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 * 24997 42617 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(fffffd80352ab0e8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff82557af8) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000fffff3c0) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000fffff3c0) 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(fffffd80352ab0e8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff82557af8) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000fffff3c0) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000fffff3c0) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014811da0 rbx 0xffff800014811e50 rdx 0x2 rcx 0 rax 0 r8 0xffff800014811d60 r9 0x1 r10 0 r11 0xba77eae4f810609d r12 0x3000000008 r13 0xffff800014811db0 r14 0x100 r15 0x1 rip 0xffffffff815c9928 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800014811d90 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=24997 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff638,0xffff8000ffffeee0 process=0xffff8000ffffc000 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 12690 495438 73321 0 2 0 syz-executor.1 12690 63765 73321 0 3 0x4000080 fsleep syz-executor.1 99111 432227 39256 0 2 0 syz-executor.0 99111 101011 39256 0 3 0x4000080 ttyopn syz-executor.0 99111 92948 39256 0 2 0x4000000 syz-executor.0 39256 132369 91113 0 2 0x482 syz-executor.0 73321 146789 91113 0 2 0x482 syz-executor.1 97127 170810 0 0 3 0x14200 bored sosplice 91113 221650 93775 0 3 0x82 thrsleep syz-fuzzer 91113 224768 93775 0 3 0x4000082 thrsleep syz-fuzzer 91113 77564 93775 0 3 0x4000082 thrsleep syz-fuzzer 91113 432781 93775 0 3 0x4000082 thrsleep syz-fuzzer 91113 268565 93775 0 3 0x4000082 kqread syz-fuzzer 91113 162346 93775 0 3 0x4000082 thrsleep syz-fuzzer 91113 130622 93775 0 3 0x4000082 thrsleep syz-fuzzer 91113 450290 93775 0 3 0x4000082 thrsleep syz-fuzzer 93775 516781 30725 0 3 0x10008a pause ksh 30725 494608 19857 0 3 0x92 select sshd 26702 305894 1 0 3 0x100083 ttyin getty 19857 297359 1 0 3 0x80 select sshd 57409 353485 5582 73 3 0x100090 kqread syslogd 5582 475176 1 0 3 0x100082 netio syslogd 76243 8744 1 77 3 0x100090 poll dhclient 10272 496243 1 0 3 0x80 poll dhclient 16210 62876 0 0 2 0x14200 zerothread 13154 426954 0 0 3 0x14200 aiodoned aiodoned 15179 122818 0 0 3 0x14200 syncer update 43962 82421 0 0 3 0x14200 cleaner cleaner 34904 428142 0 0 3 0x14200 reaper reaper 73370 251329 0 0 3 0x14200 pgdaemon pagedaemon 32879 225377 0 0 3 0x14200 bored crynlk 89602 120728 0 0 3 0x14200 bored crypto 80324 125157 0 0 3 0x40014200 acpi0 acpi0 59466 497935 0 0 3 0x14200 bored softnet 52848 120339 0 0 3 0x14200 bored systqmp 77034 268741 0 0 3 0x14200 bored systq *42617 24997 0 0 7 0x40014200 softclock 95979 199525 0 0 3 0x40014200 idle0 70029 209048 0 0 3 0x14200 bored smr 1 216166 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 9584 6387K 9206K 78643K 24446 0 0 pcb 13 10K 12K 78643K 859 0 0 rtable 111 12K 13K 78643K 1680 0 0 ifaddr 90 18K 19K 78643K 447 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 120 0 0 iov 0 0K 32K 78643K 588 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1234 77K 78K 78643K 5133 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 53 0 0 VM map 20 5K 5K 78643K 32 0 0 sem 12 0K 0K 78643K 477 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 6 17K 25K 78643K 2435 0 0 sigio 0 0K 0K 78643K 18 0 0 proc 49 38K 62K 78643K 1130 0 0 subproc 32 2K 2K 78643K 310 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 559 0 0 in_multi 21 1K 2K 78643K 306 0 0 ether_multi 1 0K 0K 78643K 18 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 78 344K 344K 78643K 78 0 0 exec 0 0K 1K 78643K 654 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 137 185K 201K 78643K 6995 0 0 UVM aobj 130 6K 6K 78643K 141 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 438 0 0 NDP 22 0K 0K 78643K 146 0 0 temp 243 3541K 3616K 78643K 84146 0 0 kqueue 0 0K 0K 78643K 9 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 58 1 0 1 1 0 8 0 rtpcb 80 371 0 369 1 0 1 1 0 8 0 rtentry 112 299 0 261 2 0 2 2 0 8 0 unpcb 120 1002 0 993 1 0 1 1 0 8 0 syncache 264 14 0 14 7 7 0 1 0 8 0 tcpqe 32 3 0 3 3 3 0 1 0 8 0 tcpcb 544 1190 0 1186 8 7 1 2 0 8 0 ipq 40 11 0 11 5 4 1 1 0 8 1 ipqe 40 114 0 114 5 4 1 1 0 8 1 inpcb 280 3657 0 3647 24 22 2 13 0 8 0 rttmr 72 2 0 2 2 2 0 1 0 8 0 nd6 48 42 0 41 2 1 1 1 0 8 0 pkpcb 40 16 0 16 5 4 1 1 0 8 1 swfcl 56 2 0 0 1 0 1 1 0 8 0 ppxss 1128 40 0 40 9 9 0 1 0 8 0 art_heap8 4096 9 0 8 4 3 1 3 0 8 0 art_heap4 256 1249 0 1067 23 10 13 16 0 8 0 art_table 32 1258 0 1075 2 0 2 2 0 8 0 art_node 16 298 0 262 1 0 1 1 0 8 0 sysvmsgpl 40 78 0 59 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 475 0 465 1 0 1 1 0 8 0 shmpl 112 139 0 11 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 5035 0 3636 46 0 46 46 0 8 0 ffsino 240 5035 0 3636 83 0 83 83 0 8 0 nchpl 144 9246 0 7637 60 0 60 60 0 8 0 uvmvnodes 72 6423 0 0 117 0 117 117 0 8 0 vnodes 208 6423 0 0 339 0 339 339 0 8 0 namei 1024 31819 0 31819 2 1 1 1 0 8 1 vcpupl 1984 19 0 1 3 0 3 3 0 8 0 vmpool 520 30 0 12 2 0 2 2 0 8 0 scsiplug 64 2 0 2 2 1 1 1 0 8 1 scxspl 192 33354 0 33354 20 19 1 7 0 8 1 plimitpl 152 257 0 250 1 0 1 1 0 8 0 sigapl 432 2558 0 2544 2 0 2 2 0 8 0 futexpl 56 70323 0 70322 3 2 1 1 0 8 0 knotepl 112 648 0 629 1 0 1 1 0 8 0 kqueuepl 104 578 0 576 1 0 1 1 0 8 0 pipepl 112 1460 0 1441 4 3 1 2 0 8 0 fdescpl 424 2559 0 2544 2 0 2 2 0 8 0 filepl 120 22661 0 22563 20 16 4 11 0 8 1 lockfpl 104 890 0 889 1 0 1 1 0 8 0 lockfspl 48 292 0 291 1 0 1 1 0 8 0 sessionpl 112 33 0 23 1 0 1 1 0 8 0 pgrppl 48 53 0 43 1 0 1 1 0 8 0 ucredpl 96 2964 0 2957 1 0 1 1 0 8 0 zombiepl 144 2548 0 2548 1 0 1 1 0 8 1 processpl 864 2578 0 2548 4 0 4 4 0 8 0 procpl 632 5412 0 5372 4 0 4 4 0 8 0 sosppl 128 14 0 14 6 5 1 1 0 8 1 sockpl 384 5081 0 5062 38 34 4 21 0 8 1 mcl64k 65536 430 0 430 33 32 1 29 0 8 1 mcl16k 16384 22 0 22 8 7 1 1 0 8 1 mcl12k 12288 67 0 67 8 7 1 1 0 8 1 mcl9k 9216 40 0 40 7 6 1 1 0 8 1 mcl8k 8192 115 0 115 6 5 1 1 0 8 1 mcl4k 4096 387 0 386 5 4 1 1 0 8 0 mcl2k2 2112 23 0 23 8 8 0 1 0 8 0 mcl2k 2048 70682 0 70638 18 11 7 13 0 8 0 mtagpl 80 112 0 104 2 1 1 1 0 8 0 mbufpl 256 133635 0 133506 62 45 17 29 0 8 0 bufpl 256 15555 0 9132 402 0 402 402 0 8 0 anonpl 16 367313 0 347775 161 66 95 95 0 62 11 amapchunkpl 152 14133 0 13999 49 40 9 19 0 158 3 amappl16 192 16796 0 15632 170 102 68 71 0 8 8 amappl15 184 738 0 734 3 2 1 1 0 8 0 amappl14 176 514 0 507 1 0 1 1 0 8 0 amappl13 168 473 0 473 3 3 0 1 0 8 0 amappl12 160 52 0 47 1 0 1 1 0 8 0 amappl11 152 192 0 181 1 0 1 1 0 8 0 amappl10 144 554 0 553 1 0 1 1 0 8 0 amappl9 136 976 0 969 1 0 1 1 0 8 0 amappl8 128 510 0 471 2 0 2 2 0 8 0 amappl7 120 648 0 641 1 0 1 1 0 8 0 amappl6 112 179 0 170 1 0 1 1 0 8 0 amappl5 104 309 0 298 1 0 1 1 0 8 0 amappl4 96 3029 0 2996 1 0 1 1 0 8 0 amappl3 88 357 0 350 1 0 1 1 0 8 0 amappl2 80 19291 0 19211 3 1 2 3 0 8 0 amappl1 72 56891 0 56457 24 14 10 20 0 8 0 amappl 80 5962 0 5912 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 64 140 0 11 3 0 3 3 0 8 0 uaddrrnd 24 2589 0 2544 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2589 0 2544 1 0 1 1 0 8 0 vmmpekpl 168 19303 0 19267 2 0 2 2 0 8 0 vmmpepl 168 324171 0 321745 253 123 130 170 0 357 23 vmsppl 272 2558 0 2544 4 3 1 2 0 8 0 pdppl 4096 5184 0 5130 9 2 7 7 0 8 0 pvpl 32 951319 0 929114 364 144 220 298 0 265 32 pmappl 200 2588 0 2556 2 0 2 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 672 0 132 16 0 16 16 0 8 0