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 *376738 93275 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(ffffffff821e5ca2,ffffffff821fc336,2cc,ffffffff8216cf7c) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802dddc388) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff824fd3f0) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffec58) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffec58) 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(ffffffff821e5ca2,ffffffff821fc336,2cc,ffffffff8216cf7c) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802dddc388) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff824fd3f0) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffec58) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffec58) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014812950 rbx 0xffff800014812a00 rdx 0x2 rcx 0 rax 0 r8 0xffff800014812910 r9 0x1 r10 0 r11 0x77340fea312d986c r12 0x3000000008 r13 0xffff800014812960 r14 0x100 r15 0x1 rip 0xffffffff8147e928 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800014812940 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=376738 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff148,0xffff8000ffffe778 process=0xffff8000ffffc6c0 user=0xffff80001480d000, vmspace=0xffffffff825a7e20 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 31549 331796 53588 0 2 0x480 syz-executor.1 31549 449737 53588 0 3 0x4000080 ttyout syz-executor.1 31549 383440 53588 0 3 0x4000080 fsleep syz-executor.1 80963 306656 95516 0 3 0x82 piperd syz-executor.0 53588 299332 95516 0 2 0x482 syz-executor.1 15851 226993 1 0 3 0x100083 ttyin getty 62741 19915 0 0 3 0x14200 acct acct 23854 77523 0 0 3 0x14200 bored sosplice 95516 161579 84635 0 3 0x82 thrsleep syz-fuzzer 95516 128678 84635 0 3 0x4000082 thrsleep syz-fuzzer 95516 106782 84635 0 3 0x4000082 kqread syz-fuzzer 95516 88401 84635 0 3 0x4000082 thrsleep syz-fuzzer 95516 133365 84635 0 3 0x4000082 thrsleep syz-fuzzer 95516 411266 84635 0 3 0x4000082 thrsleep syz-fuzzer 95516 111691 84635 0 3 0x4000082 thrsleep syz-fuzzer 95516 313142 84635 0 3 0x4000082 thrsleep syz-fuzzer 84635 176523 61581 0 3 0x10008a pause ksh 61581 441946 70885 0 3 0x92 select sshd 70885 379799 1 0 3 0x80 select sshd 66531 72174 41674 73 3 0x100090 kqread syslogd 41674 189760 1 0 3 0x100082 netio syslogd 48833 44128 1 77 3 0x100090 poll dhclient 56449 522880 1 0 3 0x80 poll dhclient 79254 369780 0 0 3 0x14200 pgzero zerothread 5106 40770 0 0 3 0x14200 aiodoned aiodoned 76380 316106 0 0 3 0x14200 syncer update 65951 108509 0 0 3 0x14200 cleaner cleaner 69373 43356 0 0 3 0x14200 reaper reaper 87492 424906 0 0 3 0x14200 pgdaemon pagedaemon 94324 80342 0 0 3 0x14200 bored crynlk 50189 324406 0 0 3 0x14200 bored crypto 49025 389986 0 0 3 0x40014200 acpi0 acpi0 75387 475747 0 0 3 0x14200 bored softnet 9506 516762 0 0 2 0x14200 systqmp 55401 512235 0 0 3 0x14200 bored systq *93275 376738 0 0 7 0x40014200 softclock 25323 415133 0 0 3 0x40014200 idle0 56188 97070 0 0 3 0x14200 bored smr 1 253324 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 9563 6360K 8609K 78643K 24097 0 0 pcb 13 9K 9K 78643K 485 0 0 rtable 114 12K 14K 78643K 1643 0 0 ifaddr 77 16K 17K 78643K 483 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 153 0 0 iov 0 0K 20K 78643K 584 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1225 77K 77K 78643K 5242 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 51 0 0 VM map 23 5K 5K 78643K 38 0 0 sem 12 0K 0K 78643K 550 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 5 13K 25K 78643K 2377 0 0 sigio 0 0K 0K 78643K 24 0 0 proc 49 38K 55K 78643K 1188 0 0 subproc 32 2K 2K 78643K 238 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 172 0 0 in_multi 26 1K 2K 78643K 229 0 0 ether_multi 1 0K 0K 78643K 18 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 138 609K 609K 78643K 138 0 0 exec 0 0K 1K 78643K 653 0 0 pfkey data 0 0K 0K 78643K 2 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 143 169K 171K 78643K 6803 0 0 UVM aobj 130 6K 6K 78643K 172 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 1K 78643K 492 0 0 NDP 18 0K 0K 78643K 150 0 0 temp 212 3540K 4180K 78643K 66377 0 0 kqueue 0 0K 0K 78643K 33 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 57 0 50 1 0 1 1 0 8 0 rtpcb 80 319 0 317 1 0 1 1 0 8 0 rtentry 112 251 0 210 2 0 2 2 0 8 0 unpcb 120 1609 0 1593 2 1 1 2 0 8 0 syncache 264 17 0 17 6 6 0 1 0 8 0 tcpqe 32 215 0 215 3 3 0 1 0 8 0 tcpcb 544 815 0 811 3 2 1 2 0 8 0 ipq 40 18 0 18 7 7 0 1 0 8 0 ipqe 40 432 0 432 7 7 0 1 0 8 0 inpcb 280 2780 0 2773 12 10 2 4 0 8 1 rttmr 72 3 0 3 3 3 0 1 0 8 0 nd6 48 28 0 26 5 4 1 1 0 8 0 pkpcb 40 6 0 6 4 4 0 1 0 8 0 swfcl 56 2 0 0 1 0 1 1 0 8 0 ppxss 1128 61 0 61 9 8 1 1 0 8 1 art_heap8 4096 9 0 8 7 6 1 3 0 8 0 art_heap4 256 1058 0 858 30 16 14 16 0 8 0 art_table 32 1067 0 866 2 0 2 2 0 8 0 art_node 16 250 0 210 1 0 1 1 0 8 0 sysvmsgpl 40 50 0 24 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 548 0 538 1 0 1 1 0 8 0 shmpl 112 170 0 42 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 5231 0 3834 46 0 46 46 0 8 0 ffsino 240 5231 0 3834 83 0 83 83 0 8 0 nchpl 144 9104 0 8646 61 41 20 61 0 8 0 uvmvnodes 72 6162 0 0 113 0 113 113 0 8 0 vnodes 208 6162 0 0 325 0 325 325 0 8 0 namei 1024 31629 0 31629 2 1 1 1 0 8 1 vcpupl 1984 21 0 0 3 0 3 3 0 8 0 vmpool 520 36 0 15 3 1 2 2 0 8 0 scsiplug 64 2 0 2 1 1 0 1 0 8 0 scxspl 192 34974 0 34974 25 24 1 7 0 8 1 plimitpl 152 213 0 205 1 0 1 1 0 8 0 sigapl 432 2514 0 2501 2 0 2 2 0 8 0 futexpl 56 73548 0 73547 2 1 1 1 0 8 0 knotepl 112 1388 0 1369 3 2 1 2 0 8 0 kqueuepl 104 1749 0 1747 1 0 1 1 0 8 0 pipepl 112 5910 0 5891 9 7 2 3 0 8 1 fdescpl 424 2515 0 2501 2 0 2 2 0 8 0 filepl 120 27169 0 27071 18 12 6 7 0 8 2 lockfpl 104 897 0 896 1 0 1 1 0 8 0 lockfspl 48 312 0 311 1 0 1 1 0 8 0 sessionpl 112 31 0 21 1 0 1 1 0 8 0 pgrppl 48 67 0 57 1 0 1 1 0 8 0 ucredpl 96 2905 0 2898 1 0 1 1 0 8 0 zombiepl 144 2501 0 2501 1 0 1 1 0 8 1 processpl 864 2531 0 2501 4 0 4 4 0 8 0 procpl 632 5429 0 5390 4 0 4 4 0 8 0 sosppl 128 41 0 41 8 8 0 1 0 8 0 sockpl 384 4742 0 4717 18 14 4 7 0 8 1 mcl64k 65536 233 0 233 4 3 1 1 0 8 1 mcl16k 16384 22 0 22 9 9 0 1 0 8 0 mcl12k 12288 56 0 56 7 6 1 1 0 8 1 mcl9k 9216 45 0 45 13 12 1 1 0 8 1 mcl8k 8192 119 0 119 6 5 1 1 0 8 1 mcl4k 4096 297 0 297 4 3 1 1 0 8 1 mcl2k2 2112 33 0 33 9 9 0 1 0 8 0 mcl2k 2048 71187 0 71146 13 7 6 12 0 8 0 mtagpl 80 96 0 96 2 1 1 1 0 8 1 mbufpl 256 139702 0 139600 96 85 11 39 0 8 0 bufpl 256 17322 0 11160 386 0 386 386 0 8 0 anonpl 16 316255 0 297696 172 74 98 104 0 62 16 amapchunkpl 152 12669 0 12538 57 40 17 20 0 158 10 amappl16 192 15278 0 14146 152 84 68 71 0 8 10 amappl15 184 444 0 443 1 0 1 1 0 8 0 amappl14 176 637 0 633 1 0 1 1 0 8 0 amappl13 168 1058 0 1058 1 0 1 1 0 8 1 amappl12 160 43 0 40 1 0 1 1 0 8 0 amappl11 152 78 0 67 1 0 1 1 0 8 0 amappl10 144 159 0 154 1 0 1 1 0 8 0 amappl9 136 745 0 738 1 0 1 1 0 8 0 amappl8 128 318 0 284 2 0 2 2 0 8 0 amappl7 120 224 0 216 1 0 1 1 0 8 0 amappl6 112 87 0 78 1 0 1 1 0 8 0 amappl5 104 274 0 264 1 0 1 1 0 8 0 amappl4 96 2693 0 2666 1 0 1 1 0 8 0 amappl3 88 1003 0 998 1 0 1 1 0 8 0 amappl2 80 19681 0 19610 3 1 2 3 0 8 0 amappl1 72 55009 0 54591 26 17 9 20 0 8 0 amappl 80 5883 0 5834 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 64 171 0 42 3 0 3 3 0 8 0 uaddrrnd 24 2551 0 2501 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2551 0 2501 1 0 1 1 0 8 0 vmmpekpl 168 27544 0 27509 2 0 2 2 0 8 0 vmmpepl 168 314375 0 312076 284 142 142 142 0 357 36 vmsppl 272 2514 0 2501 3 1 2 2 0 8 1 pdppl 4096 5108 0 5053 10 2 8 8 0 8 0 pvpl 32 841319 0 820653 440 136 304 322 0 265 120 pmappl 200 2550 0 2516 2 0 2 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 661 0 142 16 1 15 16 0 8 0