panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 955 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 125186 31070 0 0 0 0 syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83443627) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff83486700,ffffffff83495f38,3bb,ffffffff834bef63) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c3eaf10,ffffffff8343be52) at refcnt_finalize+0x1db sys/kern/kern_synch.c:956 pppx_if_destroy(205b9a,ffff80003c3eaf08) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff8000fffee018) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff800038fd0e10) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8069ddf1b8,2,fffffd80097fd478,ffff8000fffee018) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd805ea80b40,ffff8000fffee018) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd805ea80b40,ffff8000fffee018) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd805ea80b40,ffff8000fffee018) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd805ea80b40,ffff8000fffee018) at closef+0x192 sys/kern/kern_descrip.c:1265 fdfree(ffff8000fffee018) at fdfree+0x116 sys/kern/kern_descrip.c:1196 exit1(ffff8000fffee018,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000fffee018,ffff800038fd1180,ffff800038fd10d0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff800038fd1170, 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 955 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83443627) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff83486700,ffffffff83495f38,3bb,ffffffff834bef63) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c3eaf10,ffffffff8343be52) at refcnt_finalize+0x1db sys/kern/kern_synch.c:956 pppx_if_destroy(205b9a,ffff80003c3eaf08) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff8000fffee018) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff800038fd0e10) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8069ddf1b8,2,fffffd80097fd478,ffff8000fffee018) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd805ea80b40,ffff8000fffee018) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd805ea80b40,ffff8000fffee018) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd805ea80b40,ffff8000fffee018) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd805ea80b40,ffff8000fffee018) at closef+0x192 sys/kern/kern_descrip.c:1265 fdfree(ffff8000fffee018) at fdfree+0x116 sys/kern/kern_descrip.c:1196 exit1(ffff8000fffee018,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000fffee018,ffff800038fd1180,ffff800038fd10d0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff800038fd1180) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800038fd1180) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x798e6fa08e80, count: -16 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800038fd0be0 rbx 0xffff8000299bee07 rdx 0 rcx 0xffff8000fffee018 rax 0xffff8000299bdff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xf11342d3d1de16f8 r11 0xf00a2f9cd26dfa72 r12 0xffff8000299bec08 r13 0 r14 0 r15 0x1 rip 0xffffffff81087295 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff800038fd0bd0 ss 0 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor) tid=54257 pid=90647 tcnt=0 stat=onproc flags process=1008 proc=2000 runpri=0, usrpri=79, slppri=0, nice=20 wchan=0x0, wmesg=, ps_single=0xffff8000fffee018 scnt=-1 ecnt=1 forw=0xffffffffffffffff, list=0xffff800038fd94e0,0xffff80003c3f2568 process=0xffff80002a39dcf8 user=0xffff800038fcc000, vmspace=0xfffffd800e8793f0 estcpu=29, cpticks=16, pctcpu=0.13, user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 31070 125186 89795 0 7 0 syz-executor 23321 329703 73550 0 2 0 syz-executor 50859 35934 42593 0 2 0 syz-executor 50859 202127 42593 0 3 0x4000080 fifor syz-executor 50859 17186 42593 0 2 0x4000000 syz-executor 30102 308073 75282 0 2 0 syz-executor 30102 329284 75282 0 3 0x4000080 fsleep syz-executor 62577 411377 9518 0 2 0 syz-executor 62577 2198 9518 0 3 0x4000000 smrbar syz-executor 47911 309897 0 0 3 0x14200 acct acct 38304 52226 1 0 3 0x100083 ttyin getty 88335 266558 73113 0 3 0x82 nanoslp syz-executor 73550 40989 73113 0 3 0x82 nanoslp syz-executor 89795 239377 73113 0 3 0x82 nanoslp syz-executor 9518 285030 73113 0 3 0x82 nanoslp syz-executor 91386 92373 73113 0 3 0x82 nanoslp syz-executor 42593 337039 73113 0 3 0x82 nanoslp syz-executor 6248 284292 73113 0 3 0x82 nanoslp syz-executor 75282 457776 73113 0 3 0x82 nanoslp syz-executor 73113 89916 4414 0 3 0x82 kqread syz-executor 4414 407883 47774 0 3 0x10008a sigsusp ksh 47774 331274 86957 0 3 0x98 kqread sshd-session 86957 338534 94975 0 3 0x92 kqread sshd-session 94975 207897 1 0 3 0x88 kqread sshd 89528 273458 52610 74 3 0x1100092 bpf pflogd 52610 485263 1 0 3 0x80 sbwait pflogd 53393 173618 23290 73 3 0x1100090 kqread syslogd 23290 515320 1 0 3 0x100082 sbwait syslogd 68455 496241 1 0 3 0x100080 kqread resolvd 40355 520958 82449 77 3 0x100092 kqread dhcpleased 83583 331996 82449 77 3 0x100092 kqread dhcpleased 82449 102125 1 0 3 0x80 kqread dhcpleased 37021 6527 0 0 2 0x40014200 smr 47367 142076 0 0 2 0x14200 zerothread 25159 495138 0 0 3 0x14200 aiodoned aiodoned 96156 84082 0 0 3 0x14200 syncer update 13826 287014 0 0 3 0x14200 cleaner cleaner 90692 102407 0 0 3 0x14200 reaper reaper 92865 212943 0 0 3 0x14200 pgdaemon pagedaemon 6336 174346 0 0 3 0x14200 bored viomb 32007 345394 0 0 3 0x40014200 acpi0 acpi0 12775 494031 0 0 3 0x40014200 idle1 29828 513690 0 0 3 0x14200 bored softnet1 64548 267721 0 0 3 0x14200 bored softnet0 77856 517677 0 0 3 0x14200 bored systqmp 33335 428926 0 0 3 0x14200 bored systq 88169 91429 0 0 3 0x14200 tmoslp softclockmp 75264 47157 0 0 3 0x40014200 tmoslp softclock 2929 220776 0 0 3 0x40014200 idle0 1 94827 0 0 3 0x80082 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{1}> show all locks Process 31070 (syz-executor) thread 0xffff8000fffef770 (125186) ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11123 12302K 12448K 166960K 13161 0 pcb 17 16K 18K 166960K 215 0 rtable 225 9K 9K 166960K 432 0 pf 43 19K 82K 166960K 108 0 ifaddr 45 7K 8K 166960K 87 0 ifgroup 66 2K 2K 166960K 135 0 sysctl 3 1K 9K 166960K 15 0 counters 78 37K 38K 166960K 154 0 ioctlops 0 0K 4K 166960K 1579 0 iov 0 0K 16K 166960K 99 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1419 89K 90K 166960K 2111 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 14 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 27 0 dirhash 12 2K 2K 166960K 27 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 102K 166960K 712 0 sigio 0 0K 0K 166960K 15 0 proc 73 115K 180K 166960K 636 0 subproc 72 4K 4K 166960K 72 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 148 0 in_multi 92 6K 7K 166960K 152 0 ether_multi 1 0K 0K 166960K 13 0 mrt 1 0K 0K 166960K 26 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 229 1023K 1023K 166960K 229 0 exec 0 0K 1K 166960K 579 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 229 159K 177K 166960K 8366 0 UVM aobj 39 2K 2K 166960K 39 0 pinsyscall 43 86K 110K 166960K 1880 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 56 0 NDP 15 0K 2K 166960K 55 0 temp 56 9079K 9143K 166960K 20384 0 kqueue 13 20K 32K 166960K 146 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 81 0 78 1 0 1 1 0 8 0 rtentry 176 129 0 35 6 0 6 6 0 8 0 unpcb 144 463 0 444 4 2 2 4 0 8 1 syncache 336 6 0 6 2 1 1 1 0 8 1 tcpcb 736 340 0 336 13 8 5 7 0 8 4 arp 136 19 0 2 1 0 1 1 0 8 0 inpcb 328 1040 0 1031 18 11 7 12 0 8 6 nd6 152 26 0 3 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 0 1 1 0 8 1 kcovpl 48 8 0 0 1 0 1 1 0 8 0 mppekey 1024 2 0 2 1 0 1 1 0 8 1 ppxss 1192 31 0 29 2 1 1 1 0 8 0 pppxif 1504 7 0 6 2 1 1 1 0 8 0 pfstscr 40 2 0 2 1 1 0 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 8 0 4 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 pfstitem 24 57 0 14 1 0 1 1 0 8 0 pfstkey 128 58 0 15 2 0 2 2 0 8 0 pfstate 448 58 0 15 6 0 6 6 0 8 0 pfrule 1360 25 0 20 2 1 1 2 0 8 0 rttmr 136 1 0 1 1 0 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 592 0 170 30 2 28 29 0 8 0 art_table 40 593 0 170 5 0 5 5 0 8 0 art_node 32 128 0 45 1 0 1 1 0 8 0 sysvmsgpl 40 11 0 7 1 0 1 1 0 8 0 semapl 112 23 0 13 1 0 1 1 0 8 0 shmpl 112 36 0 0 2 0 2 2 0 8 0 dirhash 1024 27 0 10 3 0 3 3 0 8 0 dino2pl 256 2781 0 1320 93 0 93 93 0 8 0 ffsino 296 2781 0 1320 114 0 114 114 0 8 0 nchpl 144 3743 0 2039 64 0 64 64 0 8 0 rtmask 32 4 0 4 1 1 0 1 0 8 0 vnodes 216 3326 0 0 185 0 185 185 0 8 0 namei 1024 12672 0 12672 3 2 1 2 0 8 1 percpumem 16 92 0 38 1 0 1 1 0 8 0 kstatmem 264 80 0 46 4 1 3 3 0 8 0 acpiwqpl 32 1 0 1 1 0 1 1 1 8 1 scsiplug 72 5 0 5 2 1 1 1 0 8 1 scxspl 216 18994 0 18994 12 10 2 8 1 8 2 plimitpl 152 367 0 349 1 0 1 1 0 8 0 sigapl 424 1028 0 979 7 1 6 7 0 8 0 knotepl 120 527 0 0 16 0 16 16 0 8 0 kqueuepl 224 354 0 343 2 0 2 2 0 8 1 pipepl 344 176 0 149 3 0 3 3 0 8 0 fdescpl 528 1009 0 977 3 0 3 3 0 8 0 filepl 160 6192 0 5968 20 6 14 16 0 8 3 lockfpl 104 373 0 371 1 0 1 1 0 8 0 lockfspl 48 138 0 136 1 0 1 1 0 8 0 sessionpl 144 27 0 18 1 0 1 1 0 8 0 pgrppl 48 38 0 21 1 0 1 1 0 8 0 ucredpl 104 905 0 890 1 0 1 1 0 8 0 zombiepl 144 982 0 979 1 0 1 1 0 8 0 processpl 1232 1028 0 979 5 1 4 5 0 8 0 procpl 664 2058 0 2005 6 0 6 6 0 8 0 sosppl 176 3 0 3 2 1 1 1 0 8 1 sockpl 752 1596 0 1565 28 17 11 17 0 8 7 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 117 0 0 15 0 15 15 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 39 0 0 5 0 5 5 0 8 0 mtagpl 96 5 0 0 1 0 1 1 0 8 0 mbufpl 256 226 0 0 15 0 15 15 0 8 0 bufpl 280 6864 0 734 438 0 438 438 0 8 0 anonpl 32 10006 0 0 81 0 81 81 0 246 0 amapchunkpl 152 26979 0 26511 31 7 24 31 0 158 4 amappl16 200 3850 0 3818 27 14 13 18 0 8 8 amappl15 192 7 0 6 1 0 1 1 0 8 0 amappl14 184 430 0 429 1 0 1 1 0 8 0 amappl13 176 128 0 116 1 0 1 1 0 8 0 amappl12 168 1259 0 1230 2 0 2 2 0 8 0 amappl11 160 11 0 11 1 1 0 1 0 8 0 amappl10 152 65 0 50 1 0 1 1 0 8 0 amappl9 144 263 0 263 1 1 0 1 0 8 0 amappl8 136 97 0 95 1 0 1 1 0 8 0 amappl7 128 152 0 139 1 0 1 1 0 8 0 amappl6 120 166 0 164 1 0 1 1 0 8 0 amappl5 112 109 0 98 1 0 1 1 0 8 0 amappl4 104 312 0 294 1 0 1 1 0 8 0 amappl3 96 5355 0 5246 4 0 4 4 0 8 0 amappl2 88 573 0 513 2 0 2 2 0 8 0 amappl1 80 13108 0 12505 16 0 16 16 0 8 1 amappl 88 7514 0 7356 5 0 5 5 0 92 0 uvmvnodes 80 122 0 0 3 0 3 3 0 8 0 dma32768 32768 1 0 1 1 0 1 1 0 8 1 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 38 0 0 1 0 1 1 0 8 0 uaddrrnd 24 1009 0 977 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1009 0 977 1 0 1 1 0 8 0 vmmpekpl 168 10395 0 10358 2 0 2 2 0 8 0 vmmpepl 168 73086 0 71142 108 8 100 100 0 357 11 vmsppl 488 1008 0 977 5 0 5 5 0 8 1 rwobjpl 80 23126 0 22039 30 2 28 29 0 8 2 pdppl 4096 2025 0 1954 111 38 73 87 0 8 2 pvpl 32 18650 0 0 153 2 151 151 0 265 0 pmappl 256 1008 0 977 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 309 0 54 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff8388aff0) 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(ffffffff8396a900) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff8396a900) at __mp_lock+0x192 sys/kern/kern_lock.c:173 softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 __mp_lock(ffffffff8396a900) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff8396a900) at __mp_lock+0x192 sys/kern/kern_lock.c:173 sys_mmap(ffff8000fffef770,ffff800034bb1080,ffff800034bb0fd0) at sys_mmap+0x63b sys/uvm/uvm_mmap.c:292 syscall(ffff800034bb1080) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800034bb1080) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7c1525395230, count: 4 ddb{0}> trace x86_ipi_db(ffffffff8388aff0) 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(ffffffff8396a900) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff8396a900) at __mp_lock+0x192 sys/kern/kern_lock.c:173 softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 __mp_lock(ffffffff8396a900) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff8396a900) at __mp_lock+0x192 sys/kern/kern_lock.c:173 sys_mmap(ffff8000fffef770,ffff800034bb1080,ffff800034bb0fd0) at sys_mmap+0x63b sys/uvm/uvm_mmap.c:292 syscall(ffff800034bb1080) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800034bb1080) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7c1525395230, count: -11 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(ffffffff83443627) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff83486700,ffffffff83495f38,3bb,ffffffff834bef63) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c3eaf10,ffffffff8343be52) at refcnt_finalize+0x1db sys/kern/kern_synch.c:956 pppx_if_destroy(205b9a,ffff80003c3eaf08) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff8000fffee018) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff800038fd0e10) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8069ddf1b8,2,fffffd80097fd478,ffff8000fffee018) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd805ea80b40,ffff8000fffee018) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd805ea80b40,ffff8000fffee018) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd805ea80b40,ffff8000fffee018) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd805ea80b40,ffff8000fffee018) at closef+0x192 sys/kern/kern_descrip.c:1265 fdfree(ffff8000fffee018) at fdfree+0x116 sys/kern/kern_descrip.c:1196 exit1(ffff8000fffee018,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000fffee018,ffff800038fd1180,ffff800038fd10d0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff800038fd1170, count: 0 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83443627) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff83486700,ffffffff83495f38,3bb,ffffffff834bef63) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c3eaf10,ffffffff8343be52) at refcnt_finalize+0x1db sys/kern/kern_synch.c:956 pppx_if_destroy(205b9a,ffff80003c3eaf08) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff8000fffee018) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff800038fd0e10) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8069ddf1b8,2,fffffd80097fd478,ffff8000fffee018) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd805ea80b40,ffff8000fffee018) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd805ea80b40,ffff8000fffee018) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd805ea80b40,ffff8000fffee018) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd805ea80b40,ffff8000fffee018) at closef+0x192 sys/kern/kern_descrip.c:1265 fdfree(ffff8000fffee018) at fdfree+0x116 sys/kern/kern_descrip.c:1196 exit1(ffff8000fffee018,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000fffee018,ffff800038fd1180,ffff800038fd10d0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff800038fd1180) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800038fd1180) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x798e6fa08e80, count: -16