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 *508486 34383 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(ffffffff821e3913,ffffffff821ff6e1,2cc,ffffffff8216ac2c) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802c20b468) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff82556fa8) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffeed0) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffeed0) 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(ffffffff821e3913,ffffffff821ff6e1,2cc,ffffffff8216ac2c) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802c20b468) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff82556fa8) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffeed0) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffeed0) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014811ea0 rbx 0xffff800014811f50 rdx 0x2 rcx 0 rax 0 r8 0xffff800014811e60 r9 0x1 r10 0 r11 0x7f5ef6c93fbe6ea1 r12 0x3000000008 r13 0xffff800014811eb0 r14 0x100 r15 0x1 rip 0xffffffff818bd9d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800014811e90 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=508486 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff148,0xffff8000ffffec68 process=0xffff8000ffffca20 user=0xffff80001480d000, vmspace=0xffffffff82559af0 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 83716 440862 65037 0 3 0x82 wait syz-executor.0 92314 184218 65037 0 3 0x82 wait syz-executor.1 88439 9834 1 0 3 0x100083 ttyin getty 25933 152925 0 0 3 0x14200 bored sosplice 65037 417622 83852 0 3 0x82 thrsleep syz-fuzzer 65037 212211 83852 0 2 0x4000482 syz-fuzzer 65037 192556 83852 0 3 0x4000082 kqread syz-fuzzer 65037 446953 83852 0 3 0x4000082 thrsleep syz-fuzzer 65037 187510 83852 0 2 0x4000482 syz-fuzzer 65037 288976 83852 0 3 0x4000082 thrsleep syz-fuzzer 65037 257151 83852 0 3 0x4000082 thrsleep syz-fuzzer 65037 264519 83852 0 3 0x4000082 thrsleep syz-fuzzer 83852 393183 85538 0 3 0x10008a pause ksh 85538 480830 9589 0 3 0x92 select sshd 9589 461093 1 0 3 0x80 select sshd 30124 259205 24921 73 2 0x100010 syslogd 24921 459814 1 0 3 0x100082 netio syslogd 70716 385109 0 0 2 0x14200 zerothread 98344 366512 0 0 3 0x14200 aiodoned aiodoned 75597 330436 0 0 2 0x14200 update 9328 449082 0 0 3 0x14200 cleaner cleaner 2622 369102 0 0 2 0x14200 reaper 971 457716 0 0 3 0x14200 pgdaemon pagedaemon 43464 2278 0 0 3 0x14200 bored crynlk 85363 9011 0 0 3 0x14200 bored crypto 95377 267174 0 0 3 0x40014200 acpi0 acpi0 43183 200090 0 0 2 0x14200 softnet 73397 68971 0 0 2 0x14200 systqmp 41212 300581 0 0 3 0x14200 bored systq *34383 508486 0 0 7 0x40014200 softclock 31596 140402 0 0 3 0x40014200 idle0 81315 78660 0 0 3 0x14200 bored smr 1 473841 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 9639 6361K 9330K 78643K 88289 0 0 pcb 13 12K 14K 78643K 2870 0 0 rtable 111 12K 14K 78643K 6031 0 0 ifaddr 114 32K 41K 78643K 2422 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 1062 0 0 iov 0 0K 28K 78643K 9209 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1233 77K 78K 78643K 24288 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 180 0 0 VM map 80 20K 20K 78643K 145 0 0 sem 12 0K 0K 78643K 3219 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 4 9K 25K 78643K 14289 0 0 sigio 1 0K 0K 78643K 205 0 0 proc 45 30K 63K 78643K 4837 0 0 subproc 32 2K 2K 78643K 1389 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 1169 0 0 in_multi 22 1K 2K 78643K 1481 0 0 ether_multi 1 0K 0K 78643K 143 0 0 mrt 3 0K 0K 78643K 108 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 186 821K 821K 78643K 186 0 0 exec 0 0K 1K 78643K 2880 0 0 pfkey data 0 0K 4K 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 237 656K 656K 78643K 37921 0 0 UVM aobj 130 7K 7K 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 1K 78643K 3638 0 0 NDP 26 0K 1K 78643K 769 0 0 temp 267 3545K 4186K 78643K 963868 0 0 kqueue 0 0K 0K 78643K 127 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 64 275 0 269 1 0 1 1 0 8 0 rtpcb 80 1489 0 1489 14 14 0 1 0 8 0 rtentry 112 1423 0 1386 2 0 2 2 0 8 0 unpcb 120 7201 0 7183 13 12 1 2 0 8 0 syncache 264 81 0 81 32 32 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 130 0 130 23 23 0 1 0 8 0 tcpcb 544 11953 0 11949 124 123 1 15 0 8 0 ipq 40 107 0 107 38 38 0 1 0 8 0 ipqe 40 2569 0 2569 38 38 0 1 0 8 0 inpcb 280 22921 0 22917 128 127 1 13 0 8 0 rttmr 72 38 0 37 8 7 1 1 0 8 0 ip6q 72 6 0 6 5 5 0 1 0 8 0 ip6af 40 14 0 14 5 5 0 1 0 8 0 nd6 48 184 0 184 10 10 0 1 0 8 0 pkpcb 40 50 0 50 22 22 0 1 0 8 0 swfcl 56 4 0 0 1 0 1 1 0 8 0 ppxss 1128 311 0 311 55 55 0 1 0 8 0 art_heap8 4096 36 0 34 19 17 2 4 0 8 0 art_heap4 256 5938 0 5711 96 78 18 21 0 8 0 art_table 32 5974 0 5745 5 2 3 3 0 8 0 art_node 16 1417 0 1383 1 0 1 1 0 8 0 semapl 112 3217 0 3207 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 24676 0 23217 50 2 48 48 0 8 0 ffsino 240 24676 0 23217 87 1 86 86 0 8 0 nchpl 144 46579 0 46070 61 41 20 60 0 8 0 uvmvnodes 72 8594 0 0 157 0 157 157 0 8 0 vnodes 208 8594 0 0 453 0 453 453 0 8 0 namei 1024 180904 0 180904 5 5 0 1 0 8 0 vcpupl 1984 79 0 1 10 0 10 10 0 8 0 vmpool 520 143 0 65 7 1 6 6 0 8 0 scsiplug 64 5 0 5 3 3 0 1 0 8 0 scxspl 192 165568 0 165568 99 98 1 7 0 8 1 plimitpl 152 1218 0 1211 1 0 1 1 0 8 0 sigapl 432 14233 0 14223 2 0 2 2 0 8 0 futexpl 56 457621 0 457621 4 4 0 1 0 8 0 knotepl 112 3948 0 3929 7 6 1 3 0 8 0 kqueuepl 104 4819 0 4817 25 24 1 4 0 8 0 pipepl 112 8546 0 8527 30 29 1 2 0 8 0 fdescpl 424 14234 0 14223 2 0 2 2 0 8 0 filepl 120 137526 0 137442 106 103 3 11 0 8 0 lockfpl 104 7393 0 7393 2 2 0 1 0 8 0 lockfspl 48 2453 0 2453 2 2 0 1 0 8 0 sessionpl 112 106 0 98 1 0 1 1 0 8 0 pgrppl 48 281 0 273 1 0 1 1 0 8 0 ucredpl 96 19404 0 19393 1 0 1 1 0 8 0 zombiepl 144 14227 0 14225 1 0 1 1 0 8 0 processpl 864 14253 0 14225 4 0 4 4 0 8 0 procpl 632 32915 0 32876 6 2 4 5 0 8 0 sosppl 128 256 0 256 53 53 0 1 0 8 0 sockpl 384 31866 0 31844 191 188 3 21 0 8 0 mcl64k 65536 5506 0 5506 482 482 0 65 0 8 0 mcl16k 16384 207 0 207 55 55 0 1 0 8 0 mcl12k 12288 415 0 415 49 49 0 1 0 8 0 mcl9k 9216 293 0 293 48 48 0 1 0 8 0 mcl8k 8192 683 0 683 23 23 0 1 0 8 0 mcl4k 4096 1724 0 1724 8 8 0 1 0 8 0 mcl2k2 2112 155 0 155 57 57 0 1 0 8 0 mcl2k 2048 95989 0 95938 41 34 7 16 0 8 0 mtagpl 80 622 0 622 19 19 0 1 0 8 0 mbufpl 256 273542 0 273473 529 518 11 40 0 8 0 bufpl 256 63667 0 55027 541 0 541 541 0 8 0 anonpl 16 1842211 0 1818466 394 298 96 98 0 62 0 amapchunkpl 152 77640 0 77238 239 223 16 20 0 158 0 amappl16 192 91355 0 90205 662 604 58 70 0 8 0 amappl15 184 2512 0 2509 1 0 1 1 0 8 0 amappl14 176 2869 0 2864 1 0 1 1 0 8 0 amappl13 168 1627 0 1627 13 13 0 1 0 8 0 amappl12 160 2438 0 2435 1 0 1 1 0 8 0 amappl11 152 1623 0 1616 1 0 1 1 0 8 0 amappl10 144 2127 0 2127 10 10 0 1 0 8 0 amappl9 136 3191 0 3185 1 0 1 1 0 8 0 amappl8 128 2690 0 2640 2 0 2 2 0 8 0 amappl7 120 2435 0 2427 1 0 1 1 0 8 0 amappl6 112 1405 0 1390 1 0 1 1 0 8 0 amappl5 104 3274 0 3265 1 0 1 1 0 8 0 amappl4 96 13305 0 13277 1 0 1 1 0 8 0 amappl3 88 4326 0 4310 1 0 1 1 0 8 0 amappl2 80 110821 0 110744 3 1 2 3 0 8 0 amappl1 72 272893 0 272469 27 18 9 20 0 8 0 amappl 80 34575 0 34489 3 1 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 14377 0 14222 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 14377 0 14222 1 0 1 1 0 8 0 vmmpekpl 168 90749 0 90706 4 1 3 3 0 8 0 vmmpepl 168 1746756 0 1744297 879 767 112 146 0 357 0 vmsppl 272 14233 0 14221 6 5 1 2 0 8 0 pdppl 4096 28760 0 28650 24 10 14 14 0 8 0 pvpl 32 4712149 0 4689644 1012 700 312 325 0 265 122 pmappl 200 14376 0 14286 8 3 5 5 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 2045 0 1361 25 4 21 22 0 8 0