panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 959 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 15534 19131 0 0x2 0 1 ifconfig *397347 51421 0 0 0x4000000 0K syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff834c5c22) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff83507ae9,ffffffff8351663c,3bf,ffffffff8353f14b) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80002a2c3148,ffffffff834bef0a) at refcnt_finalize+0x1e7 sys/kern/kern_synch.c:960 pppx_if_destroy(ffff800036f95000,ffff80002a2c3140) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,81,2000,ffff800045fe6a88) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff800035fd0740) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8060777bd8,81,fffffd80097fd5b0,ffff800045fe6a88) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806d2dfc00,ffff800045fe6a88) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffffd806d2dfc00,ffff800045fe6a88) at vn_closefile+0x12b sys/kern/vfs_vnops.c:621 fdrop(fffffd806d2dfc00,ffff800045fe6a88) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd806d2dfc00,ffff800045fe6a88) at closef+0x192 sys/kern/kern_descrip.c:1265 sys_closefrom(ffff800045fe6a88,ffff800035fd0a10,ffff800035fd0960) at sys_closefrom+0x13c sys/kern/kern_descrip.c:1471 syscall(ffff800035fd0a10) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800035fd0a10) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xb9fc3d6d5b0, count: 1 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 959 ddb{0}> show kasan No such command ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff834c5c22) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff83507ae9,ffffffff8351663c,3bf,ffffffff8353f14b) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80002a2c3148,ffffffff834bef0a) at refcnt_finalize+0x1e7 sys/kern/kern_synch.c:960 pppx_if_destroy(ffff800036f95000,ffff80002a2c3140) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,81,2000,ffff800045fe6a88) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff800035fd0740) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8060777bd8,81,fffffd80097fd5b0,ffff800045fe6a88) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806d2dfc00,ffff800045fe6a88) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffffd806d2dfc00,ffff800045fe6a88) at vn_closefile+0x12b sys/kern/vfs_vnops.c:621 fdrop(fffffd806d2dfc00,ffff800045fe6a88) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd806d2dfc00,ffff800045fe6a88) at closef+0x192 sys/kern/kern_descrip.c:1265 sys_closefrom(ffff800045fe6a88,ffff800035fd0a10,ffff800035fd0960) at sys_closefrom+0x13c sys/kern/kern_descrip.c:1471 syscall(ffff800035fd0a10) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800035fd0a10) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xb9fc3d6d5b0, count: -14 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800035fd0500 rbx 0xffffffff839c4e0f cpu_info_full_primary+0x2e0f rdx 0xffff8000015fac40 rcx 0xffff800045fe6a88 rax 0xffffffff839c3ff0 cpu_info_full_primary+0x1ff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0x6e70e5dcafea4929 r11 0xda203a62ea333ec6 r12 0xffffffff839c4c10 cpu_info_full_primary+0x2c10 r13 0 r14 0 r15 0x1 rip 0xffffffff828c1e25 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff800035fd04f0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=397347 pid=51421 tcnt=4 stat=onproc flags process=0 proc=4000000 runpri=86, usrpri=86, slppri=16, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff800045fe74e8,0xffff800045fe6d30 process=0xffff800045fea208 user=0xffff800035fcb000, vmspace=0xfffffd800f5853f0 estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S PRLAGS PFLAGS WAIT COMMAND 19131 15534 96643 0 7 0x2 0 ifconfig 96643 294606 72083 0 3 0x100002 0x88 sigsusp sh 44119 410774 46175 0 2 0 0 syz-executor 44119 137589 46175 0 3 0 0x4000080 fsleep syz-executor 99376 41363 77730 0 2 0 0 syz-executor 99376 441808 77730 0 3 0 0x4000000 smrbar syz-executor 99376 101894 77730 0 3 0 0x4000080 fsleep syz-executor 51421 454186 84533 0 2 0 0 syz-executor 51421 100826 84533 0 3 0 0x4000080 sbwait syz-executor 51421 443019 84533 0 2 0 0x4000c80 syz-executor *51421 397347 84533 0 7 0 0x4000000 syz-executor 23087 284513 43657 0 2 0 0 syz-executor 23087 152516 43657 0 3 0 0x4000080 fsleep syz-executor 23087 374575 43657 0 3 0 0x4000080 fsleep syz-executor 23087 324688 43657 0 3 0 0x4000080 fsleep syz-executor 72083 168854 47042 0 3 0x2 0x80 wait syz-executor 43657 265943 47042 0 2 0x2 0xc80 syz-executor 77730 139144 47042 0 2 0x2 0xc80 syz-executor 46175 169172 47042 0 2 0x2 0xc80 syz-executor 40655 359247 47042 0 3 0x2 0x80 wait syz-executor 84533 126377 47042 0 2 0x2 0xc80 syz-executor 21550 270050 81494 0 3 0x100002 0x80 sbwait arp 81494 39381 19609 0 3 0x100002 0x88 sigsusp sh 19609 510143 47042 0 3 0x2 0x80 wait syz-executor 47042 82034 16666 0 3 0x2 0x80 wait syz-executor 16666 98983 69556 0 3 0x100002 0x88 sigsusp ksh 69556 455392 33745 0 3 0x10 0x88 kqread sshd-session 33745 243454 29238 0 3 0x12 0x80 kqread sshd-session 68602 367650 1 0 3 0x100003 0x80 ttyin getty 29238 300766 1 0 3 0 0x88 kqread sshd 44726 16127 92917 74 3 0x1100012 0x80 bpf pflogd 92917 364554 1 0 3 0 0x80 sbwait pflogd 2011 362446 73713 73 3 0x1100010 0x80 kqread syslogd 73713 338285 1 0 3 0x100002 0x80 sbwait syslogd 23772 429107 1 0 3 0x100000 0x80 kqread resolvd 84541 66439 80120 77 3 0x100012 0x80 kqread dhcpleased 71949 393043 80120 77 3 0x100012 0x80 kqread dhcpleased 80120 113453 1 0 3 0 0x80 kqread dhcpleased 27082 8047 0 0 3 0x14000 0x200 bored smr 80834 99961 0 0 2 0x14000 0x200 zerothread 10808 293982 0 0 3 0x14000 0x200 aiodoned aiodoned 50236 267662 0 0 3 0x14000 0x200 syncer update 40178 161516 0 0 3 0x14000 0x200 cleaner cleaner 68146 124741 0 0 3 0x14000 0x200 reaper reaper 44928 512788 0 0 3 0x14000 0x200 pgdaemon pagedaemon 17290 292903 0 0 3 0x14000 0x200 bored viomb 86770 380086 0 0 3 0x14000 0x40000200 acpi0 acpi0 73530 381630 0 0 3 0x14000 0x40000200 idle1 79155 4024 0 0 3 0x14000 0x200 bored softnet1 90284 283802 0 0 3 0x14000 0x200 bored softnet0 97902 207332 0 0 3 0x14000 0x200 bored systqmp 59684 167863 0 0 3 0x14000 0x200 bored systq 2167 300247 0 0 3 0x14000 0x200 tmoslp softclockmp 31682 131226 0 0 3 0x14000 0x40000200 tmoslp softclock 67225 478323 0 0 3 0x14000 0x40000200 idle0 1 48289 0 0 3 0x2 0x80 wait init 0 0 -1 0 3 0x10010000 0x200 scheduler swapper ddb{0}> show all locks Process 51421 (syz-executor) thread 0xffff800045fe6a88 (397347) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83a1f300) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 vn_closefile+0x41 sys/kern/vfs_vnops.c:614 #2 fdrop+0x121 sys/kern/kern_descrip.c:1281 #3 closef+0x192 sys/kern/kern_descrip.c:1265 #4 sys_closefrom+0x13c sys/kern/kern_descrip.c:1471 #5 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #5 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791 #6 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11062 12088K 12103K 166960K 12257 0 pcb 18 12K 12K 166960K 38 0 rtable 223 7K 8K 166960K 991 0 pf 44 19K 19K 166960K 101 0 ifaddr 43 7K 7K 166960K 138 0 ifgroup 64 2K 2K 166960K 154 0 sysctl 3 1K 9K 166960K 7 0 counters 76 37K 37K 166960K 126 0 ioctlops 0 0K 4K 166960K 1538 0 iov 0 0K 2K 166960K 3 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1292 81K 81K 166960K 1635 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 8 0K 0K 166960K 10 0 dirhash 12 2K 2K 166960K 18 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 19 69K 97K 166960K 572 0 sigio 0 0K 0K 166960K 1 0 proc 79 131K 164K 166960K 1178 0 subproc 72 4K 4K 166960K 270 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 23 0 in_multi 86 5K 6K 166960K 338 0 ether_multi 1 0K 0K 166960K 3 0 mrt 1 0K 0K 166960K 12 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 55 254K 254K 166960K 55 0 exec 0 0K 1K 166960K 676 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 245 171K 184K 166960K 5965 0 UVM aobj 6 2K 2K 166960K 6 0 pinsyscall 45 90K 109K 166960K 2289 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 3 0 NDP 19 0K 1K 166960K 94 0 temp 42 9119K 9134K 166960K 13586 0 kqueue 15 24K 25K 166960K 49 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 28 0 0 1 0 1 1 0 8 0 rtpcb 120 82 0 78 1 0 1 1 0 8 0 rtentry 176 343 0 243 5 0 5 5 0 8 0 unpcb 144 83 0 66 1 0 1 1 0 8 0 syncache 336 6 0 6 2 2 0 1 0 8 0 tcpcb 736 25 0 21 1 0 1 1 0 8 0 arp 136 61 0 44 1 0 1 1 0 8 0 inpcb 328 244 0 232 3 1 2 2 0 8 1 nd6 152 85 0 66 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 1 0 1 0 8 0 kcovpl 48 30 0 22 1 0 1 1 0 8 0 ppxss 1192 4 0 3 2 1 1 1 0 8 0 pppxif 1576 1 0 0 1 0 1 1 0 8 0 pfstscr 40 2 0 0 1 0 1 1 0 8 0 pffrag 232 1 0 0 1 0 1 1 0 482 0 pffrnode 88 1 0 0 1 0 1 1 0 8 0 pffrent 40 1 0 0 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 0 1 0 1 1 0 8 0 pfsrclim 320 1 0 1 1 1 0 1 0 8 0 pfstitem 24 42 0 2 1 0 1 1 0 8 0 pfstkey 128 42 0 2 2 0 2 2 0 8 0 pfstate 448 41 0 2 5 0 5 5 0 8 0 pfrule 1360 22 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1379 0 971 33 3 30 30 0 8 1 art_table 40 1380 0 971 5 0 5 5 0 8 0 art_node 32 343 0 251 1 0 1 1 0 8 0 sysvmsgpl 40 7 0 1 1 0 1 1 0 8 0 semapl 72 7 0 1 1 0 1 1 0 8 0 shmpl 120 3 0 0 1 0 1 1 0 8 0 dirhash 1024 21 0 4 3 0 3 3 0 8 0 dino2pl 256 1821 0 300 96 0 96 96 0 8 0 ffsino 296 1821 0 300 118 0 118 118 0 8 0 nchpl 144 2140 0 357 67 0 67 67 0 8 0 rtmask 32 2 0 2 1 1 0 1 0 8 0 vnodes 216 2149 0 0 120 0 120 120 0 8 0 namei 1024 10264 0 10264 6 4 2 3 0 8 2 percpumem 16 79 0 25 1 0 1 1 0 8 0 kstatmem 264 77 0 46 3 0 3 3 0 8 0 scsiplug 72 1 0 1 1 1 0 1 0 8 0 scxspl 216 7327 0 7327 4 3 1 3 1 8 1 plimitpl 152 59 0 41 1 0 1 1 0 8 0 sigapl 424 847 0 798 8 1 7 7 0 8 1 knotepl 120 340 0 0 11 0 11 11 0 8 0 kqueuepl 224 62 0 50 1 0 1 1 0 8 0 pipepl 344 201 0 174 4 0 4 4 0 8 1 fdescpl 528 830 0 797 3 0 3 3 0 8 0 filepl 160 2790 0 2565 10 0 10 10 0 8 0 lockfpl 104 80 0 78 1 0 1 1 0 8 0 lockfspl 48 35 0 33 1 0 1 1 0 8 0 sessionpl 144 51 0 42 1 0 1 1 0 8 0 pgrppl 48 82 0 65 1 0 1 1 0 8 0 ucredpl 104 243 0 230 1 0 1 1 0 8 0 zombiepl 144 800 0 798 1 0 1 1 0 8 0 processpl 1240 847 0 798 5 0 5 5 0 8 0 procpl 664 1139 0 1081 7 0 7 7 0 8 1 sockpl 752 416 0 383 5 1 4 4 0 8 0 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 119 0 0 15 0 15 15 0 8 0 mcl2k 2048 35 0 0 5 0 5 5 0 8 0 mextrefs 64 34 0 0 1 0 1 1 0 8 0 mtagpl 96 1 0 0 1 0 1 1 0 8 0 mbufpl 256 321 0 0 21 0 21 21 0 8 0 bufpl 272 2549 0 105 163 0 163 163 0 8 0 anonpl 32 7397 0 0 60 0 60 60 0 247 0 amapchunkpl 152 16581 0 16082 32 11 21 31 0 158 1 amappl16 200 1845 0 1828 18 9 9 14 0 8 8 amappl15 192 6 0 6 1 1 0 1 0 8 0 amappl14 184 690 0 687 1 0 1 1 0 8 0 amappl13 176 169 0 156 1 0 1 1 0 8 0 amappl12 168 1166 0 1133 2 0 2 2 0 8 0 amappl11 160 1 0 1 1 1 0 1 0 8 0 amappl10 152 65 0 51 1 0 1 1 0 8 0 amappl9 144 294 0 294 1 1 0 1 0 8 0 amappl8 136 223 0 220 1 0 1 1 0 8 0 amappl7 128 188 0 174 1 0 1 1 0 8 0 amappl6 120 395 0 389 1 0 1 1 0 8 0 amappl5 112 98 0 87 1 0 1 1 0 8 0 amappl4 104 357 0 332 1 0 1 1 0 8 0 amappl3 96 2969 0 2864 3 0 3 3 0 8 0 amappl2 88 866 0 787 2 0 2 2 0 8 0 amappl1 80 13570 0 12933 17 2 15 16 0 8 1 amappl 88 4858 0 4692 5 0 5 5 0 92 0 uvmvnodes 80 102 0 0 3 0 3 3 0 8 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 5 0 0 1 0 1 1 0 8 0 uaddrrnd 24 830 0 797 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 830 0 797 1 0 1 1 0 8 0 vmmpekpl 168 8626 0 8562 3 0 3 3 0 8 0 vmmpepl 168 62280 0 60324 92 2 90 90 0 357 4 vmsppl 488 829 0 797 5 0 5 5 0 8 0 rwobjpl 80 20514 0 19411 29 2 27 27 0 8 4 pdppl 4096 1667 0 1594 123 48 75 87 0 8 2 pvpl 32 14411 0 0 118 1 117 117 0 265 0 pmappl 256 829 0 797 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 484 0 60 13 0 13 13 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(ffffffff834c5c22) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff83507ae9,ffffffff8351663c,3bf,ffffffff8353f14b) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80002a2c3148,ffffffff834bef0a) at refcnt_finalize+0x1e7 sys/kern/kern_synch.c:960 pppx_if_destroy(ffff800036f95000,ffff80002a2c3140) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,81,2000,ffff800045fe6a88) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff800035fd0740) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8060777bd8,81,fffffd80097fd5b0,ffff800045fe6a88) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806d2dfc00,ffff800045fe6a88) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffffd806d2dfc00,ffff800045fe6a88) at vn_closefile+0x12b sys/kern/vfs_vnops.c:621 fdrop(fffffd806d2dfc00,ffff800045fe6a88) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd806d2dfc00,ffff800045fe6a88) at closef+0x192 sys/kern/kern_descrip.c:1265 sys_closefrom(ffff800045fe6a88,ffff800035fd0a10,ffff800035fd0960) at sys_closefrom+0x13c sys/kern/kern_descrip.c:1471 syscall(ffff800035fd0a10) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800035fd0a10) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xb9fc3d6d5b0, count: -14 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffff80002999dff0) 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(ffffffff83a1eb00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff83a1eb00) at __mp_lock+0x192 sys/kern/kern_lock.c:173 vn_closefile(fffffd806f130790,ffff800045fe6d20) at vn_closefile+0x41 sys/kern/vfs_vnops.c:614 fdrop(fffffd806f130790,ffff800045fe6d20) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd806f130790,ffff800045fe6d20) at closef+0x192 sys/kern/kern_descrip.c:1265 syscall(ffff800035fdcb40) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800035fdcb40) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x70bc90881830, count: 6 ddb{1}> trace x86_ipi_db(ffff80002999dff0) 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(ffffffff83a1eb00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff83a1eb00) at __mp_lock+0x192 sys/kern/kern_lock.c:173 vn_closefile(fffffd806f130790,ffff800045fe6d20) at vn_closefile+0x41 sys/kern/vfs_vnops.c:614 fdrop(fffffd806f130790,ffff800045fe6d20) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(fffffd806f130790,ffff800045fe6d20) at closef+0x192 sys/kern/kern_descrip.c:1265 syscall(ffff800035fdcb40) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800035fdcb40) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x70bc90881830, count: -9