280 7035 0 891 439 0 439 439 0 8 0 anonpl 32 10454 0 0 85 0 85 85 0 246 0 amapchunkpl 152 17736 0 17228 35 3 32 32 0 158 10 amappl16 200 3225 0 3179 20 7 13 17 0 8 8 amappl15 192 4 0 4 1 1 0 1 0 8 0 amappl14 184 116 0 104 1 0 1 1 0 8 0 amappl13 176 26 0 26 1 1 0 1 0 8 0 amappl12 168 1329 0 1298 3 1 2 2 0 8 0 amappl11 160 80 0 66 1 0 1 1 0 8 0 amappl10 152 14 0 12 1 0 1 1 0 8 0 amappl9 144 251 0 251 1 1 0 1 0 8 0 amappl8 136 27 0 25 1 0 1 1 0 8 0 amappl7 128 124 0 111 1 0 1 1 0 8 0 amappl6 120 175 0 171 1 0 1 1 0 8 0 amappl5 112 135 0 125 1 0 1 1 0 8 0 amappl4 104 313 0 293 1 0 1 1 0 8 0 amappl3 96 2809 0 2711 4 1 3 3 0 8 0 amappl2 88 923 0 846 2 0 2 2 0 8 0 amappl1 80 9365 0 8758 15 1 14 15 0 8 0 amappl 88 4753 0 4578 5 0 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 77 0 2 2 0 2 2 0 8 0 uaddrrnd 24 684 0 653 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 684 0 653 1 0 1 1 0 8 0 vmmpekpl 168 7234 0 7198 3 0 3 3 0 8 0 vmmpepl 168 50318 0 48309 102 0 102 102 0 357 8 vmsppl 488 683 0 653 5 1 4 5 0 8 0 rwobjpl 80 19042 0 15774 68 0 68 68 0 8 0 pdppl 4096 1375 0 1306 95 24 71 83 0 8 2 pvpl 32 18044 0 0 146 0 146 146 0 265 0 pmappl 256 683 0 653 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 271 0 31 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff83823ff0) 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 mtx_enter(ffffffff8377dfa0) at mtx_enter+0x176 sys/kern/kern_lock.c:277 msleep_nsec(ffffffff8377dfd8,ffffffff8377dfa0,4,ffffffff8338118d,ffffffffffffffff) at msleep_nsec+0x2d3 sys/kern/kern_synch.c:209 reaper(ffff8000ffffc008) at reaper+0x13b sys/kern/kern_exit.c:477 end trace frame: 0x0, count: 9 ddb{0}> trace x86_ipi_db(ffffffff83823ff0) 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 mtx_enter(ffffffff8377dfa0) at mtx_enter+0x176 sys/kern/kern_lock.c:277 msleep_nsec(ffffffff8377dfd8,ffffffff8377dfa0,4,ffffffff8338118d,ffffffffffffffff) at msleep_nsec+0x2d3 sys/kern/kern_synch.c:209 reaper(ffff8000ffffc008) at reaper+0x13b sys/kern/kern_exit.c:477 end trace frame: 0x0, count: -6 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x25: addq $0x8,%rsp db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833716c8) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833afcda,ffffffff833bc0eb,3b9,ffffffff833e65d6) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c4734e8,ffffffff8336b7bf) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954 pppx_if_destroy(205b9a,ffff80003c4734e0) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,1,2000,ffff80003c463cb0) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003140f660) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd80641b3c00,1,fffffd80097fb618,ffff80003c463cb0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b843b80,ffff80003c463cb0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b843b80,ffff80003c463cb0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806b843b80,ffff80003c463cb0) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806b843b80,ffff80003c463cb0) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80003c463cb0) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80003c463cb0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c463cb0,ffff80003140f9d0,ffff80003140f920) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff80003140f9c0, count: 0 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833716c8) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833afcda,ffffffff833bc0eb,3b9,ffffffff833e65d6) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c4734e8,ffffffff8336b7bf) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954 pppx_if_destroy(205b9a,ffff80003c4734e0) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,1,2000,ffff80003c463cb0) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003140f660) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd80641b3c00,1,fffffd80097fb618,ffff80003c463cb0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b843b80,ffff80003c463cb0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b843b80,ffff80003c463cb0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806b843b80,ffff80003c463cb0) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806b843b80,ffff80003c463cb0) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80003c463cb0) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80003c463cb0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c463cb0,ffff80003140f9d0,ffff80003140f920) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003140f9d0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003140f9d0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:746 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7870f20f4bd0, count: -16