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 * 93659 75201 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(ffffffff821e484e,ffffffff821fae77,2cc,ffffffff8216bb78) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd8037a69d98) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff824fe1a8) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffe278) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffe278) 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(ffffffff821e484e,ffffffff821fae77,2cc,ffffffff8216bb78) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd8037a69d98) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff824fe1a8) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffe278) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffe278) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014812970 rbx 0xffff800014812a20 rdx 0x2 rcx 0 rax 0 r8 0xffff800014812930 r9 0x1 r10 0 r11 0xe57744d879e819c r12 0x3000000008 r13 0xffff800014812980 r14 0x100 r15 0x1 rip 0xffffffff817d7238 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800014812960 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=93659 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff148,0xffff8000ffffe010 process=0xffff8000ffffc000 user=0xffff80001480d000, vmspace=0xffffffff8256b250 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 32303 265122 83902 0 2 0x2 syz-executor.1 52862 449089 83902 0 3 0x82 wait syz-executor.0 87099 63851 1 0 3 0x100083 ttyopn getty 13202 312326 0 0 3 0x14200 bored sosplice 83902 214973 47773 0 3 0x82 thrsleep syz-fuzzer 83902 310721 47773 0 2 0x4000482 syz-fuzzer 83902 324129 47773 0 3 0x4000082 thrsleep syz-fuzzer 83902 94376 47773 0 3 0x4000082 kqread syz-fuzzer 83902 355991 47773 0 2 0x4000482 syz-fuzzer 83902 286409 47773 0 3 0x4000082 thrsleep syz-fuzzer 83902 443032 47773 0 3 0x4000082 thrsleep syz-fuzzer 47773 68684 30217 0 3 0x10008a pause ksh 30217 422171 37261 0 3 0x92 select sshd 37261 468097 1 0 3 0x80 select sshd 88588 72033 47097 73 2 0x100010 syslogd 47097 424408 1 0 3 0x100082 netio syslogd 5884 432058 1 77 3 0x100090 poll dhclient 88980 315216 1 0 3 0x80 poll dhclient 57937 255283 0 0 2 0x14200 zerothread 95645 162214 0 0 3 0x14200 aiodoned aiodoned 39788 368708 0 0 2 0x14200 update 4997 342677 0 0 3 0x14200 cleaner cleaner 20348 378519 0 0 2 0x14200 reaper 54873 138053 0 0 3 0x14200 pgdaemon pagedaemon 13371 382275 0 0 3 0x14200 bored crynlk 55932 104115 0 0 3 0x14200 bored crypto 94184 503151 0 0 3 0x40014200 acpi0 acpi0 65620 211579 0 0 2 0x14200 softnet 81073 105679 0 0 2 0x14200 systqmp 40728 426567 0 0 3 0x14200 bored systq *75201 93659 0 0 7 0x40014200 softclock 15764 276816 0 0 3 0x40014200 idle0 37652 337626 0 0 3 0x14200 bored smr 1 8183 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 9597 7013K 7913K 78643K 17532 0 0 pcb 13 10K 12K 78643K 820 0 0 rtable 106 8K 8K 78643K 1927 0 0 ifaddr 87 17K 18K 78643K 513 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 183 0 0 iov 0 0K 32K 78643K 666 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1223 77K 77K 78643K 4336 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 38 0 0 VM map 22 5K 5K 78643K 40 0 0 sem 12 1K 1K 78643K 549 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 4 9K 25K 78643K 2859 0 0 sigio 0 0K 0K 78643K 871 0 0 proc 50 38K 55K 78643K 1273 0 0 subproc 32 2K 2K 78643K 311 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 184 0 0 in_multi 24 1K 2K 78643K 342 0 0 ether_multi 1 0K 0K 78643K 36 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 126 556K 556K 78643K 126 0 0 exec 0 0K 1K 78643K 749 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 145 195K 201K 78643K 8037 0 0 UVM aobj 130 4K 4K 78643K 133 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 706 0 0 NDP 21 0K 0K 78643K 161 0 0 temp 233 3541K 4180K 78643K 89637 0 0 kqueue 0 0K 0K 78643K 28 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 80 0 74 1 0 1 1 0 8 0 rtpcb 80 277 0 275 1 0 1 1 0 8 0 rtentry 112 337 0 297 2 0 2 2 0 8 0 unpcb 120 1677 0 1669 2 1 1 2 0 8 0 syncache 264 8 0 8 4 4 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 166 0 166 2 2 0 1 0 8 0 tcpcb 544 1649 0 1645 44 39 5 15 0 8 4 ipq 40 24 0 24 8 8 0 1 0 8 0 ipqe 40 704 0 704 8 8 0 1 0 8 0 inpcb 280 4929 0 4922 28 23 5 9 0 8 4 rttmr 72 1 0 1 1 1 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 39 0 37 2 1 1 1 0 8 0 pkpcb 40 19 0 19 8 8 0 1 0 8 0 ppxss 1128 55 0 55 14 14 0 1 0 8 0 art_heap8 4096 3 0 2 3 2 1 3 0 8 0 art_heap4 256 1291 0 1105 27 15 12 16 0 8 0 art_table 32 1294 0 1107 2 0 2 2 0 8 0 art_node 16 336 0 301 1 0 1 1 0 8 0 sysvmsgpl 40 24 0 16 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 547 0 537 1 0 1 1 0 8 0 shmpl 112 131 0 3 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 6347 0 4940 46 0 46 46 0 8 0 ffsino 240 6347 0 4940 83 0 83 83 0 8 0 nchpl 144 10905 0 9294 61 0 61 61 0 8 0 uvmvnodes 72 5991 0 0 109 0 109 109 0 8 0 vnodes 208 5991 0 0 316 0 316 316 0 8 0 namei 1024 43804 0 43803 2 1 1 1 0 8 0 vcpupl 1984 21 0 1 3 0 3 3 0 8 0 vmpool 520 38 0 18 4 2 2 2 0 8 0 scsiplug 64 1 0 1 1 1 0 1 0 8 0 scxspl 192 34025 0 34025 18 17 1 7 0 8 1 plimitpl 152 245 0 237 1 0 1 1 0 8 0 sigapl 432 2984 0 2972 2 0 2 2 0 8 0 futexpl 56 88375 0 88375 2 2 0 1 0 8 0 knotepl 112 791 0 772 1 0 1 1 0 8 0 kqueuepl 104 1569 0 1567 10 9 1 4 0 8 0 pipepl 112 1918 0 1899 6 5 1 2 0 8 0 fdescpl 424 2985 0 2972 2 0 2 2 0 8 0 filepl 120 32540 0 32445 35 28 7 11 0 8 4 lockfpl 104 1089 0 1088 1 0 1 1 0 8 0 lockfspl 48 380 0 379 1 0 1 1 0 8 0 sessionpl 112 35 0 25 1 0 1 1 0 8 0 pgrppl 48 71 0 61 1 0 1 1 0 8 0 ucredpl 96 9826 0 9818 1 0 1 1 0 8 0 zombiepl 144 2974 0 2973 1 0 1 1 0 8 0 processpl 864 3002 0 2973 4 0 4 4 0 8 0 procpl 632 6472 0 6437 4 0 4 4 0 8 0 sosppl 128 63 0 63 8 8 0 1 0 8 0 sockpl 384 6990 0 6973 46 40 6 14 0 8 4 mcl64k 65536 775 0 775 68 68 0 33 0 8 0 mcl16k 16384 30 0 30 10 10 0 1 0 8 0 mcl12k 12288 104 0 104 8 8 0 1 0 8 0 mcl9k 9216 84 0 84 6 6 0 1 0 8 0 mcl8k 8192 131 0 131 6 6 0 1 0 8 0 mcl4k 4096 317 0 317 4 4 0 1 0 8 0 mcl2k2 2112 18 0 18 9 9 0 1 0 8 0 mcl2k 2048 71658 0 71618 15 9 6 13 0 8 0 mtagpl 80 129 0 125 3 2 1 1 0 8 0 mbufpl 256 141436 0 141357 98 90 8 35 0 8 0 bufpl 256 17910 0 11508 401 0 401 401 0 8 0 anonpl 16 384348 0 362254 177 85 92 97 0 62 3 amapchunkpl 152 15537 0 15140 71 55 16 20 0 158 0 amappl16 192 18152 0 17037 162 101 61 68 0 8 5 amappl15 184 162 0 162 4 4 0 1 0 8 0 amappl14 176 1062 0 1058 1 0 1 1 0 8 0 amappl13 168 386 0 384 1 0 1 1 0 8 0 amappl12 160 233 0 232 5 4 1 1 0 8 0 amappl11 152 482 0 471 1 0 1 1 0 8 0 amappl10 144 183 0 180 1 0 1 1 0 8 0 amappl9 136 1142 0 1134 1 0 1 1 0 8 0 amappl8 128 695 0 657 2 0 2 2 0 8 0 amappl7 120 292 0 284 1 0 1 1 0 8 0 amappl6 112 461 0 444 1 0 1 1 0 8 0 amappl5 104 524 0 514 1 0 1 1 0 8 0 amappl4 96 3027 0 2996 1 0 1 1 0 8 0 amappl3 88 678 0 672 1 0 1 1 0 8 0 amappl2 80 22622 0 22544 3 1 2 3 0 8 0 amappl1 72 64890 0 64459 26 17 9 20 0 8 0 amappl 80 6972 0 6923 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 64 132 0 3 3 0 3 3 0 8 0 uaddrrnd 24 3023 0 2972 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3023 0 2972 1 0 1 1 0 8 0 vmmpekpl 168 21722 0 21692 2 0 2 2 0 8 0 vmmpepl 168 367248 0 364938 260 122 138 141 0 357 32 vmsppl 272 2984 0 2971 2 1 1 2 0 8 0 pdppl 4096 6052 0 5998 11 3 8 8 0 8 0 pvpl 32 954261 0 928556 429 129 300 302 0 265 65 pmappl 200 3022 0 2989 2 0 2 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 779 0 250 16 0 16 16 0 8 0