panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 776 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *294211 75255 0 0x14000 0x40000200 0K softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff825ab874) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff8261f5b6,ffffffff8261d39b,308,ffffffff825785b7) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8065fb37f8) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff82ae7120) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82ae7120) at timeout_run+0xcc sys/kern/kern_timeout.c:641 softclock_thread(ffff8000211e9260) at softclock_thread+0x134 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: 8 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 "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 776 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff825ab874) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff8261f5b6,ffffffff8261d39b,308,ffffffff825785b7) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8065fb37f8) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff82ae7120) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82ae7120) at timeout_run+0xcc sys/kern/kern_timeout.c:641 softclock_thread(ffff8000211e9260) at softclock_thread+0x134 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff8000211f4fc0 rbx 0xffffffff829d2b8f cpu_info_full_primary+0x2b8f rdx 0 rcx 0 rax 0xffff8000211e9260 r8 0x101010101010101 r9 0x8080808080808080 r10 0xd3a1c4fdceb1d5cf r11 0x6024c853030e65e5 r12 0xffffffff829d2990 cpu_info_full_primary+0x2990 r13 0 r14 0 r15 0x1 rip 0xffffffff8249e7d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000211f4fb0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=294211 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000211e97a0,0xffff8000211e8d30 process=0xffff8000ffffdd50 user=0xffff8000211f0000, vmspace=0xffffffff82b90668 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 90087 10851 0 0 3 0x14280 nfsidl nfsio 47123 38716 0 0 3 0x14280 nfsidl nfsio 66289 61923 0 0 3 0x14280 nfsidl nfsio 51280 438872 0 0 3 0x14280 nfsidl nfsio 89544 446140 0 0 3 0x14280 nfsidl nfsio 19278 502785 0 0 3 0x14280 nfsidl nfsio 46354 103504 0 0 3 0x14280 nfsidl nfsio 93672 67466 0 0 3 0x14280 nfsidl nfsio 23937 100614 0 0 3 0x14280 nfsidl nfsio 6886 131954 0 0 3 0x14280 nfsidl nfsio 96447 296484 0 0 3 0x14280 nfsidl nfsio 86575 71053 0 0 3 0x14280 nfsidl nfsio 57587 512201 0 0 3 0x14280 nfsidl nfsio 34880 61929 0 0 3 0x14280 nfsidl nfsio 71908 130727 0 0 3 0x14280 nfsidl nfsio 25063 371965 0 0 3 0x14280 nfsidl nfsio 42395 254614 0 0 3 0x14280 nfsidl nfsio 74752 293781 0 0 3 0x14280 nfsidl nfsio 17513 326605 0 0 3 0x14280 nfsidl nfsio 35258 241693 0 0 3 0x14280 nfsidl nfsio 28881 32592 0 0 3 0x14200 bored sosplice 49475 446780 1 0 3 0x8a kqread sshd 4011 256336 18217 74 3 0x1100092 bpf pflogd 18217 256270 1 0 3 0x80 netio pflogd 40275 14965 96826 73 3 0x1100090 kqread syslogd 96826 88909 1 0 3 0x100082 netio syslogd 12740 417396 1 0 3 0x100080 kqread resolvd 52460 27602 83934 77 3 0x100092 kqread dhcpleased 87086 228858 83934 77 3 0x100092 kqread dhcpleased 83934 319946 1 0 3 0x80 kqread dhcpleased 48524 247259 0 0 3 0x14200 bored smr 45532 373135 0 0 3 0x14200 pgzero zerothread 29532 502808 0 0 3 0x14200 aiodoned aiodoned 95289 26342 0 0 3 0x14200 syncer update 26586 284997 0 0 3 0x14200 cleaner cleaner 83958 220071 0 0 3 0x14200 reaper reaper 87211 377205 0 0 3 0x14200 pgdaemon pagedaemon 37476 144245 0 0 3 0x14200 bored viomb 38128 515071 0 0 3 0x40014200 acpi0 acpi0 22683 4149 0 0 7 0x40014200 idle1 52030 268075 0 0 3 0x14200 bored softnet 50349 174495 0 0 3 0x14200 bored softnet 96373 85172 0 0 3 0x14200 bored softnet 45689 434381 0 0 3 0x14200 bored softnet 95262 149871 0 0 3 0x14200 bored systqmp 98315 10719 0 0 3 0x14200 bored systq *75255 294211 0 0 7 0x40014200 softclock 87467 17748 0 0 3 0x40014200 idle0 1 102827 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10238 6505K 7000K 78643K 24639 0 pcb 13 22K 26K 78643K 1942 0 rtable 79 13K 17K 78643K 2554 0 ifaddr 48 13K 20K 78643K 746 0 sysctl 3 1K 5K 78643K 8 0 counters 48 34K 36K 78643K 658 0 ioctlops 0 0K 4K 78643K 3789 0 iov 0 0K 20K 78643K 1618 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1492 93K 93K 78643K 8676 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 89 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 967 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 2 4K 85K 78643K 8001 0 sigio 0 0K 0K 78643K 297 0 proc 65 79K 140K 78643K 2009 0 subproc 13 0K 6K 78643K 637 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 411 0 in_multi 18 1K 6K 78643K 695 0 ether_multi 1 0K 0K 78643K 32 0 mrt 1 0K 0K 78643K 25 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 277 1235K 1235K 78643K 277 0 exec 0 0K 1K 78643K 2418 0 pfkey data 0 0K 0K 78643K 3 0 tdb 3 0K 0K 78643K 3 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 8 62K 64K 78643K 10 0 UVM amap 136 275K 357K 78643K 56425 0 UVM aobj 131 8K 8K 78643K 154 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 183 0 NDP 10 0K 2K 78643K 264 0 temp 100 4700K 70238K 78643K 86991 0 kqueue 10 14K 28K 78643K 593 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 22 0 0 1 0 1 1 0 8 0 rtpcb 120 1120 0 1117 15 14 1 3 0 8 0 rtentry 112 706 0 685 4 0 4 4 0 8 0 unpcb 144 6544 0 6530 68 67 1 10 0 8 0 syncache 296 38 0 38 13 13 0 1 0 8 0 tcpqe 32 155 72 155 3 3 0 1 0 8 0 tcpcb 776 7344 0 7338 131 130 1 21 0 8 0 arp 120 115 0 111 1 0 1 1 0 8 0 inpcb 368 12871 0 12862 173 171 2 26 0 8 0 nd6 48 154 0 153 1 0 1 1 0 8 0 pkpcb 40 21 0 21 4 4 0 1 0 8 0 kcovpl 48 49 0 48 1 0 1 1 0 8 0 mppekey 1024 6 0 6 2 2 0 1 0 8 0 ppxss 1256 214 0 214 13 13 0 1 0 8 0 pppxif 1448 149 0 149 6 6 0 1 0 8 0 pfstscr 40 4 0 3 1 0 1 1 0 8 0 pffrag 232 65 0 65 6 6 0 1 0 482 0 pffrnode 88 65 0 65 6 6 0 1 0 8 0 pffrent 40 129 0 129 6 6 0 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 2 0 0 1 0 1 1 0 8 0 pfstkey 120 8 0 6 1 0 1 1 0 8 0 pfstate 384 4 0 3 1 0 1 1 0 8 0 rttmr 136 6 0 6 2 2 0 1 0 8 0 art_heap8 4096 4 0 3 4 3 1 2 0 8 0 art_heap4 256 3040 0 2914 45 19 26 29 0 8 9 art_table 32 3044 0 2917 4 0 4 4 0 8 0 art_node 16 702 0 684 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 965 0 955 1 0 1 1 0 8 0 shmpl 112 151 0 23 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 11772 0 10295 93 0 93 93 0 8 0 ffsino 272 11772 0 10295 99 0 99 99 0 8 0 nchpl 144 21855 0 20215 63 0 63 63 0 8 0 rtmask 32 3 0 3 1 1 0 1 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 82067 0 82067 10 9 1 2 0 8 1 percpumem 16 341 0 305 1 0 1 1 0 8 0 vcpupl 2048 51 0 0 7 0 7 7 0 8 0 vmpool 568 64 0 13 4 0 4 4 0 8 0 kstatmem 264 308 0 288 4 1 3 3 0 8 0 acpiwqpl 32 2 0 2 1 0 1 1 1 8 1 scsiplug 72 3 0 3 1 1 0 1 0 8 0 scxspl 216 64163 0 64163 28 27 1 8 0 8 1 plimitpl 152 664 0 658 1 0 1 1 0 8 0 sigapl 424 8280 0 8230 10 2 8 8 0 8 0 futexpl 64 66652 0 66652 2 2 0 1 0 8 0 knotepl 120 576 0 0 11 1 10 11 0 8 0 kqueuepl 216 1434 0 1428 29 28 1 5 0 8 0 pipepl 320 2781 0 2779 66 63 3 13 0 8 2 fdescpl 496 8242 0 8230 6 2 4 5 0 8 0 filepl 152 62137 0 62071 123 113 10 25 0 8 3 lockfpl 104 1332 0 1330 3 2 1 2 0 8 0 lockfspl 48 559 0 557 1 0 1 1 0 8 0 sessionpl 144 67 0 60 1 0 1 1 0 8 0 pgrppl 48 81 0 74 1 0 1 1 0 8 0 ucredpl 104 8144 0 8132 1 0 1 1 0 8 0 zombiepl 144 8231 0 8230 4 3 1 1 0 8 0 processpl 1072 8280 0 8230 5 0 5 5 0 8 0 procpl 672 22555 0 22505 11 2 9 10 0 8 0 srpgc 96 68 0 68 12 12 0 1 0 8 0 sosppl 168 48 0 48 10 10 0 1 0 8 0 sockpl 488 20564 0 20538 387 382 5 37 0 8 0 mcl64k 65536 18 0 0 3 0 3 3 0 8 0 mcl16k 16384 17 0 0 3 0 3 3 0 8 0 mcl12k 12288 25 0 0 2 0 2 2 0 8 0 mcl9k 9216 16 0 0 2 0 2 2 0 8 0 mcl8k 8192 20 0 0 3 0 3 3 0 8 0 mcl4k 4096 33 0 0 3 0 3 3 0 8 0 mcl2k2 2112 8 0 0 1 0 1 1 0 8 0 mcl2k 2048 509 0 0 62 10 52 62 0 8 0 mtagpl 96 568 0 0 12 0 12 12 0 8 0 mbufpl 256 2123 0 0 114 0 114 114 0 8 0 bufpl 288 15423 0 9089 453 0 453 453 0 8 0 anonpl 24 1730748 0 1728835 190 66 124 134 0 186 60 amapchunkpl 152 159120 0 159004 59 21 38 47 0 158 18 amappl16 200 16764 0 16750 89 59 30 42 0 8 20 amappl15 192 31 0 31 2 2 0 1 0 8 0 amappl14 184 343 0 334 2 0 2 2 0 8 0 amappl13 176 36 0 36 1 0 1 1 0 8 1 amappl12 168 979 0 979 1 0 1 1 0 8 1 amappl11 160 69 0 55 1 0 1 1 0 8 0 amappl10 152 96 0 95 1 0 1 1 0 8 0 amappl9 144 1033 0 1033 1 0 1 1 0 8 1 amappl8 136 522 0 518 4 0 4 4 0 8 2 amappl7 128 99 0 96 1 0 1 1 0 8 0 amappl6 120 783 0 774 2 1 1 2 0 8 0 amappl5 112 202 0 192 1 0 1 1 0 8 0 amappl4 104 1072 0 1056 2 1 1 2 0 8 0 amappl3 96 23758 0 23733 2 0 2 2 0 8 0 amappl2 88 9043 0 8998 3 1 2 3 0 8 0 amappl1 80 187160 0 186755 29 11 18 22 0 8 2 amappl 88 55589 0 55519 6 0 6 6 0 92 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 72 153 0 23 3 0 3 3 0 8 0 uaddrrnd 24 8306 0 8243 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 8306 0 8243 1 0 1 1 0 8 0 vmmpekpl 168 73562 0 73527 4 0 4 4 0 8 0 vmmpepl 168 773291 0 772273 302 158 144 156 0 357 51 vmsppl 368 8305 0 8243 9 1 8 8 0 8 0 rwobjpl 56 205774 0 199095 125 11 114 116 0 8 1 pdppl 4096 16619 0 16537 611 507 104 120 0 8 22 pvpl 32 3377749 0 3373468 410 196 214 259 0 265 101 pmappl 248 8305 0 8243 7 1 6 6 0 8 1 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1713 0 737 29 0 29 29 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff825ab874) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff8261f5b6,ffffffff8261d39b,308,ffffffff825785b7) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8065fb37f8) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff82ae7120) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82ae7120) at timeout_run+0xcc sys/kern/kern_timeout.c:641 softclock_thread(ffff8000211e9260) at softclock_thread+0x134 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020dd8ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 acpicpu_idle() at acpicpu_idle+0x312 sys/dev/acpi/acpicpu.c:1206 sched_idle(ffff800020dd8ff0) at sched_idle+0x417 sys/kern/kern_sched.c:175 end trace frame: 0x0, count: 10 ddb{1}> trace x86_ipi_db(ffff800020dd8ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 acpicpu_idle() at acpicpu_idle+0x312 sys/dev/acpi/acpicpu.c:1206 sched_idle(ffff800020dd8ff0) at sched_idle+0x417 sys/kern/kern_sched.c:175 end trace frame: 0x0, count: -5 ddb{1}> serialport: VM disconnected.