panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_synch.c", line 955 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83484057) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff834c280d,ffffffff8352255f,3bb,ffffffff834fbd23) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c8ea6c0,ffffffff8347e20c) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:956 pppx_if_destroy(0,ffff80003c8ea6b8) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b92,1,2000,ffff80003c8f2a90) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003c900dd0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8063df3530,1,fffffd8007ffd618,ffff80003c8f2a90) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b967bd0,ffff80003c8f2a90) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffffd806b967bd0,ffff80003c8f2a90) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621 fdrop(fffffd806b967bd0,ffff80003c8f2a90) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd806b967bd0,ffff80003c8f2a90) at closef+0x190 sys/kern/kern_descrip.c:1265 fdfree(ffff80003c8f2a90) at fdfree+0x115 sys/kern/kern_descrip.c:1196 exit1(ffff80003c8f2a90,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c8f2a90,ffff80003c901130,ffff80003c901080) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff80003c901120, 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> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic *cpu0: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_synch.c", line 955 ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83484057) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff834c280d,ffffffff8352255f,3bb,ffffffff834fbd23) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c8ea6c0,ffffffff8347e20c) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:956 pppx_if_destroy(0,ffff80003c8ea6b8) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b92,1,2000,ffff80003c8f2a90) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003c900dd0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8063df3530,1,fffffd8007ffd618,ffff80003c8f2a90) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b967bd0,ffff80003c8f2a90) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffffd806b967bd0,ffff80003c8f2a90) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621 fdrop(fffffd806b967bd0,ffff80003c8f2a90) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd806b967bd0,ffff80003c8f2a90) at closef+0x190 sys/kern/kern_descrip.c:1265 fdfree(ffff80003c8f2a90) at fdfree+0x115 sys/kern/kern_descrip.c:1196 exit1(ffff80003c8f2a90,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c8f2a90,ffff80003c901130,ffff80003c901080) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003c901130) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80003c901130) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x781eb0ee5ff0, count: -16 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80003c900bb0 rbx 0 rdx 0 rcx 0 rax 0xffff80003c8f2a90 r8 0x101010101010101 r9 0x8080808080808080 r10 0xc685abbe599313aa r11 0xf13cca8c44d6b7ee r12 0 r13 0 r14 0 r15 0x1 rip 0xffffffff8304ee05 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003c900ba0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (syz-executor) tid=123572 pid=25426 tcnt=0 stat=onproc flags process=1008 proc=2000 runpri=32, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0xffff80003c8f2a90 scnt=-1 ecnt=1 forw=0xffffffffffffffff, list=0xffff80003c8f2fc0,0xffff80003c8fb258 process=0xffff8000ffff6d20 user=0xffff80003c8fc000, vmspace=0xfffffd800e1502f8 estcpu=36, cpticks=2, pctcpu=0.0, user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 71018 111174 48161 0 2 0 syz-executor 65439 148582 20977 0 2 0 syz-executor 65439 286805 20977 0 3 0x4000080 fsleep syz-executor 70583 48647 39111 0 3 0x80 nanoslp syz-executor 70583 264281 39111 0 2 0x4000000 syz-executor 70583 434306 39111 0 3 0x4000080 fsleep syz-executor 94076 268667 0 0 3 0x14200 acct acct 14966 292741 19512 0 3 0x80 nanoslp syz-executor 14966 233274 19512 0 3 0x4000080 netcon syz-executor 84722 458165 5460 0 3 0x1000080 nanoslp syz-executor 84722 479073 5460 0 3 0x5000080 sbwait syz-executor 38133 202617 0 0 3 0x14280 nfsidl nfsio 4129 178643 0 0 3 0x14280 nfsidl nfsio 23440 80159 0 0 3 0x14280 nfsidl nfsio 77878 396909 0 0 3 0x14280 nfsidl nfsio 98450 418348 0 0 3 0x14280 nfsidl nfsio 55137 180514 0 0 3 0x14280 nfsidl nfsio 97296 394617 0 0 3 0x14280 nfsidl nfsio 59404 467079 0 0 3 0x14280 nfsidl nfsio 40077 79240 0 0 3 0x14280 nfsidl nfsio 11103 378012 0 0 3 0x14280 nfsidl nfsio 11446 498187 0 0 3 0x14280 nfsidl nfsio 36599 171753 0 0 3 0x14280 nfsidl nfsio 21436 119580 0 0 3 0x14280 nfsidl nfsio 94005 478379 0 0 3 0x14280 nfsidl nfsio 64109 163820 0 0 3 0x14280 nfsidl nfsio 89506 56237 0 0 3 0x14280 nfsidl nfsio 21381 155782 0 0 3 0x14280 nfsidl nfsio 17243 1543 0 0 3 0x14280 nfsidl nfsio 43251 407270 0 0 3 0x14280 nfsidl nfsio 13504 506970 0 0 3 0x14280 nfsidl nfsio 39111 441330 14131 0 2 0xc82 syz-executor 34688 126446 14131 0 3 0x82 nanoslp syz-executor 48161 400768 14131 0 2 0xc82 syz-executor 20977 433439 14131 0 2 0xc82 syz-executor 19512 325819 14131 0 3 0x82 nanoslp syz-executor 5460 132466 14131 0 3 0x82 nanoslp syz-executor 91724 64869 14131 0 2 0x2 syz-executor 95574 436654 14131 0 2 0x2 syz-executor 14131 255545 28703 0 2 0x2 syz-executor 28703 336016 81170 0 3 0x10008a sigsusp ksh 81170 123123 40753 0 3 0x98 kqread sshd-session 40753 62134 18621 0 3 0x92 kqread sshd-session 6914 220256 1 0 3 0x100083 ttyin getty 18621 18223 1 0 3 0x88 kqread sshd 17416 457578 13977 73 3 0x1100090 kqread syslogd 13977 410589 1 0 3 0x100082 sbwait syslogd 26526 68030 1 0 3 0x100080 kqread resolvd 10147 413969 8773 77 2 0x100012 dhcpleased 78092 56120 8773 77 3 0x100092 kqread dhcpleased 8773 65588 1 0 3 0x80 kqread dhcpleased 78165 433852 0 0 3 0x14200 bored smr 41915 380038 0 0 2 0x14200 zerothread 98263 83241 0 0 3 0x14200 aiodoned aiodoned 40061 164984 0 0 3 0x14200 syncer update 10248 336609 0 0 3 0x14200 cleaner cleaner 6776 395332 0 0 3 0x14200 reaper reaper 27230 63359 0 0 3 0x14200 pgdaemon pagedaemon 53270 90683 0 0 3 0x14200 bored viomb 64611 102885 0 0 3 0x40014200 acpi0 acpi0 88831 476364 0 0 2 0x14200 softnet0 90589 21211 0 0 3 0x14200 smrbar systqmp 26490 84333 0 0 3 0x14200 bored systq 14777 469218 0 0 3 0x40014200 tmoslp softclock 61928 455087 0 0 3 0x40014200 idle0 1 519477 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11037 12100K 12370K 166960K 12310 0 pcb 17 12K 12K 166960K 57 0 rtable 241 7K 7K 166960K 375 0 pf 32 13K 72K 166960K 78 0 ifaddr 42 7K 8K 166960K 58 0 ifgroup 50 2K 2K 166960K 78 0 sysctl 1 1K 9K 166960K 5 0 counters 34 17K 18K 166960K 50 0 ioctlops 0 0K 4K 166960K 67 0 iov 0 0K 4K 166960K 7 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1295 81K 82K 166960K 1487 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 6 0 VM map 2 1K 1K 166960K 2 0 sem 7 0K 0K 166960K 7 0 dirhash 12 2K 2K 166960K 15 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 16 57K 97K 166960K 269 0 sigio 0 0K 0K 166960K 2 0 proc 60 59K 91K 166960K 512 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 1 0K 0K 166960K 11 0 in_multi 99 7K 7K 166960K 103 0 ether_multi 1 0K 0K 166960K 1 0 mrt 0 0K 0K 166960K 8 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 61 281K 281K 166960K 61 0 exec 0 0K 1K 166960K 386 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 2 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 209 158K 168K 166960K 4087 0 UVM aobj 9 2K 2K 166960K 11 0 pinsyscall 37 74K 94K 166960K 1379 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 13 0 NDP 11 0K 2K 166960K 37 0 temp 37 9106K 9123K 166960K 4028 0 kqueue 13 20K 29K 166960K 65 0 SYN cache 2 16K 16K 166960K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 39 0 36 1 0 1 1 0 8 0 rtentry 136 119 0 8 4 0 4 4 0 8 0 unpcb 144 90 0 73 1 0 1 1 0 8 0 syncache 336 4 0 4 1 1 0 1 0 8 0 tcpcb 736 45 0 37 1 0 1 1 0 8 0 arp 96 19 0 1 1 0 1 1 0 8 0 inpcb 328 172 0 160 3 1 2 2 0 8 0 nd6 112 25 0 0 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 ppxss 1072 14 0 13 2 1 1 1 0 8 0 pppxif 1416 4 0 3 1 0 1 1 0 8 0 pfstscr 40 6 0 2 1 0 1 1 0 8 0 pfanchor 1288 3 0 0 1 0 1 1 0 8 0 pfstitem 24 4 0 0 1 0 1 1 0 8 0 pfstkey 128 6 0 2 1 0 1 1 0 8 0 pfstate 384 3 0 1 1 0 1 1 0 8 0 pfrule 1360 3 0 2 1 0 1 1 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 256 504 0 45 31 0 31 31 0 8 2 art_table 40 505 0 45 5 0 5 5 0 8 0 art_node 32 119 0 18 1 0 1 1 0 8 0 sysvmsgpl 40 2 0 2 1 1 0 1 0 8 0 semapl 72 5 0 0 1 0 1 1 0 8 0 shmpl 112 8 0 2 1 0 1 1 0 8 0 dirhash 1024 19 0 2 3 0 3 3 0 8 0 dino2pl 256 1843 0 383 92 0 92 92 0 8 0 ffsino 256 1843 0 383 92 0 92 92 0 8 0 nchpl 144 2281 0 584 64 0 64 64 0 8 0 vnodes 216 1981 0 0 111 0 111 111 0 8 0 namei 1024 6853 0 6853 3 2 1 2 0 8 1 kstatmem 264 43 0 20 2 0 2 2 0 8 0 scsiplug 72 2 0 2 2 1 1 1 0 8 1 scxspl 216 7607 0 7607 10 2 8 8 1 8 8 plimitpl 152 46 0 30 1 0 1 1 0 8 0 sigapl 424 588 0 526 8 0 8 8 0 8 0 knotepl 120 9154 0 9107 29 13 16 16 0 8 13 kqueuepl 184 71 0 61 1 0 1 1 0 8 0 pipepl 304 134 0 106 3 0 3 3 0 8 0 fdescpl 448 554 0 526 5 1 4 5 0 8 0 filepl 120 2227 0 2010 10 0 10 10 0 8 2 lockfpl 104 47 0 42 1 0 1 1 0 8 0 lockfspl 48 24 0 19 1 0 1 1 0 8 0 sessionpl 144 25 0 17 1 0 1 1 0 8 0 pgrppl 48 34 0 18 1 0 1 1 0 8 0 ucredpl 104 239 0 228 1 0 1 1 0 8 0 zombiepl 144 527 0 526 1 0 1 1 0 8 0 processpl 1152 588 0 526 5 0 5 5 0 8 0 procpl 664 785 0 718 7 0 7 7 0 8 0 sosppl 176 3 0 3 1 0 1 1 0 8 1 sockpl 552 306 0 274 3 0 3 3 0 8 0 mcl64k 65536 10 0 10 1 0 1 1 0 8 1 mcl16k 16384 2 0 2 1 0 1 1 0 8 1 mcl8k 8192 5 0 5 2 1 1 1 0 8 1 mcl4k 4096 2665 0 2611 15 7 8 15 0 8 0 mcl2k 2048 236 0 234 1 0 1 1 0 8 0 mtagpl 96 5 0 4 2 1 1 1 0 8 0 mbufpl 256 5492 0 5323 13 1 12 12 0 8 0 bufpl 280 2457 0 103 169 0 169 169 0 8 0 anonpl 24 92732 0 89727 46 23 23 46 0 186 0 amapchunkpl 152 11525 0 11102 26 5 21 25 0 158 2 amappl16 200 1410 0 1383 16 13 3 15 0 8 0 amappl15 192 2 0 2 1 1 0 1 0 8 0 amappl14 184 411 0 410 1 0 1 1 0 8 0 amappl13 176 115 0 105 1 0 1 1 0 8 0 amappl12 168 792 0 766 2 0 2 2 0 8 0 amappl11 160 1 0 1 1 1 0 1 0 8 0 amappl10 152 60 0 50 1 0 1 1 0 8 0 amappl9 144 268 0 268 1 1 0 1 0 8 0 amappl8 136 95 0 94 1 0 1 1 0 8 0 amappl7 128 139 0 127 1 0 1 1 0 8 0 amappl6 120 149 0 148 1 0 1 1 0 8 0 amappl5 112 94 0 86 1 0 1 1 0 8 0 amappl4 104 263 0 248 1 0 1 1 0 8 0 amappl3 96 2257 0 2160 3 0 3 3 0 8 0 amappl2 88 530 0 476 2 0 2 2 0 8 0 amappl1 80 10715 0 10170 13 1 12 13 0 8 0 amappl 88 3372 0 3227 4 0 4 4 0 92 0 uvmvnodes 80 99 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 7 0 7 1 1 0 1 0 8 0 dma128 128 255 0 255 2 1 1 1 0 8 1 dma64 64 8 0 8 2 1 1 1 0 8 1 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 10 0 2 1 0 1 1 0 8 0 uaddrrnd 24 554 0 526 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 554 0 526 1 0 1 1 0 8 0 vmmpekpl 168 6316 0 6281 2 0 2 2 0 8 0 vmmpepl 168 43437 0 41731 92 11 81 91 0 357 1 vmsppl 368 553 0 526 4 1 3 4 0 8 0 rwobjpl 40 15100 0 14167 13 2 11 13 0 8 0 pdppl 4096 1114 0 1052 98 32 66 82 0 8 4 pvpl 32 249625 0 241657 120 39 81 115 0 265 4 pmappl 216 553 0 526 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 369 0 48 10 0 10 10 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83484057) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff834c280d,ffffffff8352255f,3bb,ffffffff834fbd23) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c8ea6c0,ffffffff8347e20c) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:956 pppx_if_destroy(0,ffff80003c8ea6b8) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b92,1,2000,ffff80003c8f2a90) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003c900dd0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8063df3530,1,fffffd8007ffd618,ffff80003c8f2a90) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b967bd0,ffff80003c8f2a90) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffffd806b967bd0,ffff80003c8f2a90) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621 fdrop(fffffd806b967bd0,ffff80003c8f2a90) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd806b967bd0,ffff80003c8f2a90) at closef+0x190 sys/kern/kern_descrip.c:1265 fdfree(ffff80003c8f2a90) at fdfree+0x115 sys/kern/kern_descrip.c:1196 exit1(ffff80003c8f2a90,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c8f2a90,ffff80003c901130,ffff80003c901080) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003c901130) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80003c901130) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x781eb0ee5ff0, count: -16 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83484057) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff834c280d,ffffffff8352255f,3bb,ffffffff834fbd23) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c8ea6c0,ffffffff8347e20c) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:956 pppx_if_destroy(0,ffff80003c8ea6b8) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b92,1,2000,ffff80003c8f2a90) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003c900dd0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8063df3530,1,fffffd8007ffd618,ffff80003c8f2a90) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b967bd0,ffff80003c8f2a90) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffffd806b967bd0,ffff80003c8f2a90) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621 fdrop(fffffd806b967bd0,ffff80003c8f2a90) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd806b967bd0,ffff80003c8f2a90) at closef+0x190 sys/kern/kern_descrip.c:1265 fdfree(ffff80003c8f2a90) at fdfree+0x115 sys/kern/kern_descrip.c:1196 exit1(ffff80003c8f2a90,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c8f2a90,ffff80003c901130,ffff80003c901080) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003c901130) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80003c901130) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x781eb0ee5ff0, count: -16