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 *338793 45043 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(ffffffff821e4d3c,ffffffff82200582,2cc,ffffffff8216c2d5) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802c1e9388) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff82557af8) 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(ffffffff821e4d3c,ffffffff82200582,2cc,ffffffff8216c2d5) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802c1e9388) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff82557af8) 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 0xffff8000148125c0 rbx 0xffff800014812670 rdx 0x2 rcx 0 rax 0 r8 0xffff800014812580 r9 0x1 r10 0 r11 0x2fe15488fa8e9f7 r12 0x3000000008 r13 0xffff8000148125d0 r14 0x100 r15 0x1 rip 0xffffffff815c9928 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000148125b0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=338793 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffffe9e0,0xffff8000ffffe010 process=0xffff8000ffffc6c0 user=0xffff80001480d000, vmspace=0xffffffff82559538 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 36708 182956 11586 0 3 0x82 piperd syz-executor.1 45230 449165 0 0 3 0x14200 acct acct 60019 194302 1 0 3 0x100083 ttyin getty 76631 342830 0 0 3 0x14200 bored sosplice 11586 56618 41724 0 3 0x82 thrsleep syz-fuzzer 11586 408231 41724 0 3 0x4000082 thrsleep syz-fuzzer 11586 426952 41724 0 3 0x4000082 thrsleep syz-fuzzer 11586 189490 41724 0 3 0x4000082 thrsleep syz-fuzzer 11586 120037 41724 0 3 0x4000082 thrsleep syz-fuzzer 11586 343469 41724 0 3 0x4000082 kqread syz-fuzzer 11586 317332 41724 0 3 0x4000082 thrsleep syz-fuzzer 11586 319845 41724 0 3 0x4000082 thrsleep syz-fuzzer 41724 288126 96653 0 3 0x10008a pause ksh 96653 399142 14417 0 3 0x92 select sshd 14417 108843 1 0 3 0x80 select sshd 11701 163606 53530 73 3 0x100090 kqread syslogd 53530 32946 1 0 3 0x100082 netio syslogd 50906 198545 1 77 3 0x100090 poll dhclient 50858 408644 1 0 3 0x80 poll dhclient 95595 6851 0 0 3 0x14200 pgzero zerothread 5027 96148 0 0 3 0x14200 aiodoned aiodoned 17841 221095 0 0 3 0x14200 syncer update 72099 245858 0 0 3 0x14200 cleaner cleaner 67557 210352 0 0 3 0x14200 reaper reaper 65698 73476 0 0 3 0x14200 pgdaemon pagedaemon 29256 114647 0 0 3 0x14200 bored crynlk 25594 341155 0 0 3 0x14200 bored crypto 19054 121483 0 0 3 0x40014200 acpi0 acpi0 86971 136563 0 0 3 0x14200 bored softnet 21547 121491 0 0 3 0x14200 bored systqmp 58106 379214 0 0 3 0x14200 bored systq *45043 338793 0 0 7 0x40014200 softclock 25065 489243 0 0 3 0x40014200 idle0 45454 45860 0 0 3 0x14200 bored smr 1 388034 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 9545 6357K 7738K 78643K 15052 0 0 pcb 13 8K 9K 78643K 378 0 0 rtable 103 5K 6K 78643K 1107 0 0 ifaddr 75 16K 17K 78643K 325 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 300 0 0 iov 0 0K 24K 78643K 365 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1219 77K 77K 78643K 3044 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 31 0 0 VM map 16 4K 4K 78643K 28 0 0 sem 12 0K 1K 78643K 1109 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 3 5K 25K 78643K 2936 0 0 sigio 0 0K 0K 78643K 22 0 0 proc 50 38K 55K 78643K 908 0 0 subproc 16 1K 2K 78643K 187 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 148 0 0 in_multi 23 1K 2K 78643K 149 0 0 ether_multi 1 0K 0K 78643K 18 0 0 mrt 1 0K 0K 78643K 21 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 454 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 118 127K 144K 78643K 8324 0 0 UVM aobj 130 7K 7K 78643K 137 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 374 0 0 NDP 17 0K 0K 78643K 94 0 0 temp 190 3539K 4171K 78643K 44207 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 37 0 31 1 0 1 1 0 8 0 rtpcb 80 177 0 175 1 0 1 1 0 8 0 rtentry 112 182 0 145 2 0 2 2 0 8 0 unpcb 120 843 0 831 2 1 1 2 0 8 0 syncache 264 15 0 15 6 6 0 1 0 8 0 tcpqe 32 136 0 136 4 4 0 1 0 8 0 tcpcb 544 1088 0 1084 4 3 1 2 0 8 0 ipq 40 4 0 4 4 4 0 1 0 8 0 ipqe 40 96 0 96 4 4 0 1 0 8 0 inpcb 280 3109 0 3102 28 27 1 4 0 8 0 rttmr 72 7 0 7 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 16 0 14 2 1 1 1 0 8 0 pkpcb 40 9 0 9 4 4 0 1 0 8 0 ppxss 1128 36 0 36 18 18 0 1 0 8 0 art_heap8 4096 6 0 5 4 3 1 3 0 8 0 art_heap4 256 658 0 482 17 5 12 14 0 8 1 art_table 32 664 0 487 2 0 2 2 0 8 0 art_node 16 176 0 142 1 0 1 1 0 8 0 sysvmsgpl 40 13 0 8 1 0 1 1 0 8 0 semupl 112 3 0 3 2 2 0 1 0 8 0 semapl 112 1107 0 1097 1 0 1 1 0 8 0 shmpl 112 135 0 7 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 5730 0 4336 46 0 46 46 0 8 0 ffsino 240 5730 0 4336 83 0 83 83 0 8 0 nchpl 144 10091 0 9655 61 41 20 61 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 208 5926 0 0 312 0 312 312 0 8 0 namei 1024 31073 0 31073 1 0 1 1 0 8 1 vcpupl 1984 14 0 0 2 0 2 2 0 8 0 vmpool 520 26 0 12 3 2 1 2 0 8 0 scsiplug 64 4 0 4 3 3 0 1 0 8 0 scxspl 192 30146 0 30146 17 16 1 7 0 8 1 plimitpl 152 121 0 115 1 0 1 1 0 8 0 sigapl 432 3081 0 3070 2 0 2 2 0 8 0 futexpl 56 60411 0 60411 1 0 1 1 0 8 1 knotepl 112 622 0 609 1 0 1 1 0 8 0 kqueuepl 104 2058 0 2056 1 0 1 1 0 8 0 pipepl 112 2498 0 2485 4 3 1 2 0 8 0 fdescpl 424 3082 0 3070 2 0 2 2 0 8 0 filepl 120 21616 0 21544 11 7 4 6 0 8 1 lockfpl 104 470 0 469 1 0 1 1 0 8 0 lockfspl 48 168 0 167 1 0 1 1 0 8 0 sessionpl 112 27 0 18 1 0 1 1 0 8 0 pgrppl 48 45 0 36 1 0 1 1 0 8 0 ucredpl 96 3691 0 3684 1 0 1 1 0 8 0 zombiepl 144 3072 0 3072 1 0 1 1 0 8 1 processpl 864 3100 0 3072 4 0 4 4 0 8 0 procpl 632 6857 0 6822 4 0 4 4 0 8 0 sosppl 128 33 0 33 13 13 0 1 0 8 0 sockpl 384 4153 0 4132 36 33 3 7 0 8 0 mcl64k 65536 885 0 885 90 90 0 32 0 8 0 mcl16k 16384 21 0 21 16 16 0 1 0 8 0 mcl12k 12288 360 0 360 25 25 0 1 0 8 0 mcl9k 9216 33 0 33 20 20 0 1 0 8 0 mcl8k 8192 74 0 74 33 33 0 1 0 8 0 mcl4k 4096 381 0 381 32 31 1 1 0 8 1 mcl2k2 2112 28 0 28 14 14 0 1 0 8 0 mcl2k 2048 72538 0 72496 32 26 6 13 0 8 0 mtagpl 80 65 0 65 5 5 0 1 0 8 0 mbufpl 256 138794 0 138722 97 89 8 38 0 8 0 bufpl 256 12018 0 7018 313 0 313 313 0 8 0 anonpl 16 1820842 0 1806871 305 198 107 111 0 62 15 amapchunkpl 152 20976 0 20872 79 69 10 20 0 158 5 amappl16 192 106091 0 105015 803 739 64 79 0 8 8 amappl15 184 1071 0 1071 2 1 1 1 0 8 1 amappl14 176 179 0 175 1 0 1 1 0 8 0 amappl13 168 9 0 8 2 1 1 1 0 8 0 amappl12 160 11 0 9 1 0 1 1 0 8 0 amappl11 152 60 0 49 1 0 1 1 0 8 0 amappl10 144 18 0 16 1 0 1 1 0 8 0 amappl9 136 668 0 662 1 0 1 1 0 8 0 amappl8 128 237 0 208 2 0 2 2 0 8 1 amappl7 120 80 0 73 1 0 1 1 0 8 0 amappl6 112 86 0 78 1 0 1 1 0 8 0 amappl5 104 199 0 189 1 0 1 1 0 8 0 amappl4 96 3126 0 3098 1 0 1 1 0 8 0 amappl3 88 641 0 633 1 0 1 1 0 8 0 amappl2 80 22710 0 22652 3 1 2 3 0 8 0 amappl1 72 62665 0 62285 27 18 9 20 0 8 0 amappl 80 7626 0 7586 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 64 136 0 7 3 0 3 3 0 8 0 uaddrrnd 24 3108 0 3070 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3108 0 3070 1 0 1 1 0 8 0 vmmpekpl 168 22567 0 22544 2 0 2 2 0 8 0 vmmpepl 168 451546 0 449563 378 226 152 152 0 357 50 vmsppl 272 3081 0 3070 3 1 2 2 0 8 1 pdppl 4096 6222 0 6178 10 3 7 7 0 8 0 pvpl 32 2535851 0 2518974 614 355 259 264 0 265 60 pmappl 200 3107 0 3082 2 0 2 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 740 0 302 14 0 14 14 0 8 0