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 *300112 36761 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(fffffd802b5f0548) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff8255a090) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffeed0) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffeed0) 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(fffffd802b5f0548) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff8255a090) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffeed0) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffeed0) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014812400 rbx 0xffff8000148124b0 rdx 0x2 rcx 0 rax 0 r8 0xffff8000148123c0 r9 0x1 r10 0 r11 0xb096843c836670af r12 0x3000000008 r13 0xffff800014812410 r14 0x100 r15 0x1 rip 0xffffffff81863bd8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000148123f0 ss 0 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=300112 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff148,0xffff8000ffffe778 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 93428 498387 94746 0 2 0 syz-executor.1 93428 184486 94746 0 3 0x4000080 piperd syz-executor.1 93428 497908 94746 0 3 0x4000080 piperd syz-executor.1 93428 499663 94746 0 2 0x4000000 syz-executor.1 94961 328158 64529 0 2 0x480 syz-executor.0 94961 71676 64529 0 3 0x4000080 ttyout syz-executor.0 94961 384351 64529 0 3 0x4000080 fsleep syz-executor.0 94746 258862 92494 0 2 0x482 syz-executor.1 64529 39405 92494 0 2 0x482 syz-executor.0 66315 396534 1 0 3 0x100083 ttyopn getty 57468 12785 0 0 3 0x14200 bored sosplice 92494 151168 9339 0 3 0x82 thrsleep syz-fuzzer 92494 242104 9339 0 3 0x4000082 thrsleep syz-fuzzer 92494 350527 9339 0 3 0x4000082 thrsleep syz-fuzzer 92494 149791 9339 0 3 0x4000082 thrsleep syz-fuzzer 92494 24996 9339 0 3 0x4000082 thrsleep syz-fuzzer 92494 207289 9339 0 3 0x4000082 kqread syz-fuzzer 92494 195553 9339 0 3 0x4000082 thrsleep syz-fuzzer 9339 440171 50578 0 3 0x10008a pause ksh 50578 412524 64260 0 3 0x92 select sshd 64260 473690 1 0 3 0x80 select sshd 36160 30627 97729 73 3 0x100090 kqread syslogd 97729 326462 1 0 3 0x100082 netio syslogd 36710 232550 1 77 3 0x100090 poll dhclient 12051 399933 1 0 3 0x80 poll dhclient 31801 378806 0 0 2 0x14200 zerothread 11144 270852 0 0 3 0x14200 aiodoned aiodoned 28340 256388 0 0 3 0x14200 syncer update 53976 161095 0 0 3 0x14200 cleaner cleaner 99938 248711 0 0 3 0x14200 reaper reaper 11710 481451 0 0 3 0x14200 pgdaemon pagedaemon 34316 72288 0 0 3 0x14200 bored crynlk 75066 250648 0 0 3 0x14200 bored crypto 46060 40942 0 0 3 0x40014200 acpi0 acpi0 42220 230620 0 0 3 0x14200 bored softnet 60602 317302 0 0 2 0x14200 systqmp 32094 248755 0 0 3 0x14200 bored systq *36761 300112 0 0 7 0x40014200 softclock 82942 347408 0 0 3 0x40014200 idle0 81625 523894 0 0 3 0x14200 bored smr 1 490913 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 9582 6382K 7407K 78643K 20135 0 0 pcb 14 11K 12K 78643K 803 0 0 rtable 101 8K 9K 78643K 2585 0 0 ifaddr 85 19K 21K 78643K 733 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 341 0 0 iov 0 0K 24K 78643K 992 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1224 77K 78K 78643K 5864 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 69 0 0 VM map 41 10K 10K 78643K 72 0 0 sem 12 0K 1K 78643K 1539 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 6 17K 25K 78643K 3996 0 0 sigio 0 0K 0K 78643K 49 0 0 proc 49 38K 63K 78643K 1500 0 0 subproc 32 2K 2K 78643K 340 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 1908 0 0 in_multi 16 1K 2K 78643K 366 0 0 ether_multi 1 0K 0K 78643K 22 0 0 mrt 0 0K 0K 78643K 15 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 138 609K 609K 78643K 138 0 0 exec 0 0K 1K 78643K 898 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 176 348K 364K 78643K 11964 0 0 UVM aobj 130 4K 4K 78643K 136 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 2 0K 0K 78643K 861 0 0 NDP 20 0K 0K 78643K 234 0 0 temp 226 3544K 4184K 78643K 184314 0 0 kqueue 0 0K 0K 78643K 35 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 84 0 78 1 0 1 1 0 8 0 rtpcb 80 526 0 524 1 0 1 1 0 8 0 rtentry 112 422 0 388 2 0 2 2 0 8 0 unpcb 120 1982 0 1968 2 1 1 2 0 8 0 syncache 264 30 0 30 14 14 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 89 0 89 8 8 0 1 0 8 0 tcpcb 544 3492 0 3488 44 43 1 14 0 8 0 ipq 40 32 0 32 13 12 1 1 0 8 1 ipqe 40 373 0 373 13 12 1 1 0 8 1 inpcb 280 6407 0 6399 36 34 2 9 0 8 1 rttmr 72 7 0 6 2 1 1 1 0 8 0 ip6q 72 5 0 5 3 3 0 1 0 8 0 ip6af 40 10 0 10 2 2 0 1 0 8 0 nd6 48 51 0 51 1 1 0 1 0 8 0 pkpcb 40 11 0 11 6 6 0 1 0 8 0 swfcl 56 4 0 0 1 0 1 1 0 8 0 ppxss 1128 86 0 86 24 23 1 1 0 8 1 art_heap8 4096 12 0 10 8 5 3 4 0 8 1 art_heap4 256 1707 0 1530 24 9 15 17 0 8 0 art_table 32 1719 0 1540 4 1 3 3 0 8 0 art_node 16 421 0 389 1 0 1 1 0 8 0 sysvmsgpl 40 69 0 53 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 1535 0 1525 1 0 1 1 0 8 0 shmpl 112 134 0 6 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 8790 0 7390 46 0 46 46 0 8 0 ffsino 240 8790 0 7390 83 0 83 83 0 8 0 nchpl 144 15813 0 15338 60 41 19 60 0 8 0 uvmvnodes 72 6541 0 0 119 0 119 119 0 8 0 vnodes 208 6541 0 0 345 0 345 345 0 8 0 namei 1024 62931 0 62931 1 0 1 1 0 8 1 vcpupl 1984 40 0 1 5 0 5 5 0 8 0 vmpool 520 70 0 31 3 0 3 3 0 8 0 scsiplug 64 3 0 3 2 2 0 1 0 8 0 scxspl 192 49080 0 49080 30 29 1 7 0 8 1 plimitpl 152 350 0 343 1 0 1 1 0 8 0 sigapl 432 4114 0 4100 2 0 2 2 0 8 0 futexpl 56 120367 0 120366 1 0 1 1 0 8 0 knotepl 112 1207 0 1188 5 4 1 3 0 8 0 kqueuepl 104 1556 0 1554 10 9 1 4 0 8 0 pipepl 112 2506 0 2485 10 9 1 2 0 8 0 fdescpl 424 4115 0 4100 2 0 2 2 0 8 0 filepl 120 44636 0 44533 41 37 4 11 0 8 0 lockfpl 104 1770 0 1768 1 0 1 1 0 8 0 lockfspl 48 506 0 504 1 0 1 1 0 8 0 sessionpl 112 36 0 26 1 0 1 1 0 8 0 pgrppl 48 109 0 99 1 0 1 1 0 8 0 ucredpl 96 14377 0 14368 1 0 1 1 0 8 0 zombiepl 144 4102 0 4102 1 0 1 1 0 8 1 processpl 864 4132 0 4102 4 0 4 4 0 8 0 procpl 632 10179 0 10138 5 1 4 5 0 8 0 sosppl 128 70 0 70 19 18 1 1 0 8 1 sockpl 384 8994 0 8970 63 59 4 14 0 8 1 mcl64k 65536 1203 0 1203 79 78 1 33 0 8 1 mcl16k 16384 61 0 61 22 22 0 1 0 8 0 mcl12k 12288 123 0 123 28 27 1 1 0 8 1 mcl9k 9216 73 0 73 24 24 0 1 0 8 0 mcl8k 8192 174 0 174 16 15 1 1 0 8 1 mcl4k 4096 439 0 439 5 4 1 1 0 8 1 mcl2k2 2112 36 0 36 19 19 0 1 0 8 0 mcl2k 2048 72783 0 72733 24 17 7 14 0 8 0 mtagpl 80 210 0 210 6 5 1 1 0 8 1 mbufpl 256 154246 0 154166 140 129 11 39 0 8 0 bufpl 256 22980 0 16373 414 0 414 414 0 8 0 anonpl 16 542544 0 523443 272 178 94 95 0 62 15 amapchunkpl 152 24406 0 24268 105 94 11 20 0 158 4 amappl16 192 27234 0 26122 307 243 64 69 0 8 8 amappl15 184 1216 0 1214 3 2 1 1 0 8 0 amappl14 176 1953 0 1944 1 0 1 1 0 8 0 amappl13 168 150 0 150 4 4 0 1 0 8 0 amappl12 160 131 0 130 1 0 1 1 0 8 0 amappl11 152 272 0 260 1 0 1 1 0 8 0 amappl10 144 181 0 175 1 0 1 1 0 8 0 amappl9 136 821 0 815 1 0 1 1 0 8 0 amappl8 128 380 0 340 2 0 2 2 0 8 0 amappl7 120 298 0 292 1 0 1 1 0 8 0 amappl6 112 274 0 261 1 0 1 1 0 8 0 amappl5 104 437 0 427 1 0 1 1 0 8 0 amappl4 96 4035 0 4010 1 0 1 1 0 8 0 amappl3 88 1962 0 1950 1 0 1 1 0 8 0 amappl2 80 32119 0 32038 3 1 2 3 0 8 0 amappl1 72 87520 0 87082 26 16 10 20 0 8 0 amappl 80 10748 0 10686 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 64 135 0 6 3 0 3 3 0 8 0 uaddrrnd 24 4185 0 4100 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4185 0 4100 1 0 1 1 0 8 0 vmmpekpl 168 30672 0 30637 2 0 2 2 0 8 0 vmmpepl 168 513112 0 510709 432 317 115 145 0 357 10 vmsppl 272 4114 0 4100 4 3 1 2 0 8 0 pdppl 4096 8376 0 8301 11 1 10 10 0 8 0 pvpl 32 1360340 0 1338325 553 337 216 282 0 265 36 pmappl 200 4184 0 4131 4 1 3 3 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 880 0 328 16 0 16 16 0 8 0