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 83503 18842 0 0x2 0 0 syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833b5f47) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833f0e0d,ffffffff833fdd03,3bb,ffffffff83427d52) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff8000fffdef08,ffffffff833a767d) at refcnt_finalize+0x1db sys/kern/kern_synch.c:956 pppx_if_destroy(205b9a,ffff8000fffdef00) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff8000fffe9778) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003a7eaa70) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806c9c8870,2,fffffd80097fd3a8,ffff8000fffe9778) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd80679a6a48,ffff8000fffe9778) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd80679a6a48,ffff8000fffe9778) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd80679a6a48,ffff8000fffe9778) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd80679a6a48,ffff8000fffe9778) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff8000fffe9778) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff8000fffe9778,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000fffe9778,ffff80003a7eade0,ffff80003a7ead30) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff80003a7eadd0, 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(ffffffff833b5f47) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833f0e0d,ffffffff833fdd03,3bb,ffffffff83427d52) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff8000fffdef08,ffffffff833a767d) at refcnt_finalize+0x1db sys/kern/kern_synch.c:956 pppx_if_destroy(205b9a,ffff8000fffdef00) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff8000fffe9778) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003a7eaa70) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806c9c8870,2,fffffd80097fd3a8,ffff8000fffe9778) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd80679a6a48,ffff8000fffe9778) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd80679a6a48,ffff8000fffe9778) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd80679a6a48,ffff8000fffe9778) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd80679a6a48,ffff8000fffe9778) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff8000fffe9778) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff8000fffe9778,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000fffe9778,ffff80003a7eade0,ffff80003a7ead30) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003a7eade0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003a7eade0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x78c809c27db0, count: -16 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff80003a7ea840 rbx 0xffff8000299dee07 rdx 0 rcx 0xffff8000fffe9778 rax 0xffff8000299ddff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0x5fe209ccc03d05ba r11 0x9b2a21a07431074e r12 0xffff8000299dec08 r13 0 r14 0 r15 0x1 rip 0xffffffff81262665 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003a7ea830 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor) tid=268895 pid=28479 tcnt=0 stat=onproc flags process=1008 proc=2000 runpri=32, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0xffff8000fffe9778 scnt=-1 ecnt=1 forw=0xffffffffffffffff, list=0xffff8000fffe9a10,0xffff8000fffe8fc0 process=0xffff8000fffe7040 user=0xffff80003a7e5000, vmspace=0xfffffd800dbad3f0 estcpu=0, cpticks=11, pctcpu=0.9, user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 62738 189417 80025 0 2 0 syz-executor 62738 442825 80025 0 2 0x4000000 syz-executor 8629 504989 7186 0 2 0 syz-executor 8629 16613 7186 0 3 0x4000000 smrbar syz-executor 75766 316964 26425 0 2 0 syz-executor 75766 15510 26425 0 3 0x4000080 fsleep syz-executor 10214 96996 29670 0 2 0xc80 syz-executor 10214 480712 29670 0 3 0x4000080 fifow syz-executor 10214 76811 29670 0 3 0x4000080 fsleep syz-executor 70852 119660 77806 0 2 0xc80 syz-executor 70852 304007 77806 0 3 0x4000080 lockf syz-executor 70852 235062 77806 0 3 0x4000080 lockf syz-executor 70852 245853 77806 0 3 0x4000080 fsleep syz-executor 72166 300110 18842 0 2 0x2 syz-executor 26425 300641 18842 0 2 0xc82 syz-executor 7186 250962 18842 0 2 0xc82 syz-executor 5533 6136 18842 0 2 0xc82 syz-executor 29670 74170 18842 0 2 0xc82 syz-executor 80025 138206 18842 0 2 0xc82 syz-executor 27544 257896 18842 0 2 0x2 syz-executor 77806 386711 18842 0 3 0x82 nanoslp syz-executor 18842 83503 93933 0 7 0x2 syz-executor 93933 320200 41995 0 3 0x10008a sigsusp ksh 41995 208491 62087 0 3 0x98 kqread sshd-session 62087 67175 20979 0 3 0x92 kqread sshd-session 72767 137835 1 0 3 0x100083 ttyin getty 20979 208735 1 0 3 0x88 kqread sshd 37539 33433 38728 74 2 0x1100012 pflogd 38728 326401 1 0 3 0x80 sbwait pflogd 9881 23717 56328 73 3 0x1100090 kqread syslogd 56328 9562 1 0 3 0x100082 sbwait syslogd 85130 399800 1 0 3 0x100080 kqread resolvd 93844 331143 67805 77 3 0x100092 kqread dhcpleased 89982 269076 67805 77 3 0x100092 kqread dhcpleased 67805 328636 1 0 3 0x80 kqread dhcpleased 20678 523097 0 0 2 0x40014200 smr 1209 153034 0 0 2 0x14200 zerothread 67337 282063 0 0 3 0x14200 aiodoned aiodoned 57482 93136 0 0 3 0x14200 syncer update 32171 43390 0 0 3 0x14200 cleaner cleaner 9428 173630 0 0 3 0x14200 reaper reaper 29302 263671 0 0 3 0x14200 pgdaemon pagedaemon 98316 516538 0 0 3 0x14200 bored viomb 25949 128547 0 0 3 0x40014200 acpi0 acpi0 73198 148631 0 0 3 0x40014200 idle1 98247 419698 0 0 3 0x14200 bored softnet1 9374 384878 0 0 3 0x14200 bored softnet0 33284 473741 0 0 3 0x14200 smrbar systqmp 6239 127914 0 0 3 0x14200 bored systq 9277 33390 0 0 2 0x14200 softclockmp 26399 292513 0 0 3 0x40014200 tmoslp softclock 88614 61903 0 0 3 0x40014200 idle0 1 426644 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 27544 (syz-executor) thread 0xffff8000ffffdc90 (257896) exclusive rrwlock inode r = 0 (0xfffffd8067ad5580) #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+0xbd sys/kern/vfs_vops.c:527 #4 ufs_ihashins+0x4f ufs_ihash sys/ufs/ufs/ufs_ihash.c:-1 [inline] #4 ufs_ihashins+0x4f sys/ufs/ufs/ufs_ihash.c:159 #5 ffs_vget+0x187 sys/ufs/ffs/ffs_vfsops.c:1232 #6 ffs_inode_alloc+0x279 sys/ufs/ffs/ffs_alloc.c:393 #7 ufs_mkdir+0xfc sys/ufs/ufs/ufs_vnops.c:1112 #8 VOP_MKDIR+0x101 sys/kern/vfs_vops.c:394 #9 domkdirat+0x179 sys/kern/vfs_syscalls.c:3113 #10 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #10 syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 #11 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd80708198e8) #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+0xbd sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570 #5 vfs_lookup+0x11c sys/kern/vfs_lookup.c:-1 #6 namei+0x7ca sys/kern/vfs_lookup.c:250 #7 domkdirat+0x8b sys/kern/vfs_syscalls.c:3098 #8 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #8 syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 #9 Xsyscall+0x128 Process 33284 (systqmp) thread 0xffff8000ffffe530 (473741) shared rwlock systqmp r = 0 (0xffffffff837c8748) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 taskq_thread+0x12a sys/kern/kern_task.c:442 #2 proc_trampoline+0x10 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10200 11096K 11219K 166960K 11324 0 pcb 18 12K 12K 166960K 32 0 rtable 199 6K 6K 166960K 357 0 pf 36 18K 18K 166960K 52 0 ifaddr 41 7K 7K 166960K 49 0 ifgroup 56 2K 2K 166960K 65 0 sysctl 1 1K 9K 166960K 5 0 counters 72 37K 37K 166960K 76 0 ioctlops 0 0K 4K 166960K 1489 0 iov 0 0K 4K 166960K 1 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1343 84K 84K 166960K 1383 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 1K 166960K 2 0 VM map 2 1K 1K 166960K 2 0 sem 5 0K 0K 166960K 5 0 dirhash 12 2K 2K 166960K 12 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 16 57K 93K 166960K 163 0 proc 71 115K 164K 166960K 530 0 subproc 72 4K 4K 166960K 72 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 in_multi 89 6K 7K 166960K 103 0 ether_multi 1 0K 0K 166960K 1 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 49 228K 228K 166960K 49 0 exec 0 0K 1K 166960K 375 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 167K 177K 166960K 3327 0 UVM aobj 3 2K 2K 166960K 3 0 pinsyscall 42 84K 106K 166960K 1287 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 1 0K 0K 166960K 1 0 NDP 26 1K 2K 166960K 30 0 temp 38 8670K 8734K 166960K 4193 0 kqueue 15 22K 28K 166960K 31 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 34 0 31 1 0 1 1 0 8 0 rtentry 176 113 0 23 5 0 5 5 0 8 0 unpcb 144 47 0 26 1 0 1 1 0 8 0 syncache 336 3 0 3 1 0 1 1 0 8 1 tcpcb 736 11 0 7 1 0 1 1 0 8 0 arp 136 18 0 2 1 0 1 1 0 8 0 inpcb 328 92 0 82 2 0 2 2 0 8 0 nd6 152 24 0 3 1 0 1 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 mppekey 1024 1 0 0 1 0 1 1 0 8 0 ppxss 1192 1 0 0 1 0 1 1 0 8 0 pppxif 1504 1 0 0 1 0 1 1 0 8 0 pfstscr 40 2 0 2 1 0 1 1 0 8 1 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 pfstitem 24 18 0 0 1 0 1 1 0 8 0 pfstkey 128 20 0 2 1 0 1 1 0 8 0 pfstate 448 19 0 1 3 0 3 3 0 8 1 pfrule 1344 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 489 0 41 31 0 31 31 0 8 1 art_table 40 490 0 41 5 0 5 5 0 8 0 art_node 32 113 0 32 1 0 1 1 0 8 0 sysvmsgpl 40 1 0 0 1 0 1 1 0 8 0 semupl 112 1 0 0 1 0 1 1 0 8 0 semapl 112 3 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1610 0 96 95 0 95 95 0 8 0 ffsino 296 1610 0 96 117 0 117 117 0 8 0 nchpl 144 1829 0 125 64 0 64 64 0 8 0 vnodes 216 1709 0 0 95 0 95 95 0 8 0 namei 1024 5508 0 5507 2 0 2 2 0 8 1 percpumem 16 53 0 2 1 0 1 1 0 8 0 kstatmem 264 30 0 4 2 0 2 2 0 8 0 scxspl 216 5948 0 5948 3 1 2 2 1 8 2 plimitpl 152 72 0 53 1 0 1 1 0 8 0 sigapl 424 471 0 424 7 0 7 7 0 8 0 knotepl 120 513 0 0 16 0 16 16 0 8 0 kqueuepl 224 33 0 20 1 0 1 1 0 8 0 pipepl 344 119 0 92 3 0 3 3 0 8 0 fdescpl 528 455 0 424 3 0 3 3 0 8 0 filepl 160 1614 0 1384 10 0 10 10 0 8 0 lockfpl 104 23 0 17 1 0 1 1 0 8 0 lockfspl 48 9 0 5 1 0 1 1 0 8 0 sessionpl 144 22 0 13 1 0 1 1 0 8 0 pgrppl 48 30 0 13 1 0 1 1 0 8 0 ucredpl 104 90 0 76 1 0 1 1 0 8 0 zombiepl 144 426 0 424 1 0 1 1 0 8 0 processpl 1232 471 0 424 5 0 5 5 0 8 0 procpl 664 522 0 467 6 0 6 6 0 8 0 sockpl 752 175 0 141 5 0 5 5 0 8 1 mcl64k 65536 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 114 0 0 15 0 15 15 0 8 0 mcl2k 2048 24 0 0 3 0 3 3 0 8 0 mtagpl 96 3 0 0 1 0 1 1 0 8 0 mbufpl 256 153 0 0 10 0 10 10 0 8 0 bufpl 280 2348 0 131 159 0 159 159 0 8 0 anonpl 32 3856 0 0 32 0 32 32 0 246 0 amapchunkpl 152 9164 0 8660 22 0 22 22 0 158 1 amappl16 200 1861 0 1841 5 0 5 5 0 8 3 amappl15 192 9 0 9 1 0 1 1 0 8 1 amappl14 184 16 0 16 1 0 1 1 0 8 1 amappl13 176 437 0 436 1 0 1 1 0 8 0 amappl12 168 824 0 782 3 0 3 3 0 8 0 amappl11 160 5 0 5 1 0 1 1 0 8 1 amappl10 152 54 0 40 1 0 1 1 0 8 0 amappl9 144 245 0 245 1 0 1 1 0 8 1 amappl8 136 37 0 34 1 0 1 1 0 8 0 amappl7 128 77 0 76 1 0 1 1 0 8 0 amappl6 120 278 0 264 1 0 1 1 0 8 0 amappl5 112 88 0 78 1 0 1 1 0 8 0 amappl4 104 421 0 392 1 0 1 1 0 8 0 amappl3 96 1485 0 1376 4 1 3 3 0 8 0 amappl2 88 525 0 465 2 0 2 2 0 8 0 amappl1 80 9141 0 8550 14 0 14 14 0 8 0 amappl 88 2593 0 2426 5 0 5 5 0 92 0 uvmvnodes 80 98 0 0 2 0 2 2 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 2 0 0 1 0 1 1 0 8 0 uaddrrnd 24 455 0 424 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 455 0 424 1 0 1 1 0 8 0 vmmpekpl 168 5493 0 5454 2 0 2 2 0 8 0 vmmpepl 168 36985 0 35069 87 0 87 87 0 357 0 vmsppl 488 454 0 424 5 0 5 5 0 8 0 rwobjpl 80 13626 0 12605 24 0 24 24 0 8 1 pdppl 4096 918 0 848 98 12 86 86 0 8 16 pvpl 32 10624 0 0 86 0 86 86 0 265 0 pmappl 256 454 0 424 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 272 0 14 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff83844ff0) 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 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x25 kd_curproc sys/dev/kcov.c:584 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x25 sys/dev/kcov.c:153 __mp_lock(ffffffff838c9d80) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff838c9d80) at __mp_lock+0x1a3 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 kqueue_sleep(fffffd806f7f41c0,ffff80002a2d4bb0) at kqueue_sleep+0x181 sys/kern/kern_event.c:1612 kqueue_scan(ffff80002a2d4970,8,ffff80002a2d4870,ffff80002a2d4bb0,ffff80002a262a70,ffff80002a2d4b1c) at kqueue_scan+0x223 sys/kern/kern_event.c:1663 dopselect(ffff80002a262a70,32,7e70507bf6f0,0,0,ffff80002a2d4bb0,109612eae91ba460,ffff80002a2d4c50) at dopselect+0x53e sys/kern/sys_generic.c:691 sys_pselect(ffff80002a262a70,ffff80002a2d4d00,ffff80002a2d4c50) at sys_pselect+0x25a sys/kern/sys_generic.c:589 syscall(ffff80002a2d4d00) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2d4d00) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7e70507bf6a0, count: 1 ddb{0}> trace x86_ipi_db(ffffffff83844ff0) 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 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x25 kd_curproc sys/dev/kcov.c:584 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x25 sys/dev/kcov.c:153 __mp_lock(ffffffff838c9d80) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff838c9d80) at __mp_lock+0x1a3 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 kqueue_sleep(fffffd806f7f41c0,ffff80002a2d4bb0) at kqueue_sleep+0x181 sys/kern/kern_event.c:1612 kqueue_scan(ffff80002a2d4970,8,ffff80002a2d4870,ffff80002a2d4bb0,ffff80002a262a70,ffff80002a2d4b1c) at kqueue_scan+0x223 sys/kern/kern_event.c:1663 dopselect(ffff80002a262a70,32,7e70507bf6f0,0,0,ffff80002a2d4bb0,109612eae91ba460,ffff80002a2d4c50) at dopselect+0x53e sys/kern/sys_generic.c:691 sys_pselect(ffff80002a262a70,ffff80002a2d4d00,ffff80002a2d4c50) at sys_pselect+0x25a sys/kern/sys_generic.c:589 syscall(ffff80002a2d4d00) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2d4d00) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7e70507bf6a0, count: -14 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(ffffffff833b5f47) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833f0e0d,ffffffff833fdd03,3bb,ffffffff83427d52) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff8000fffdef08,ffffffff833a767d) at refcnt_finalize+0x1db sys/kern/kern_synch.c:956 pppx_if_destroy(205b9a,ffff8000fffdef00) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff8000fffe9778) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003a7eaa70) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806c9c8870,2,fffffd80097fd3a8,ffff8000fffe9778) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd80679a6a48,ffff8000fffe9778) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd80679a6a48,ffff8000fffe9778) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd80679a6a48,ffff8000fffe9778) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd80679a6a48,ffff8000fffe9778) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff8000fffe9778) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff8000fffe9778,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000fffe9778,ffff80003a7eade0,ffff80003a7ead30) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff80003a7eadd0, count: 0 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833b5f47) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833f0e0d,ffffffff833fdd03,3bb,ffffffff83427d52) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff8000fffdef08,ffffffff833a767d) at refcnt_finalize+0x1db sys/kern/kern_synch.c:956 pppx_if_destroy(205b9a,ffff8000fffdef00) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,2,2000,ffff8000fffe9778) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003a7eaa70) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806c9c8870,2,fffffd80097fd3a8,ffff8000fffe9778) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd80679a6a48,ffff8000fffe9778) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd80679a6a48,ffff8000fffe9778) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd80679a6a48,ffff8000fffe9778) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd80679a6a48,ffff8000fffe9778) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff8000fffe9778) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff8000fffe9778,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000fffe9778,ffff80003a7eade0,ffff80003a7ead30) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003a7eade0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003a7eade0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x78c809c27db0, count: -16