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 *425202 37976 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(ffffffff821e8d7c,ffffffff822046f4,2cc,ffffffff8217306b) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802dae97e8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff8255a090) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffe768) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffe768) 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(ffffffff821e8d7c,ffffffff822046f4,2cc,ffffffff8217306b) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802dae97e8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff8255a090) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffe768) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffe768) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff8000148129d0 rbx 0xffff800014812a80 rdx 0x2 rcx 0 rax 0 r8 0xffff800014812990 r9 0x1 r10 0 r11 0x7b0a77f73643fb05 r12 0x3000000008 r13 0xffff8000148129e0 r14 0x100 r15 0x1 rip 0xffffffff81863bd8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000148129c0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=425202 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffffeed0,0xffff8000ffffe500 process=0xffff8000ffffc6c0 user=0xffff80001480d000, vmspace=0xffffffff8255fa48 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 27924 97830 95814 0 3 0x82 piperd syz-executor.0 59737 206084 95814 0 3 0x82 wait syz-executor.1 73761 150188 1 0 3 0x100083 ttyin getty 47414 43607 0 0 3 0x14200 bored sosplice 95814 259407 62680 0 3 0x82 thrsleep syz-fuzzer 95814 187335 62680 0 3 0x4000003 inode syz-fuzzer 95814 189475 62680 0 3 0x4000082 thrsleep syz-fuzzer 95814 376183 62680 0 3 0x4000082 kqread syz-fuzzer 95814 229022 62680 0 2 0x4000003 syz-fuzzer 95814 28855 62680 0 3 0x4000082 thrsleep syz-fuzzer 95814 511715 62680 0 3 0x4000082 thrsleep syz-fuzzer 62680 509982 44923 0 3 0x10008a pause ksh 44923 24726 62499 0 3 0x92 select sshd 62499 404106 1 0 3 0x80 select sshd 45427 336767 75304 73 2 0x100010 syslogd 75304 361821 1 0 3 0x100082 netio syslogd 6434 504243 1 77 3 0x100090 poll dhclient 31502 255856 1 0 3 0x80 poll dhclient 64693 107098 0 0 2 0x14200 zerothread 15566 124202 0 0 3 0x14200 aiodoned aiodoned 58509 55133 0 0 2 0x14200 update 35295 407228 0 0 3 0x14200 cleaner cleaner 47321 364407 0 0 2 0x14200 reaper 53324 156300 0 0 3 0x14200 pgdaemon pagedaemon 86993 234250 0 0 3 0x14200 bored crynlk 1473 373368 0 0 3 0x14200 bored crypto 21884 472368 0 0 3 0x40014200 acpi0 acpi0 81606 304180 0 0 3 0x14200 bored softnet 68278 199897 0 0 2 0x14200 systqmp 60507 4411 0 0 3 0x14200 bored systq *37976 425202 0 0 7 0x40014200 softclock 17245 348884 0 0 3 0x40014200 idle0 11955 472397 0 0 3 0x14200 bored smr 1 392615 0 0 3 0x82 wait init 0 0 -1 0 2 0x10200 swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9540 6369K 7271K 78643K 17199 0 0 pcb 13 13K 14K 78643K 599 0 0 rtable 122 4K 5K 78643K 2028 0 0 ifaddr 75 19K 19K 78643K 589 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 163 0 0 iov 0 0K 32K 78643K 692 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1217 76K 77K 78643K 3707 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 48 0 0 VM map 23 5K 5K 78643K 42 0 0 sem 12 0K 1K 78643K 1605 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 4 9K 25K 78643K 2772 0 0 sigio 0 0K 0K 78643K 61 0 0 proc 49 38K 63K 78643K 1130 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 187 0 0 in_multi 36 2K 2K 78643K 377 0 0 ether_multi 1 0K 0K 78643K 28 0 0 mrt 0 0K 0K 78643K 14 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 78 344K 344K 78643K 78 0 0 exec 0 0K 1K 78643K 685 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 141 188K 188K 78643K 7895 0 0 UVM aobj 130 9K 9K 78643K 169 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 662 0 0 NDP 16 0K 1K 78643K 190 0 0 temp 198 3544K 4183K 78643K 91340 0 0 kqueue 0 0K 0K 78643K 31 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 80 334 0 332 1 0 1 1 0 8 0 rtentry 112 356 0 308 2 0 2 2 0 8 0 unpcb 120 2384 0 2376 5 4 1 2 0 8 0 syncache 264 22 0 22 7 7 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 225 0 225 4 4 0 1 0 8 0 tcpcb 544 4334 0 4330 32 29 3 11 0 8 2 ipq 40 20 0 20 7 7 0 1 0 8 0 ipqe 40 525 0 525 7 7 0 1 0 8 0 inpcb 280 6937 0 6930 36 33 3 13 0 8 2 rttmr 72 6 0 6 4 4 0 1 0 8 0 ip6q 72 1 0 1 1 1 0 1 0 8 0 ip6af 40 3 0 3 1 1 0 1 0 8 0 nd6 48 51 0 47 1 0 1 1 0 8 0 pkpcb 40 18 0 18 6 5 1 1 0 8 1 ppxss 1128 78 0 78 12 11 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1443 0 1211 19 4 15 16 0 8 0 art_table 32 1444 0 1211 2 0 2 2 0 8 0 art_node 16 352 0 309 1 0 1 1 0 8 0 sysvmsgpl 40 29 0 21 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 1603 0 1593 1 0 1 1 0 8 0 shmpl 112 167 0 39 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 5807 0 4401 46 0 46 46 0 8 0 ffsino 240 5807 0 4401 83 0 83 83 0 8 0 nchpl 144 11002 0 10546 61 42 19 61 0 8 0 uvmvnodes 72 6476 0 0 118 0 118 118 0 8 0 vnodes 208 6476 0 0 341 0 341 341 0 8 0 namei 1024 35783 0 35783 1 0 1 1 0 8 1 vcpupl 1984 21 0 0 3 0 3 3 0 8 0 vmpool 520 40 0 19 2 0 2 2 0 8 0 scsiplug 64 4 0 4 4 4 0 1 0 8 0 scxspl 192 34286 0 34286 22 21 1 7 0 8 1 plimitpl 152 230 0 222 1 0 1 1 0 8 0 sigapl 432 2902 0 2890 2 0 2 2 0 8 0 futexpl 56 93453 0 93453 1 0 1 1 0 8 1 knotepl 112 758 0 739 2 1 1 2 0 8 0 kqueuepl 104 1068 0 1066 7 6 1 4 0 8 0 pipepl 112 3204 0 3185 14 13 1 3 0 8 0 fdescpl 424 2903 0 2890 2 0 2 2 0 8 0 filepl 120 30062 0 29967 41 36 5 11 0 8 2 lockfpl 104 991 0 990 1 0 1 1 0 8 0 lockfspl 48 336 0 335 1 0 1 1 0 8 0 sessionpl 112 32 0 22 1 0 1 1 0 8 0 pgrppl 48 62 0 52 1 0 1 1 0 8 0 ucredpl 96 2998 0 2991 1 0 1 1 0 8 0 zombiepl 144 2891 0 2890 1 0 1 1 0 8 0 processpl 864 2919 0 2890 4 0 4 4 0 8 0 procpl 632 6349 0 6314 6 2 4 5 0 8 0 sosppl 128 29 0 29 11 10 1 1 0 8 1 sockpl 384 9709 0 9692 60 55 5 21 0 8 3 mcl64k 65536 1481 0 1481 142 112 30 33 0 8 30 mcl16k 16384 37 0 37 12 12 0 1 0 8 0 mcl12k 12288 77 0 77 11 10 1 1 0 8 1 mcl9k 9216 61 0 61 8 7 1 1 0 8 1 mcl8k 8192 155 0 155 3 2 1 1 0 8 1 mcl4k 4096 317 0 317 3 2 1 1 0 8 1 mcl2k2 2112 16 0 16 6 6 0 1 0 8 0 mcl2k 2048 72626 0 72578 18 11 7 16 0 8 0 mtagpl 80 155 0 136 3 2 1 1 0 8 0 mbufpl 256 159349 0 159225 157 141 16 36 0 8 7 bufpl 256 18767 0 12290 407 2 405 405 0 8 0 anonpl 16 399421 0 375631 158 62 96 96 0 62 0 amapchunkpl 152 15994 0 15597 58 42 16 16 0 158 0 amappl16 192 18165 0 17017 153 86 67 70 0 8 8 amappl15 184 1428 0 1427 1 0 1 1 0 8 0 amappl14 176 556 0 554 1 0 1 1 0 8 0 amappl13 168 363 0 362 2 1 1 1 0 8 0 amappl12 160 191 0 189 2 1 1 1 0 8 0 amappl11 152 526 0 515 1 0 1 1 0 8 0 amappl10 144 122 0 116 1 0 1 1 0 8 0 amappl9 136 762 0 755 1 0 1 1 0 8 0 amappl8 128 332 0 294 3 1 2 2 0 8 0 amappl7 120 184 0 175 1 0 1 1 0 8 0 amappl6 112 515 0 502 1 0 1 1 0 8 0 amappl5 104 464 0 454 1 0 1 1 0 8 0 amappl4 96 3037 0 3008 1 0 1 1 0 8 0 amappl3 88 862 0 850 1 0 1 1 0 8 0 amappl2 80 22662 0 22591 3 1 2 3 0 8 0 amappl1 72 62438 0 62006 27 18 9 20 0 8 0 amappl 80 6861 0 6809 4 2 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 64 168 0 39 3 0 3 3 0 8 0 uaddrrnd 24 2943 0 2890 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2943 0 2890 1 0 1 1 0 8 0 vmmpekpl 168 24399 0 24367 2 0 2 2 0 8 0 vmmpepl 168 361688 0 359383 258 119 139 143 0 357 32 vmsppl 272 2902 0 2889 4 3 1 2 0 8 0 pdppl 4096 5892 0 5837 12 4 8 8 0 8 0 pvpl 32 1034218 0 995595 441 119 322 322 0 265 8 pmappl 200 2942 0 2908 2 0 2 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 899 0 324 17 0 17 17 0 8 0