panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_synch.c", line 951 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(ffffffff8333d57e) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff83378eda,ffffffff833d5d1b,3b7,ffffffff833af85d) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80002cd2ab48,ffffffff83331335) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:952 pppx_if_destroy(205b92,ffff80002cd2ab40) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b92,41,2000,ffff80002a822fa8) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff8000395675f0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806af0fde0,41,fffffd8007bfb680,ffff80002a822fa8) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806ba38da0,ffff80002a822fa8) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806ba38da0,ffff80002a822fa8) at vn_closefile+0x11d sys/kern/vfs_vnops.c:615 fdrop(fffffd806ba38da0,ffff80002a822fa8) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806ba38da0,ffff80002a822fa8) at closef+0x190 sys/kern/kern_descrip.c:1264 fdfree(ffff80002a822fa8) at fdfree+0x115 sys/kern/kern_descrip.c:1195 exit1(ffff80002a822fa8,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80002a822fa8,ffff800039567950,ffff8000395678a0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff800039567940, 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 951 ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8333d57e) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff83378eda,ffffffff833d5d1b,3b7,ffffffff833af85d) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80002cd2ab48,ffffffff83331335) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:952 pppx_if_destroy(205b92,ffff80002cd2ab40) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b92,41,2000,ffff80002a822fa8) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff8000395675f0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806af0fde0,41,fffffd8007bfb680,ffff80002a822fa8) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806ba38da0,ffff80002a822fa8) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806ba38da0,ffff80002a822fa8) at vn_closefile+0x11d sys/kern/vfs_vnops.c:615 fdrop(fffffd806ba38da0,ffff80002a822fa8) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806ba38da0,ffff80002a822fa8) at closef+0x190 sys/kern/kern_descrip.c:1264 fdfree(ffff80002a822fa8) at fdfree+0x115 sys/kern/kern_descrip.c:1195 exit1(ffff80002a822fa8,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80002a822fa8,ffff800039567950,ffff8000395678a0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff800039567950) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff800039567950) at syscall+0x962 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7573ec324bb0, count: -16 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff8000395673d0 rbx 0 rdx 0 rcx 0 rax 0xffff80002a822fa8 r8 0x101010101010101 r9 0x8080808080808080 r10 0xbb41c2a8d870d797 r11 0x86e21092f8c028b6 r12 0 r13 0 r14 0 r15 0x1 rip 0xffffffff81a58635 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff8000395673c0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (syz-executor) tid=361321 pid=59072 tcnt=0 stat=onproc flags process=1008 proc=2000 runpri=32, usrpri=79, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0xffff80002a822fa8 scnt=-1 ecnt=1 forw=0xffffffffffffffff, list=0xffff80002a7f8550,0xffff80002a7f82c8 process=0xffff80002cd316d8 user=0xffff800039562000, vmspace=0xfffffd80671c2748 estcpu=29, cpticks=8, pctcpu=0.4, user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 17776 393575 20944 0 2 0 syz-executor 17776 446422 20944 0 3 0x4000080 fsleep syz-executor 72540 409948 28112 60928 2 0x10 syz-executor 72540 167095 28112 60928 3 0x4000090 fsleep syz-executor 18230 60432 14490 0 2 0 syz-executor 18230 314877 14490 0 3 0x4000080 lockf syz-executor 74029 6115 31216 0 2 0 syz-executor 74029 334218 31216 0 3 0x4000080 kqread syz-executor 74029 239682 31216 0 3 0x4000000 smrbar syz-executor 74029 385288 31216 0 2 0x4000000 syz-executor 86213 319307 35225 0 3 0x80 nanoslp syz-executor 86213 477033 35225 0 3 0x4000080 kqread syz-executor 86213 16267 35225 0 3 0x4000080 fsleep syz-executor 89724 468775 27105 0 3 0x80 nanoslp syz-executor 89724 264452 27105 0 3 0x4000080 semwait syz-executor 89724 262853 27105 0 3 0x4000080 fsleep syz-executor 71217 51735 26587 0 2 0 syz-executor 71217 496411 26587 0 3 0x4000080 lockf syz-executor 71217 218940 26587 0 3 0x4000080 lockf syz-executor 71217 183229 26587 0 3 0x4000080 lockf syz-executor 71217 7806 26587 0 3 0x4000080 fsleep syz-executor 82251 3931 0 0 3 0x14200 bored sosplice 27105 142896 70514 0 3 0x82 nanoslp syz-executor 35225 45770 70514 0 3 0x82 nanoslp syz-executor 26587 43772 70514 0 3 0x82 nanoslp syz-executor 28112 65832 70514 0 2 0xc82 syz-executor 83145 279399 70514 0 2 0xc82 syz-executor 31216 496999 70514 0 3 0x82 nanoslp syz-executor 14490 41691 70514 0 2 0xc82 syz-executor 20944 189212 70514 0 3 0x82 nanoslp syz-executor 70514 323257 32413 0 3 0x82 kqread syz-executor 32413 288897 1024 0 3 0x10008a sigsusp ksh 1024 95052 86371 0 3 0x98 kqread sshd-session 86371 485684 10191 0 3 0x92 kqread sshd-session 4930 436630 1 0 3 0x100083 ttyopn getty 10191 140910 1 0 3 0x88 kqread sshd 27042 299568 35094 73 3 0x1100090 kqread syslogd 35094 305971 1 0 3 0x100082 sbwait syslogd 57995 12844 1 0 3 0x100080 kqread resolvd 66412 413926 29370 77 3 0x100092 kqread dhcpleased 8584 72627 29370 77 3 0x100092 kqread dhcpleased 29370 74256 1 0 3 0x80 kqread dhcpleased 14684 494232 0 0 2 0x14200 smr 59867 136506 0 0 2 0x14200 zerothread 59938 292260 0 0 3 0x14200 aiodoned aiodoned 96814 319482 0 0 3 0x14200 syncer update 86286 383768 0 0 3 0x14200 cleaner cleaner 50998 461377 0 0 3 0x14200 reaper reaper 96133 81581 0 0 3 0x14200 pgdaemon pagedaemon 16264 152909 0 0 3 0x14200 bored viomb 12215 64264 0 0 3 0x40014200 acpi0 acpi0 75483 464709 0 0 3 0x14200 bored softnet7 57356 277527 0 0 3 0x14200 bored softnet6 22242 137315 0 0 3 0x14200 bored softnet5 32654 170245 0 0 3 0x14200 bored softnet4 93784 242184 0 0 3 0x14200 bored softnet3 38423 510833 0 0 3 0x14200 bored softnet2 40401 331059 0 0 3 0x14200 bored softnet1 30105 81700 0 0 3 0x14200 bored softnet0 4957 397285 0 0 3 0x14200 bored systqmp 5181 452026 0 0 3 0x14200 bored systq 15245 11075 0 0 3 0x40014200 tmoslp softclock 56344 31073 0 0 3 0x40014200 idle0 1 494083 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 10196 11042K 12139K 166960K 11984 0 pcb 17 15K 23K 166960K 182 0 rtable 205 8K 8K 166960K 319 0 pf 37 14K 16K 166960K 129 0 ifaddr 44 7K 7K 166960K 61 0 ifgroup 59 2K 2K 166960K 81 0 sysctl 4 1K 9K 166960K 10 0 counters 35 18K 18K 166960K 85 0 ioctlops 0 0K 4K 166960K 332 0 iov 0 0K 12K 166960K 44 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1471 92K 93K 166960K 1737 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 10 0K 0K 166960K 11 0 dirhash 12 2K 2K 166960K 15 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 97K 166960K 384 0 sigio 0 0K 0K 166960K 3 0 proc 60 59K 124K 166960K 500 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 95 0 in_multi 99 7K 7K 166960K 110 0 ether_multi 1 0K 0K 166960K 3 0 mrt 1 0K 0K 166960K 5 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 121 546K 546K 166960K 121 0 exec 0 0K 1K 166960K 357 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 250 164K 178K 166960K 5100 0 UVM aobj 4 2K 2K 166960K 5 0 pinsyscall 39 78K 96K 166960K 1416 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 1K 166960K 29 0 NDP 13 0K 2K 166960K 40 0 temp 46 8632K 8696K 166960K 14217 0 kqueue 16 26K 30K 166960K 68 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 48 0 45 1 0 1 1 0 8 0 rtentry 136 103 0 19 3 0 3 3 0 8 0 unpcb 144 546 0 531 6 0 6 6 0 8 5 syncache 336 6 0 6 1 0 1 1 0 8 1 tcpqe 32 1 0 1 1 0 1 1 0 8 1 tcpcb 736 168 0 161 7 0 7 7 0 8 5 arp 88 11 0 1 1 0 1 1 0 8 0 ipq 40 1 0 0 1 0 1 1 0 8 0 ipqe 40 1 0 0 1 0 1 1 0 8 0 inpcb 328 623 0 546 9 0 9 9 0 8 2 ip6q 72 2 0 0 1 0 1 1 0 8 0 ip6af 40 2 0 0 1 0 1 1 0 8 0 nd6 104 19 0 2 1 0 1 1 0 8 0 pkpcb 40 3 0 3 1 0 1 1 0 8 1 kcovpl 48 8 0 0 1 0 1 1 0 8 0 ppxss 1072 51 0 50 1 0 1 1 0 8 0 pppxif 1384 2 0 1 1 0 1 1 0 8 0 pfstscr 40 1 0 0 1 0 1 1 0 8 0 pfrktable 1344 1 0 1 1 0 1 1 0 8 1 pfstitem 24 2 0 0 1 0 1 1 0 8 0 pfstkey 128 2 0 0 1 0 1 1 0 8 0 pfstate 384 1 0 0 1 0 1 1 0 8 0 pfrule 1344 65 0 64 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 256 511 0 78 29 0 29 29 0 8 1 art_table 40 512 0 78 5 0 5 5 0 8 0 art_node 32 102 0 28 1 0 1 1 0 8 0 sysvmsgpl 40 5 0 2 1 0 1 1 0 8 0 semapl 112 9 0 1 1 0 1 1 0 8 0 shmpl 112 2 0 1 1 0 1 1 0 8 0 dirhash 1024 19 0 2 3 0 3 3 0 8 0 dino2pl 256 2112 0 605 95 0 95 95 0 8 0 ffsino 256 2112 0 605 95 0 95 95 0 8 0 nchpl 144 2645 0 959 63 0 63 63 0 8 0 rtmask 32 4 0 4 1 0 1 1 0 8 1 uvmvnodes 80 2413 0 0 50 0 50 50 0 8 0 vnodes 216 2413 0 0 135 0 135 135 0 8 0 namei 1024 8997 0 8997 2 0 2 2 0 8 2 kstatmem 264 48 0 22 3 0 3 3 0 8 1 scsiplug 72 4 0 4 1 0 1 1 0 8 1 scxspl 216 9866 0 9866 8 0 8 8 1 8 8 plimitpl 152 72 0 55 1 0 1 1 0 8 0 sigapl 424 668 0 617 7 0 7 7 0 8 1 knotepl 120 28062 0 28009 16 6 10 16 0 8 8 kqueuepl 184 130 0 117 1 0 1 1 0 8 0 pipepl 304 119 0 92 3 0 3 3 0 8 0 fdescpl 448 647 0 617 5 0 5 5 0 8 1 filepl 120 4493 0 4203 16 0 16 16 0 8 7 lockfpl 104 128 0 119 1 0 1 1 0 8 0 lockfspl 48 54 0 50 1 0 1 1 0 8 0 sessionpl 144 23 0 15 1 0 1 1 0 8 0 pgrppl 48 37 0 21 1 0 1 1 0 8 0 ucredpl 104 581 0 569 1 0 1 1 0 8 0 zombiepl 144 618 0 617 1 0 1 1 0 8 0 processpl 1168 668 0 617 5 0 5 5 0 8 1 procpl 664 1056 0 991 7 0 7 7 0 8 1 sosppl 168 3 0 3 1 0 1 1 0 8 1 sockpl 552 1291 0 1196 17 0 17 17 0 8 10 mcl64k 65536 14 0 14 1 0 1 1 0 8 1 mcl16k 16384 2 0 2 1 0 1 1 0 8 1 mcl8k 8192 6 0 6 1 0 1 1 0 8 1 mcl4k 4096 2765 0 2715 13 0 13 13 0 8 5 mcl2k 2048 569 0 564 2 0 2 2 0 8 1 mtagpl 96 9 0 6 1 0 1 1 0 8 0 mbufpl 256 6573 0 6338 15 0 15 15 0 8 0 bufpl 280 3813 0 117 264 0 264 264 0 8 0 anonpl 24 131723 0 128403 39 0 39 39 0 187 8 amapchunkpl 152 16841 0 16294 34 0 34 34 0 158 10 amappl16 200 2307 0 2277 8 0 8 8 0 8 3 amappl15 192 4 0 4 1 0 1 1 0 8 1 amappl14 184 102 0 92 1 0 1 1 0 8 0 amappl13 176 53 0 53 1 0 1 1 0 8 1 amappl12 168 1262 0 1232 3 0 3 3 0 8 1 amappl11 160 44 0 34 1 0 1 1 0 8 0 amappl10 152 22 0 22 1 0 1 1 0 8 1 amappl9 144 254 0 254 1 0 1 1 0 8 1 amappl8 136 23 0 22 1 0 1 1 0 8 0 amappl7 128 98 0 88 1 0 1 1 0 8 0 amappl6 120 173 0 170 1 0 1 1 0 8 0 amappl5 112 112 0 106 1 0 1 1 0 8 0 amappl4 104 295 0 280 1 0 1 1 0 8 0 amappl3 96 2825 0 2704 4 0 4 4 0 8 0 amappl2 88 630 0 576 2 0 2 2 0 8 0 amappl1 80 9302 0 8753 14 0 14 14 0 8 0 amappl 88 4394 0 4209 5 0 5 5 0 92 0 dma4096 4096 1 0 1 1 0 1 1 0 8 1 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 6 0 6 1 0 1 1 0 8 1 dma128 128 255 0 255 1 0 1 1 0 8 1 dma64 64 6 0 6 1 0 1 1 0 8 1 dma32 32 7 0 7 1 0 1 1 0 8 1 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 72 4 0 1 1 0 1 1 0 8 0 uaddrrnd 24 647 0 617 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 647 0 617 1 0 1 1 0 8 0 vmmpekpl 168 6646 0 6619 2 0 2 2 0 8 0 vmmpepl 168 47413 0 45496 90 0 90 90 0 357 5 vmsppl 368 646 0 617 4 0 4 4 0 8 1 rwobjpl 40 17598 0 14313 34 0 34 34 0 8 0 pdppl 4096 1301 0 1234 101 32 69 83 0 8 2 pvpl 32 317497 0 308234 104 0 104 104 0 265 16 pmappl 216 646 0 617 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 384 0 32 11 0 11 11 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(ffffffff8333d57e) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff83378eda,ffffffff833d5d1b,3b7,ffffffff833af85d) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80002cd2ab48,ffffffff83331335) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:952 pppx_if_destroy(205b92,ffff80002cd2ab40) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b92,41,2000,ffff80002a822fa8) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff8000395675f0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806af0fde0,41,fffffd8007bfb680,ffff80002a822fa8) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806ba38da0,ffff80002a822fa8) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806ba38da0,ffff80002a822fa8) at vn_closefile+0x11d sys/kern/vfs_vnops.c:615 fdrop(fffffd806ba38da0,ffff80002a822fa8) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806ba38da0,ffff80002a822fa8) at closef+0x190 sys/kern/kern_descrip.c:1264 fdfree(ffff80002a822fa8) at fdfree+0x115 sys/kern/kern_descrip.c:1195 exit1(ffff80002a822fa8,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80002a822fa8,ffff800039567950,ffff8000395678a0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff800039567950) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff800039567950) at syscall+0x962 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7573ec324bb0, 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(ffffffff8333d57e) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff83378eda,ffffffff833d5d1b,3b7,ffffffff833af85d) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80002cd2ab48,ffffffff83331335) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:952 pppx_if_destroy(205b92,ffff80002cd2ab40) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b92,41,2000,ffff80002a822fa8) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff8000395675f0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806af0fde0,41,fffffd8007bfb680,ffff80002a822fa8) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806ba38da0,ffff80002a822fa8) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806ba38da0,ffff80002a822fa8) at vn_closefile+0x11d sys/kern/vfs_vnops.c:615 fdrop(fffffd806ba38da0,ffff80002a822fa8) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806ba38da0,ffff80002a822fa8) at closef+0x190 sys/kern/kern_descrip.c:1264 fdfree(ffff80002a822fa8) at fdfree+0x115 sys/kern/kern_descrip.c:1195 exit1(ffff80002a822fa8,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80002a822fa8,ffff800039567950,ffff8000395678a0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff800039567950) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff800039567950) at syscall+0x962 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7573ec324bb0, count: -16