panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/main/kernel/sys/netinet/if_ether.c", line 716 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *113463 2172 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 __assert(ffffffff821e60c6,ffffffff821fd48f,2cc,ffffffff8216e00a) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd8038607cb8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825225e0) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffe9e0) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffe9e0) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: 9 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 kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/main/kernel/sys/netinet/if_ether.c", line 716 ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 __assert(ffffffff821e60c6,ffffffff821fd48f,2cc,ffffffff8216e00a) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd8038607cb8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825225e0) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffe9e0) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffe9e0) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014812a30 rbx 0xffff800014812ae0 rdx 0x2 rcx 0 rax 0 r8 0xffff8000148129f0 r9 0x1 r10 0 r11 0x67573c731d8922f7 r12 0x3000000008 r13 0xffff800014812a40 r14 0x100 r15 0x1 rip 0xffffffff811e4308 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800014812a20 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=113463 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffffec58,0xffff8000ffffe778 process=0xffff8000ffffcd80 user=0xffff80001480d000, vmspace=0xffffffff825a72b8 estcpu=1, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 23144 111077 90740 0 2 0x480 syz-executor.0 23144 457923 90740 0 3 0x4000080 netio syz-executor.0 23144 50036 90740 0 3 0x4000080 fsleep syz-executor.0 90740 34342 13701 0 2 0x482 syz-executor.0 87837 213503 13701 0 2 0x482 syz-executor.1 4232 465291 1 0 3 0x100083 ttyin getty 66702 450146 0 0 3 0x14200 bored sosplice 13701 19277 49450 0 3 0x82 thrsleep syz-fuzzer 13701 13638 49450 0 3 0x4000082 thrsleep syz-fuzzer 13701 255748 49450 0 3 0x4000082 thrsleep syz-fuzzer 13701 457272 49450 0 3 0x4000082 thrsleep syz-fuzzer 13701 287355 49450 0 3 0x4000082 thrsleep syz-fuzzer 13701 112216 49450 0 3 0x4000082 kqread syz-fuzzer 13701 171866 49450 0 3 0x4000082 thrsleep syz-fuzzer 13701 264865 49450 0 2 0x4000482 syz-fuzzer 49450 176251 37480 0 3 0x10008a pause ksh 37480 510809 74978 0 3 0x92 select sshd 74978 219031 1 0 3 0x80 select sshd 90489 1774 44032 73 3 0x100090 kqread syslogd 44032 300229 1 0 3 0x100082 netio syslogd 20496 511914 1 77 3 0x100090 poll dhclient 8050 56057 1 0 3 0x80 poll dhclient 72169 429836 0 0 3 0x14200 pgzero zerothread 83019 129667 0 0 3 0x14200 aiodoned aiodoned 97718 95675 0 0 3 0x14200 syncer update 17514 469050 0 0 3 0x14200 cleaner cleaner 20155 476525 0 0 3 0x14200 reaper reaper 18796 100572 0 0 3 0x14200 pgdaemon pagedaemon 75157 37341 0 0 3 0x14200 bored crynlk 12220 83590 0 0 3 0x14200 bored crypto 44163 97336 0 0 3 0x40014200 acpi0 acpi0 72243 487661 0 0 3 0x14200 bored softnet 9964 55834 0 0 3 0x14200 bored systqmp 97520 511977 0 0 3 0x14200 bored systq * 2172 113463 0 0 7 0x40014200 softclock 49949 357698 0 0 3 0x40014200 idle0 61406 173465 0 0 3 0x14200 bored smr 1 28529 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 Kern Lim devbuf 9572 7033K 7726K 78643K 15705 0 0 pcb 13 10K 12K 78643K 492 0 0 rtable 111 8K 8K 78643K 2004 0 0 ifaddr 82 17K 18K 78643K 472 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 123 0 0 iov 0 0K 36K 78643K 4306 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1230 77K 77K 78643K 3380 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 5K 78643K 35 0 0 VM map 14 3K 3K 78643K 19 0 0 sem 12 0K 1K 78643K 1862 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 5 13K 25K 78643K 2542 0 0 sigio 0 0K 0K 78643K 26 0 0 proc 49 38K 55K 78643K 1140 0 0 subproc 32 2K 2K 78643K 272 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 233 0 0 in_multi 24 1K 2K 78643K 296 0 0 ether_multi 1 0K 0K 78643K 24 0 0 mrt 0 0K 0K 78643K 11 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 84 371K 371K 78643K 84 0 0 exec 0 0K 1K 78643K 662 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 127 103K 107K 78643K 7166 0 0 UVM aobj 130 5K 5K 78643K 132 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 0K 78643K 455 0 0 NDP 20 0K 0K 78643K 153 0 0 temp 226 3544K 4184K 78643K 151556 0 0 kqueue 0 0K 0K 78643K 14 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 68 0 61 1 0 1 1 0 8 0 rtpcb 80 491 0 489 1 0 1 1 0 8 0 rtentry 112 325 0 284 2 0 2 2 0 8 0 unpcb 120 1197 0 1189 1 0 1 1 0 8 0 syncache 264 6 0 6 3 2 1 1 0 8 1 tcpqe 32 21 0 21 2 2 0 1 0 8 0 tcpcb 544 2261 0 2254 25 23 2 13 0 8 1 ipq 40 22 0 22 9 8 1 1 0 8 1 ipqe 40 221 0 221 9 8 1 1 0 8 1 inpcb 280 4004 0 3994 22 20 2 9 0 8 1 rttmr 72 4 0 3 3 2 1 1 0 8 0 ip6q 72 2 0 2 2 1 1 1 0 8 1 ip6af 40 5 0 5 2 1 1 1 0 8 1 nd6 48 37 0 35 1 0 1 1 0 8 0 pkpcb 40 16 0 16 3 3 0 1 0 8 0 ppxss 1128 43 0 43 8 7 1 1 0 8 1 art_heap8 4096 11 0 10 7 6 1 3 0 8 0 art_heap4 256 1265 0 1053 23 9 14 16 0 8 0 art_table 32 1276 0 1063 3 0 3 3 0 8 0 art_node 16 324 0 287 1 0 1 1 0 8 0 sysvmsgpl 40 29 0 19 1 0 1 1 0 8 0 semupl 112 5 0 5 1 1 0 1 0 8 0 semapl 112 1860 0 1850 1 0 1 1 0 8 0 shmpl 112 130 0 2 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 5421 0 4023 46 0 46 46 0 8 0 ffsino 240 5421 0 4023 83 0 83 83 0 8 0 nchpl 144 10427 0 8820 60 0 60 60 0 8 0 uvmvnodes 72 6908 0 0 126 0 126 126 0 8 0 vnodes 208 6908 0 0 364 0 364 364 0 8 0 namei 1024 35443 0 35443 3 2 1 1 0 8 1 vcpupl 1984 12 0 0 2 0 2 2 0 8 0 vmpool 520 17 0 5 1 0 1 1 0 8 0 scsiplug 64 3 0 3 2 2 0 1 0 8 0 scxspl 192 35933 0 35933 28 24 4 7 0 8 4 plimitpl 152 180 0 173 1 0 1 1 0 8 0 sigapl 432 2672 0 2659 2 0 2 2 0 8 0 futexpl 56 83199 0 83198 4 3 1 1 0 8 0 knotepl 112 704 0 685 2 1 1 2 0 8 0 kqueuepl 104 691 0 689 4 3 1 4 0 8 0 pipepl 112 2546 0 2527 10 9 1 2 0 8 0 fdescpl 424 2673 0 2659 2 0 2 2 0 8 0 filepl 120 24486 0 24388 17 13 4 11 0 8 1 lockfpl 104 1021 0 1019 1 0 1 1 0 8 0 lockfspl 48 303 0 301 1 0 1 1 0 8 0 sessionpl 112 32 0 22 1 0 1 1 0 8 0 pgrppl 48 136 0 126 1 0 1 1 0 8 0 ucredpl 96 2427 0 2420 1 0 1 1 0 8 0 zombiepl 144 2661 0 2660 1 0 1 1 0 8 0 processpl 864 2690 0 2660 4 0 4 4 0 8 0 procpl 632 5710 0 5671 5 1 4 5 0 8 0 sosppl 128 16 0 16 5 5 0 1 0 8 0 sockpl 384 5749 0 5729 36 31 5 14 0 8 3 mcl64k 65536 200 0 198 8 7 1 1 0 8 0 mcl16k 16384 28 0 28 13 12 1 1 0 8 1 mcl12k 12288 75 0 75 8 7 1 1 0 8 1 mcl9k 9216 43 0 43 9 8 1 1 0 8 1 mcl8k 8192 134 0 134 3 2 1 1 0 8 1 mcl4k 4096 260 0 260 4 3 1 1 0 8 1 mcl2k2 2112 22 0 22 8 8 0 1 0 8 0 mcl2k 2048 69543 0 69500 18 11 7 14 0 8 1 mtagpl 80 136 0 127 3 2 1 1 0 8 0 mbufpl 256 132617 0 132513 44 36 8 19 0 8 0 bufpl 256 19473 0 11898 481 7 474 474 0 8 0 anonpl 16 365768 0 345774 148 59 89 94 0 62 8 amapchunkpl 152 15324 0 15175 58 50 8 20 0 158 1 amappl16 192 16307 0 15199 139 75 64 67 0 8 8 amappl15 184 184 0 184 2 2 0 1 0 8 0 amappl14 176 202 0 197 1 0 1 1 0 8 0 amappl13 168 417 0 417 4 4 0 1 0 8 0 amappl12 160 659 0 655 1 0 1 1 0 8 0 amappl11 152 474 0 463 1 0 1 1 0 8 0 amappl10 144 37 0 36 5 4 1 1 0 8 0 amappl9 136 1337 0 1329 1 0 1 1 0 8 0 amappl8 128 866 0 826 3 1 2 2 0 8 0 amappl7 120 92 0 86 1 0 1 1 0 8 0 amappl6 112 466 0 456 1 0 1 1 0 8 0 amappl5 104 933 0 923 1 0 1 1 0 8 0 amappl4 96 3123 0 3097 1 0 1 1 0 8 0 amappl3 88 447 0 437 1 0 1 1 0 8 0 amappl2 80 19941 0 19874 3 1 2 3 0 8 0 amappl1 72 58110 0 57695 25 16 9 20 0 8 0 amappl 80 6201 0 6152 2 0 2 2 0 84 0 dma4096 4096 1 0 1 1 1 0 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 17 0 17 1 1 0 1 0 8 0 aobjpl 64 131 0 2 3 0 3 3 0 8 0 uaddrrnd 24 2690 0 2659 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2690 0 2659 1 0 1 1 0 8 0 vmmpekpl 168 21097 0 21065 2 0 2 2 0 8 0 vmmpepl 168 330289 0 328055 242 116 126 139 0 357 22 vmsppl 272 2672 0 2659 3 2 1 2 0 8 0 pdppl 4096 5386 0 5340 10 3 7 7 0 8 1 pvpl 32 937676 0 915039 364 144 220 319 0 265 37 pmappl 200 2689 0 2664 2 0 2 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 730 0 125 18 0 18 18 0 8 0