panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/main/kernel/sys/netinet/if_ether.c", line 776 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *183771 75070 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8258252d) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff825f371a,ffffffff826184ee,308,ffffffff8254ea12) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807bec8540) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82acebe0) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82acebe0) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffefc0) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: 8 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 *cpu0: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/main/kernel/sys/netinet/if_ether.c", line 776 ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8258252d) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff825f371a,ffffffff826184ee,308,ffffffff8254ea12) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807bec8540) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82acebe0) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82acebe0) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffefc0) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff8000216845d0 rbx 0 rdx 0 rcx 0 rax 0xffff8000ffffefc0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xf0bc4d96b877d759 r11 0xf229338ebb115cdb r12 0 r13 0xfffffd807bfc2108 r14 0 r15 0x1 rip 0xffffffff811e3298 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000216845c0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=183771 stat=onproc flags process=14000 proc=40000200 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffffa40,0xffff8000ffffed30 process=0xffff8000ffffc000 user=0xffff80002167f000, vmspace=0xffffffff82a7b3f8 estcpu=0, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 97546 203857 1099 0 2 0 syz-executor.5 97546 362719 1099 0 2 0x4000000 syz-executor.5 77203 400329 20099 0 2 0x480 syz-executor.7 77203 250599 20099 0 3 0x4000080 fsleep syz-executor.7 88516 187671 77998 0 2 0x482 syz-executor.4 1099 202024 77998 0 2 0x482 syz-executor.5 2685 467187 77998 0 2 0x2 syz-executor.3 31572 123779 77998 0 2 0x482 syz-executor.6 63654 417094 77998 0 2 0x482 syz-executor.2 10710 218471 0 0 3 0x14280 nfsidl nfsio 10434 356147 0 0 3 0x14280 nfsidl nfsio 74637 47800 0 0 3 0x14280 nfsidl nfsio 54608 120316 0 0 3 0x14280 nfsidl nfsio 65513 368297 0 0 3 0x14280 nfsidl nfsio 2481 478001 0 0 3 0x14280 nfsidl nfsio 23450 240637 0 0 3 0x14280 nfsidl nfsio 39151 192538 0 0 3 0x14280 nfsidl nfsio 40172 290681 0 0 3 0x14280 nfsidl nfsio 69947 144964 0 0 3 0x14280 nfsidl nfsio 88327 43711 0 0 3 0x14280 nfsidl nfsio 97645 311587 0 0 3 0x14280 nfsidl nfsio 54043 113298 0 0 3 0x14280 nfsidl nfsio 37481 183365 0 0 3 0x14280 nfsidl nfsio 56552 173837 0 0 3 0x14280 nfsidl nfsio 57914 380133 0 0 3 0x14280 nfsidl nfsio 30312 499174 0 0 3 0x14280 nfsidl nfsio 66584 516047 0 0 3 0x14280 nfsidl nfsio 38493 16148 0 0 3 0x14280 nfsidl nfsio 41369 106571 0 0 3 0x14280 nfsidl nfsio 94655 415256 0 0 3 0x14200 bored sosplice 20099 442151 77998 0 2 0x482 syz-executor.7 78275 426399 77998 0 2 0x2 syz-executor.1 77998 116750 86703 0 3 0x82 thrsleep syz-fuzzer 77998 245904 86703 0 3 0x4000082 nanoslp syz-fuzzer 77998 95757 86703 0 3 0x4000082 wait syz-fuzzer 77998 228096 86703 0 3 0x4000082 wait syz-fuzzer 77998 56652 86703 0 3 0x4000082 wait syz-fuzzer 77998 144798 86703 0 3 0x4000082 thrsleep syz-fuzzer 77998 288006 86703 0 3 0x4000082 wait syz-fuzzer 77998 504815 86703 0 3 0x4000082 thrsleep syz-fuzzer 77998 294871 86703 0 3 0x4000082 wait syz-fuzzer 77998 99267 86703 0 3 0x4000082 wait syz-fuzzer 77998 414629 86703 0 3 0x4000082 wait syz-fuzzer 77998 515659 86703 0 3 0x4000082 thrsleep syz-fuzzer 77998 313493 86703 0 2 0x4000482 syz-fuzzer 77998 125229 86703 0 3 0x4000082 wait syz-fuzzer 86703 75251 19049 0 3 0x10008a sigsusp ksh 19049 95136 10142 0 3 0x9a kqread sshd 96731 48885 1 0 3 0x100083 ttyin getty 10142 275473 1 0 3 0x88 kqread sshd 26440 454717 38814 73 2 0x1100010 syslogd 38814 313335 1 0 3 0x100082 netio syslogd 90095 377163 1 0 3 0x100080 kqread resolvd 96371 78071 91440 77 3 0x100092 kqread dhcpleased 14190 485089 91440 77 3 0x100092 kqread dhcpleased 91440 176019 1 0 3 0x80 kqread dhcpleased 50532 251544 0 0 3 0x14200 bored smr 50491 270175 0 0 2 0x14200 zerothread 89232 338779 0 0 3 0x14200 aiodoned aiodoned 83605 79637 0 0 3 0x14200 syncer update 41546 436029 0 0 3 0x14200 cleaner cleaner 91616 481655 0 0 3 0x14200 reaper reaper 54545 466453 0 0 3 0x14200 pgdaemon pagedaemon 58562 221847 0 0 3 0x14200 bored viomb 27817 373379 0 0 3 0x40014200 acpi0 acpi0 76201 187976 0 0 3 0x14200 bored softnet 20804 484468 0 0 3 0x14200 bored softnet 8030 491553 0 0 3 0x14200 bored softnet 86393 337388 0 0 3 0x14200 bored softnet 20978 180896 0 0 3 0x14200 bored systqmp 79583 121151 0 0 3 0x14200 bored systq *75070 183771 0 0 7 0x40014200 softclock 19278 97951 0 0 3 0x40014200 idle0 1 106666 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 devbuf 10199 6429K 6927K 78643K 17259 0 pcb 13 14K 16K 78643K 760 0 rtable 225 10K 10K 78643K 1273 0 ifaddr 90 21K 21K 78643K 427 0 sysctl 2 0K 0K 78643K 2 0 counters 28 17K 17K 78643K 196 0 ioctlops 0 0K 4K 78643K 677 0 iov 0 0K 28K 78643K 1308 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1554 97K 98K 78643K 5079 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 48 0 VM map 2 0K 0K 78643K 2 0 sem 12 1K 1K 78643K 142 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 12 41K 73K 78643K 4077 0 sigio 0 0K 0K 78643K 90 0 proc 58 59K 75K 78643K 995 0 subproc 104 6K 10K 78643K 366 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 358 0 in_multi 95 6K 6K 78643K 321 0 ether_multi 1 0K 0K 78643K 26 0 mrt 1 0K 0K 78643K 31 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 61 281K 281K 78643K 61 0 exec 0 0K 1K 78643K 1055 0 pfkey data 0 0K 0K 78643K 5 0 tdb 3 0K 0K 78643K 3 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 8 62K 64K 78643K 10 0 UVM amap 324 274K 275K 78643K 28353 0 UVM aobj 131 4K 4K 78643K 131 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 149 0 NDP 13 0K 1K 78643K 138 0 temp 132 4686K 5710K 78643K 83118 0 kqueue 13 20K 28K 78643K 420 0 SYN cache 2 16K 16K 78643K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 385 0 382 6 5 1 3 0 8 0 rtentry 112 367 0 270 4 0 4 4 0 8 0 unpcb 144 4060 0 4046 46 44 2 10 0 8 1 syncache 296 34 0 34 6 6 0 1 0 8 0 tcpqe 32 86 0 86 6 6 0 1 0 8 0 tcpcb 776 1342 0 1338 37 33 4 8 0 8 3 arp 88 44 0 27 1 0 1 1 0 8 0 ipq 40 2 0 2 1 1 0 1 0 8 0 ipqe 40 9 0 9 1 1 0 1 0 8 0 inpcb 336 7104 0 7097 65 61 4 13 0 8 3 nd6 48 65 0 42 1 0 1 1 0 8 0 pkpcb 40 75 0 75 2 2 0 1 0 8 0 kcovpl 48 20 0 12 1 0 1 1 0 8 0 ppxss 1160 117 0 117 6 6 0 1 0 8 0 pppxif 1352 13 0 13 3 3 0 1 0 8 0 pfstscr 40 96 0 93 6 5 1 1 0 8 0 pfanchor 1280 716 14 204 46 3 43 43 0 8 0 pfqueue 264 2 0 2 1 1 0 1 0 8 0 pfstitem 24 62 0 42 1 0 1 1 0 8 0 pfstkey 128 207 0 172 2 0 2 2 0 8 0 pfstate 352 105 0 95 1 0 1 1 0 8 0 rttmr 136 8 0 8 3 3 0 1 0 8 0 art_heap8 4096 6 0 5 4 3 1 3 0 8 0 art_heap4 256 1694 0 1245 37 8 29 29 0 8 0 art_table 32 1700 0 1250 4 0 4 4 0 8 0 art_node 16 363 0 278 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 2 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 102 0 92 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 7422 0 5974 91 0 91 91 0 8 0 ffsino 240 7422 0 5974 86 0 86 86 0 8 0 nchpl 144 13493 0 11859 63 0 63 63 0 8 0 rtmask 32 3 0 3 1 1 0 1 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 49959 0 49958 2 1 1 2 0 8 0 vcpupl 2048 46 0 0 6 0 6 6 0 8 0 vmpool 536 59 0 13 6 2 4 4 0 8 0 kstatmem 264 194 0 168 6 4 2 3 0 8 0 scsiplug 72 5 0 5 2 2 0 1 0 8 0 scxspl 216 34863 0 34863 15 14 1 8 0 8 1 plimitpl 152 511 0 496 1 0 1 1 0 8 0 sigapl 424 4366 0 4302 8 0 8 8 0 8 0 futexpl 64 45447 0 45446 1 0 1 1 0 8 0 knotepl 120 58800 0 58586 36 27 9 9 0 8 2 kqueuepl 184 937 0 928 18 17 1 6 0 8 0 pipepl 288 1522 0 1495 36 33 3 7 0 8 0 fdescpl 432 4329 0 4306 4 0 4 4 0 8 0 filepl 120 37824 0 37587 50 41 9 16 0 8 0 lockfpl 104 1772 0 1770 7 6 1 2 0 8 0 lockfspl 48 341 0 339 1 0 1 1 0 8 0 sessionpl 144 35 0 19 1 0 1 1 0 8 0 pgrppl 48 42 0 26 1 0 1 1 0 8 0 ucredpl 104 4932 0 4922 1 0 1 1 0 8 0 zombiepl 144 4307 0 4302 1 0 1 1 0 8 0 processpl 1008 4366 0 4302 10 1 9 9 0 8 0 procpl 672 11151 0 11072 17 9 8 9 0 8 0 sosppl 168 58 0 58 4 4 0 1 0 8 0 sockpl 456 11627 0 11603 266 257 9 34 0 8 5 mcl64k 65536 419 0 419 8 8 0 1 0 8 0 mcl16k 16384 113 0 113 8 8 0 1 0 8 0 mcl12k 12288 239 0 239 10 10 0 1 0 8 0 mcl9k 9216 32 0 32 9 8 1 1 0 8 1 mcl8k 8192 430 0 430 6 5 1 1 0 8 1 mcl4k 4096 567 0 567 4 3 1 1 0 8 1 mcl2k2 2112 35 0 35 11 11 0 1 0 8 0 mcl2k 2048 85129 0 85062 44 33 11 35 0 8 1 mtagpl 96 507 0 457 7 2 5 5 0 8 0 mbufpl 256 1547481 0 1547256 252 224 28 71 0 8 2 bufpl 288 10180 0 3774 458 0 458 458 0 8 0 anonpl 24 870548 0 854248 139 29 110 126 0 188 0 amapchunkpl 152 84062 0 83428 54 25 29 42 0 158 0 amappl16 200 8926 0 8320 55 20 35 41 0 8 0 amappl15 192 5 0 5 1 1 0 1 0 8 0 amappl14 184 202 0 187 2 0 2 2 0 8 0 amappl13 176 9 0 9 1 1 0 1 0 8 0 amappl12 168 565 0 558 1 0 1 1 0 8 0 amappl11 160 43 0 33 1 0 1 1 0 8 0 amappl10 152 42 0 33 1 0 1 1 0 8 0 amappl9 144 975 0 972 1 0 1 1 0 8 0 amappl8 136 253 0 189 3 0 3 3 0 8 0 amappl7 128 171 0 147 2 0 2 2 0 8 0 amappl6 120 218 0 207 1 0 1 1 0 8 0 amappl5 112 216 0 210 1 0 1 1 0 8 0 amappl4 104 686 0 658 2 1 1 2 0 8 0 amappl3 96 12192 0 12151 2 0 2 2 0 8 0 amappl2 88 4919 0 4852 3 1 2 3 0 8 0 amappl1 80 99336 0 98693 25 9 16 22 0 8 0 amappl 88 27612 0 27443 5 0 5 5 0 92 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 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 18 0 17 1 0 1 1 0 8 0 aobjpl 72 130 0 0 3 0 3 3 0 8 0 uaddrrnd 24 4388 0 4319 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4388 0 4319 1 0 1 1 0 8 0 vmmpekpl 168 38445 0 38377 5 1 4 4 0 8 0 vmmpepl 168 401415 0 398909 250 114 136 180 0 357 3 vmsppl 272 4387 0 4319 7 2 5 5 0 8 0 rwobjpl 24 110886 0 103174 49 1 48 48 0 8 0 pdppl 4096 8782 0 8684 316 208 108 110 0 8 10 pvpl 32 1781119 0 1759971 301 108 193 269 0 265 0 pmappl 216 4387 0 4319 5 0 5 5 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1436 0 599 26 0 26 26 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8258252d) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff825f371a,ffffffff826184ee,308,ffffffff8254ea12) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807bec8540) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82acebe0) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82acebe0) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffefc0) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8258252d) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff825f371a,ffffffff826184ee,308,ffffffff8254ea12) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807bec8540) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82acebe0) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82acebe0) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffefc0) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7