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 *322099 60431 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(ffffffff821e4280,ffffffff821ff4ab,2cc,ffffffff8216cea0) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802d923008) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825570b8) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000fffff148) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000fffff148) 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(ffffffff821e4280,ffffffff821ff4ab,2cc,ffffffff8216cea0) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802d923008) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825570b8) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000fffff148) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000fffff148) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014812cc0 rbx 0xffff800014812d70 rdx 0x2 rcx 0 rax 0 r8 0xffff800014812c80 r9 0x1 r10 0 r11 0x2c9d8684526ddbd r12 0x3000000008 r13 0xffff800014812cd0 r14 0x100 r15 0x1 rip 0xffffffff82159ec8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800014812cb0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=322099 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff638,0xffff8000ffffeee0 process=0xffff8000ffffc000 user=0xffff80001480d000, vmspace=0xffffffff82564460 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 93046 64320 69718 0 3 0x82 wait syz-executor.0 87982 383488 69718 0 3 0x82 wait syz-executor.1 64422 515205 0 0 3 0x14200 acct acct 61063 87128 0 0 3 0x14200 bored sosplice 69718 494838 40896 0 3 0x82 thrsleep syz-fuzzer 69718 84922 40896 0 2 0x4000482 syz-fuzzer 69718 96885 40896 0 3 0x4000082 thrsleep syz-fuzzer 69718 152985 40896 0 3 0x4000082 kqread syz-fuzzer 69718 154103 40896 0 3 0x4000082 thrsleep syz-fuzzer 69718 376504 40896 0 2 0x4000482 syz-fuzzer 69718 410510 40896 0 3 0x4000082 thrsleep syz-fuzzer 40896 401480 82628 0 3 0x10008a pause ksh 82628 142236 95943 0 3 0x92 select sshd 89345 94742 1 0 3 0x100083 ttyin getty 95943 12097 1 0 3 0x80 select sshd 35598 234908 29739 73 2 0x100010 syslogd 29739 517794 1 0 3 0x100082 netio syslogd 84506 164771 1 77 3 0x100090 poll dhclient 33191 296507 1 0 3 0x80 poll dhclient 83713 411639 0 0 2 0x14200 zerothread 41738 367022 0 0 3 0x14200 aiodoned aiodoned 51082 385753 0 0 2 0x14200 update 50603 91354 0 0 3 0x14200 cleaner cleaner 83719 430185 0 0 2 0x14200 reaper 33184 277848 0 0 3 0x14200 pgdaemon pagedaemon 65413 264175 0 0 3 0x14200 bored crynlk 23308 325316 0 0 3 0x14200 bored crypto 50047 449872 0 0 3 0x40014200 acpi0 acpi0 82836 123906 0 0 2 0x14200 softnet 59197 202056 0 0 2 0x14200 systqmp 29089 245837 0 0 3 0x14200 bored systq *60431 322099 0 0 7 0x40014200 softclock 34517 377743 0 0 3 0x40014200 idle0 51848 180272 0 0 3 0x14200 bored smr 1 15983 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 9576 7013K 7645K 78643K 15829 0 0 pcb 13 10K 12K 78643K 502 0 0 rtable 101 12K 13K 78643K 1860 0 0 ifaddr 86 17K 18K 78643K 389 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 162 0 0 iov 0 0K 24K 78643K 550 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1212 76K 77K 78643K 3241 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 32 0 0 VM map 35 8K 8K 78643K 53 0 0 sem 12 1K 1K 78643K 477 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 4 9K 25K 78643K 2283 0 0 sigio 0 0K 0K 78643K 39 0 0 proc 50 38K 55K 78643K 1133 0 0 subproc 32 2K 2K 78643K 303 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 162 0 0 in_multi 19 1K 2K 78643K 281 0 0 ether_multi 1 0K 0K 78643K 24 0 0 mrt 0 0K 0K 78643K 27 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 648 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 154 268K 268K 78643K 6595 0 0 UVM aobj 130 4K 4K 78643K 140 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 488 0 0 NDP 22 0K 0K 78643K 130 0 0 temp 240 3545K 4184K 78643K 55384 0 0 kqueue 0 0K 0K 78643K 26 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 91 0 85 1 0 1 1 0 8 0 rtpcb 80 963 0 961 1 0 1 1 0 8 0 rtentry 112 344 0 311 2 0 2 2 0 8 0 unpcb 120 1024 0 1014 1 0 1 1 0 8 0 syncache 264 15 0 15 6 6 0 1 0 8 0 tcpqe 32 88 0 88 5 5 0 1 0 8 0 tcpcb 544 1008 0 1004 18 17 1 15 0 8 0 ipq 40 17 0 17 7 7 0 1 0 8 0 ipqe 40 208 0 208 7 7 0 1 0 8 0 inpcb 280 2670 0 2663 18 17 1 9 0 8 0 rttmr 72 8 0 8 4 4 0 1 0 8 0 ip6q 72 1 0 1 1 1 0 1 0 8 0 ip6af 40 2 0 2 1 1 0 1 0 8 0 nd6 48 37 0 36 1 0 1 1 0 8 0 pkpcb 40 16 0 16 6 6 0 1 0 8 0 swfcl 56 2 0 0 1 0 1 1 0 8 0 ppxss 1128 28 0 28 11 11 0 1 0 8 0 art_heap8 4096 2 0 1 2 1 1 2 0 8 0 art_heap4 256 1339 0 1175 25 11 14 16 0 8 0 art_table 32 1341 0 1176 3 1 2 3 0 8 0 art_node 16 341 0 310 1 0 1 1 0 8 0 sysvmsgpl 40 21 0 13 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 473 0 463 1 0 1 1 0 8 0 shmpl 112 138 0 10 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 4825 0 3423 46 0 46 46 0 8 0 ffsino 240 4825 0 3423 83 0 83 83 0 8 0 nchpl 144 9661 0 9222 60 41 19 60 0 8 0 uvmvnodes 72 6343 0 0 116 0 116 116 0 8 0 vnodes 208 6343 0 0 334 0 334 334 0 8 0 namei 1024 31825 0 31825 3 3 0 1 0 8 0 vcpupl 1984 34 0 1 5 0 5 5 0 8 0 vmpool 520 51 0 18 4 1 3 3 0 8 0 scsiplug 64 3 0 3 3 3 0 1 0 8 0 scxspl 192 28191 0 28191 21 20 1 7 0 8 1 plimitpl 152 183 0 175 1 0 1 1 0 8 0 sigapl 432 2409 0 2397 2 0 2 2 0 8 0 futexpl 56 64131 0 64131 3 3 0 1 0 8 0 knotepl 112 628 0 609 1 0 1 1 0 8 0 kqueuepl 104 678 0 676 4 3 1 4 0 8 0 pipepl 112 1354 0 1335 5 4 1 2 0 8 0 fdescpl 424 2410 0 2397 2 0 2 2 0 8 0 filepl 120 21939 0 21844 15 12 3 10 0 8 0 lockfpl 104 884 0 883 1 0 1 1 0 8 0 lockfspl 48 269 0 268 1 0 1 1 0 8 0 sessionpl 112 32 0 22 1 0 1 1 0 8 0 pgrppl 48 56 0 46 1 0 1 1 0 8 0 ucredpl 96 2306 0 2299 1 0 1 1 0 8 0 zombiepl 144 2402 0 2400 1 0 1 1 0 8 0 processpl 864 2431 0 2400 4 0 4 4 0 8 0 procpl 632 5092 0 5052 5 1 4 5 0 8 0 sosppl 128 30 0 30 6 6 0 1 0 8 0 sockpl 384 4716 0 4697 22 19 3 14 0 8 0 mcl64k 65536 219 0 219 5 5 0 1 0 8 0 mcl16k 16384 31 0 31 8 8 0 1 0 8 0 mcl12k 12288 78 0 78 6 6 0 1 0 8 0 mcl9k 9216 38 0 38 10 10 0 1 0 8 0 mcl8k 8192 112 0 112 5 5 0 1 0 8 0 mcl4k 4096 233 0 233 3 3 0 1 0 8 0 mcl2k2 2112 25 0 25 11 11 0 1 0 8 0 mcl2k 2048 72779 0 72730 18 11 7 14 0 8 0 mtagpl 80 136 0 131 2 1 1 1 0 8 0 mbufpl 256 135458 0 135353 61 48 13 29 0 8 0 bufpl 256 18197 0 10670 471 0 471 471 0 8 0 anonpl 16 333788 0 310912 146 54 92 93 0 62 0 amapchunkpl 152 13440 0 13049 64 48 16 19 0 158 0 amappl16 192 15625 0 14538 159 104 55 67 0 8 0 amappl15 184 134 0 133 2 1 1 1 0 8 0 amappl14 176 422 0 416 1 0 1 1 0 8 0 amappl13 168 313 0 312 1 0 1 1 0 8 0 amappl12 160 460 0 459 2 1 1 1 0 8 0 amappl11 152 105 0 94 1 0 1 1 0 8 0 amappl10 144 454 0 452 2 1 1 1 0 8 0 amappl9 136 1144 0 1138 1 0 1 1 0 8 0 amappl8 128 672 0 641 2 0 2 2 0 8 0 amappl7 120 540 0 534 1 0 1 1 0 8 0 amappl6 112 91 0 78 1 0 1 1 0 8 0 amappl5 104 718 0 707 1 0 1 1 0 8 0 amappl4 96 2332 0 2299 1 0 1 1 0 8 0 amappl3 88 673 0 663 1 0 1 1 0 8 0 amappl2 80 17945 0 17865 3 1 2 3 0 8 0 amappl1 72 53971 0 53519 24 14 10 20 0 8 0 amappl 80 5604 0 5542 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 64 139 0 10 3 0 3 3 0 8 0 uaddrrnd 24 2461 0 2396 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2461 0 2396 1 0 1 1 0 8 0 vmmpekpl 168 17811 0 17770 2 0 2 2 0 8 0 vmmpepl 168 301367 0 299028 239 129 110 138 0 357 7 vmsppl 272 2409 0 2395 4 3 1 2 0 8 0 pdppl 4096 4928 0 4859 9 0 9 9 0 8 0 pvpl 32 879531 0 856737 434 126 308 319 0 265 112 pmappl 200 2460 0 2413 3 0 3 3 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 720 0 117 18 0 18 18 0 8 0