panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/main/kernel/sys/netinet/if_ether.c", line 758 Stopped at db_enter+0x1c: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 53966 79722 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82784dc6) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff828025ac,ffffffff828274c9,2f6,ffffffff82751df4) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd806b8fd5b8) at arptfree+0x131 sys/netinet/if_ether.c:758 arptimer(ffffffff82d460f8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82d460f8) at timeout_run+0x8f sys/kern/kern_timeout.c:665 softclock_thread(ffff8000215e9ff0) at softclock_thread+0xc4 sys/kern/kern_timeout.c:809 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 758 ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82784dc6) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff828025ac,ffffffff828274c9,2f6,ffffffff82751df4) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd806b8fd5b8) at arptfree+0x131 sys/netinet/if_ether.c:758 arptimer(ffffffff82d460f8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82d460f8) at timeout_run+0x8f sys/kern/kern_timeout.c:665 softclock_thread(ffff8000215e9ff0) at softclock_thread+0xc4 sys/kern/kern_timeout.c:809 end trace frame: 0x0, count: -7 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff8000215f6670 rbx 0 rdx 0 rcx 0 rax 0xffff8000215e9ff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0x2acb3c33e90e07df r11 0xa56c4caf2814dea6 r12 0 r13 0xfffffd806eb539a0 r14 0 r15 0x1 rip 0xffffffff82706dac db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff8000215f6660 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb> show proc PROC (softclock) tid=53966 pid=79722 tcnt=1 stat=onproc flags process=14000 proc=40000200 runpri=0, usrpri=50, slppri=0, nice=20 wchan=0x0, wmesg=, ps_single=0x0 forw=0xffffffffffffffff, list=0xffff8000215ea7e8,0xffff8000215e9d58 process=0xffff8000fffff3b0 user=0xffff8000215f1000, vmspace=0xffffffff82d4b320 estcpu=0, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 61684 179908 87670 0 2 0x480 syz-executor.5 61684 72193 87670 0 3 0x4000080 fifor syz-executor.5 61684 362080 87670 0 3 0x4000080 fsleep syz-executor.5 57008 43478 28118 0 3 0x82 piperd syz-executor.4 4652 481889 28118 0 3 0x82 piperd syz-executor.6 33994 421922 28118 0 3 0x82 piperd syz-executor.7 59734 286906 28118 0 3 0x82 piperd syz-executor.2 80082 348438 28118 0 3 0x82 piperd syz-executor.3 87670 147705 28118 0 3 0x82 nanoslp syz-executor.5 78516 366775 0 0 3 0x14280 nfsidl nfsio 78770 507459 0 0 3 0x14280 nfsidl nfsio 59877 241705 0 0 3 0x14280 nfsidl nfsio 54897 485532 0 0 3 0x14280 nfsidl nfsio 30881 484048 0 0 3 0x14280 nfsidl nfsio 40044 408619 0 0 3 0x14280 nfsidl nfsio 66363 322071 0 0 3 0x14280 nfsidl nfsio 39398 25921 0 0 3 0x14280 nfsidl nfsio 54316 216048 0 0 3 0x14280 nfsidl nfsio 36674 84815 0 0 3 0x14280 nfsidl nfsio 79427 65668 0 0 3 0x14280 nfsidl nfsio 9816 324790 0 0 3 0x14280 nfsidl nfsio 38442 163161 0 0 3 0x14280 nfsidl nfsio 45079 3024 0 0 3 0x14280 nfsidl nfsio 70148 487045 0 0 3 0x14280 nfsidl nfsio 28701 398949 0 0 3 0x14280 nfsidl nfsio 35343 87919 0 0 3 0x14280 nfsidl nfsio 28987 495185 0 0 3 0x14280 nfsidl nfsio 95643 267474 0 0 3 0x14280 nfsidl nfsio 49945 391427 0 0 3 0x14280 nfsidl nfsio 20483 150786 28118 0 3 0x82 piperd syz-executor.1 70271 272284 0 0 3 0x14200 acct acct 71917 473915 0 0 3 0x14200 bored sosplice 28118 299358 36992 0 3 0x2000082 wait syz-fuzzer 28118 115460 36992 0 3 0x6000082 thrsleep syz-fuzzer 28118 140525 36992 0 3 0x6000082 wait syz-fuzzer 28118 233036 36992 0 3 0x6000082 thrsleep syz-fuzzer 28118 302642 36992 0 3 0x6000082 wait syz-fuzzer 28118 221283 36992 0 3 0x6000082 thrsleep syz-fuzzer 28118 205432 36992 0 3 0x6000082 wait syz-fuzzer 28118 521806 36992 0 3 0x6000082 wait syz-fuzzer 28118 209606 36992 0 3 0x6000082 thrsleep syz-fuzzer 28118 300913 36992 0 3 0x6000082 kqread syz-fuzzer 28118 133807 36992 0 3 0x6000082 thrsleep syz-fuzzer 28118 58487 36992 0 3 0x6000082 wait syz-fuzzer 28118 287879 36992 0 3 0x6000082 wait syz-fuzzer 28118 79372 36992 0 3 0x6000082 wait syz-fuzzer 36992 428094 18506 0 3 0x10008a sigsusp ksh 18506 345652 43497 0 3 0x9a kqread sshd 74119 279532 1 0 3 0x100083 ttyopn getty 43497 115684 1 0 3 0x88 kqread sshd 24536 103077 27931 73 3 0x1100090 kqread syslogd 27931 192070 1 0 3 0x100082 netio syslogd 38362 523938 1 0 3 0x100080 kqread resolvd 10705 181102 95070 77 3 0x100092 kqread dhcpleased 13253 251614 95070 77 3 0x100092 kqread dhcpleased 95070 247679 1 0 3 0x80 kqread dhcpleased 97461 51422 0 0 3 0x14200 bored smr 92106 63097 0 0 3 0x14200 pgzero zerothread 5057 136399 0 0 3 0x14200 aiodoned aiodoned 78058 177895 0 0 3 0x14200 syncer update 82988 208876 0 0 3 0x14200 cleaner cleaner 83937 417784 0 0 3 0x14200 reaper reaper 30078 271237 0 0 3 0x14200 pgdaemon pagedaemon 90035 128394 0 0 3 0x14200 bored viomb 882 424605 0 0 3 0x40014200 acpi0 acpi0 94810 184819 0 0 3 0x14200 bored softnet3 17353 370183 0 0 3 0x14200 bored softnet2 47903 519696 0 0 3 0x14200 bored softnet1 29618 252158 0 0 3 0x14200 bored softnet0 9782 102178 0 0 3 0x14200 bored systqmp 85165 67586 0 0 3 0x14200 bored systq *79722 53966 0 0 7 0x40014200 softclock 48954 164734 0 0 3 0x40014200 idle0 1 476416 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 10213 6432K 8547K 78643K 40625 0 pcb 13 20K 24K 78643K 3579 0 rtable 241 7K 7K 78643K 2469 0 pf 34 9K 10K 78643K 464 0 ifaddr 45 13K 14K 78643K 419 0 ifgroup 59 2K 2K 78643K 711 0 sysctl 4 1K 5K 78643K 431 0 counters 30 17K 17K 78643K 238 0 ioctlops 0 0K 2K 78643K 890 0 iov 0 0K 28K 78643K 3043 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1661 104K 104K 78643K 15510 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 314 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 4836 0 dirhash 12 2K 2K 78643K 111 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 11 37K 69K 78643K 33223 0 sigio 0 0K 0K 78643K 502 0 proc 58 59K 75K 78643K 3025 0 subproc 104 6K 6K 78643K 785 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 633 0 in_multi 99 7K 7K 78643K 764 0 ether_multi 1 0K 0K 78643K 7 0 mrt 1 0K 0K 78643K 10 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 259 1155K 1155K 78643K 259 0 exec 0 0K 1K 78643K 6202 0 pfkey data 0 0K 0K 78643K 13 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 528 689K 695K 78643K 310337 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 1028 0 NDP 13 0K 2K 78643K 341 0 temp 80 5916K 6044K 78643K 193484 0 kqueue 12 18K 30K 78643K 1902 0 SYN cache 2 1236K 1244K 78643K 3 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 1034 0 1031 15 14 1 3 0 8 0 rtentry 112 715 0 603 4 0 4 4 0 8 0 unpcb 144 29000 0 28985 242 236 6 13 0 8 5 syncache 304 223 0 223 41 40 1 1 0 8 1 tcpqe 32 475 0 475 27 26 1 2 0 8 1 tcpcb 808 8932 0 8871 260 247 13 15 0 8 6 arp 88 127 0 108 1 0 1 1 0 8 0 ipq 40 13 0 12 7 6 1 1 0 8 0 ipqe 40 40 0 39 7 6 1 1 0 8 0 inpcb 336 25288 0 25224 300 288 12 18 0 8 5 nd6 104 190 0 165 1 0 1 1 0 8 0 pkpcb 40 316 0 316 17 17 0 1 0 8 0 kcovpl 48 60 0 52 1 0 1 1 0 8 0 ppxss 1160 97 0 97 26 26 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 2816 0 2349 33 3 30 30 0 8 0 art_table 32 2817 0 2349 4 0 4 4 0 8 0 art_node 16 697 0 595 1 0 1 1 0 8 0 sysvmsgpl 40 35 0 35 1 1 0 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 4833 0 4823 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 83 0 66 3 0 3 3 0 8 0 dino2pl 256 48920 0 47340 100 0 100 100 0 8 0 ffsino 240 48920 0 47340 94 0 94 94 0 8 0 nchpl 144 101992 0 101444 63 41 22 63 0 8 0 uvmvnodes 80 7873 0 0 161 0 161 161 0 8 0 vnodes 216 7873 0 0 438 0 438 438 0 8 0 namei 1024 329430 0 329430 25 24 1 3 0 8 1 vcpupl 2048 164 0 0 21 0 21 21 0 8 0 vmpool 664 204 0 40 16 2 14 14 0 8 0 kstatmem 264 442 0 416 2 0 2 2 0 8 0 scxspl 216 279696 0 279696 41 40 1 8 1 8 1 plimitpl 152 2622 0 2607 1 0 1 1 0 8 0 sigapl 424 33531 0 33471 11 3 8 8 0 8 0 futexpl 64 324164 0 324163 8 7 1 1 0 8 0 knotepl 120 282379 0 282301 96 93 3 17 0 8 0 kqueuepl 184 5601 0 5593 61 58 3 6 0 8 2 pipepl 288 5732 0 5705 110 106 4 9 0 8 0 fdescpl 432 33392 0 33370 6 2 4 4 0 8 0 filepl 120 231040 0 230808 267 253 14 19 0 8 4 lockfpl 104 11205 0 11203 15 14 1 2 0 8 0 lockfspl 48 4153 0 4151 1 0 1 1 0 8 0 sessionpl 144 75 0 59 1 0 1 1 0 8 0 pgrppl 48 582 0 566 1 0 1 1 0 8 0 ucredpl 104 24495 0 24479 1 0 1 1 0 8 0 zombiepl 144 33472 0 33471 1 0 1 1 0 8 0 processpl 1008 33531 0 33471 15 6 9 9 0 8 0 procpl 680 82697 0 82622 27 18 9 9 0 8 1 sosppl 168 213 0 213 29 28 1 1 0 8 1 sockpl 456 55743 0 55661 1209 1181 28 45 0 8 16 mcl64k 65536 1761 0 1761 28 27 1 1 0 8 1 mcl16k 16384 523 0 523 50 50 0 1 0 8 0 mcl12k 12288 1153 0 1153 34 33 1 1 0 8 1 mcl9k 9216 1427 0 1427 47 46 1 1 0 8 1 mcl8k 8192 2364 0 2364 32 31 1 1 0 8 1 mcl4k 4096 4241 0 4241 15 14 1 2 0 8 1 mcl2k2 2112 182 0 182 49 49 0 1 0 8 0 mcl2k 2048 139152 0 139096 106 97 9 29 0 8 0 mtagpl 96 3485 0 3485 35 35 0 26 0 8 0 mbufpl 256 494060 0 493902 606 594 12 107 0 8 0 bufpl 288 53573 0 45687 564 0 564 564 0 8 0 anonpl 24 2789827 0 2776384 321 213 108 119 0 188 8 amapchunkpl 152 963889 0 963169 157 121 36 46 0 158 0 amappl16 200 51551 0 51059 223 187 36 38 0 8 9 amappl15 192 21 0 21 3 3 0 1 0 8 0 amappl14 184 309 0 297 2 1 1 2 0 8 0 amappl13 176 13 0 13 1 1 0 1 0 8 0 amappl12 168 34792 0 34763 2 0 2 2 0 8 0 amappl11 160 49 0 39 1 0 1 1 0 8 0 amappl10 152 95 0 83 2 1 1 1 0 8 0 amappl9 144 364 0 362 1 0 1 1 0 8 0 amappl8 136 1027 0 868 6 0 6 6 0 8 0 amappl7 128 176 0 160 2 0 2 2 0 8 0 amappl6 120 755 0 733 2 1 1 2 0 8 0 amappl5 112 1404 0 1395 1 0 1 1 0 8 0 amappl4 104 1329 0 1286 2 0 2 2 0 8 0 amappl3 96 191724 0 191657 5 2 3 3 0 8 0 amappl2 88 34830 0 34765 3 1 2 3 0 8 0 amappl1 80 130775 0 130282 22 11 11 22 0 8 0 amappl 88 304218 0 303979 9 2 7 7 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 33596 0 33410 2 0 2 2 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 33596 0 33410 2 0 2 2 0 8 0 vmmpekpl 168 209510 0 209422 5 0 5 5 0 8 0 vmmpepl 168 1934810 0 1932528 469 340 129 135 0 357 0 vmsppl 368 33595 0 33410 20 2 18 18 0 8 0 rwobjpl 24 429617 0 419998 64 4 60 60 0 8 0 pdppl 4096 67199 0 66984 1187 958 229 229 0 8 14 pvpl 32 8341709 0 8322952 735 543 192 357 0 265 17 pmappl 216 33595 0 33410 11 0 11 11 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 3585 0 2461 33 0 33 33 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82784dc6) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff828025ac,ffffffff828274c9,2f6,ffffffff82751df4) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd806b8fd5b8) at arptfree+0x131 sys/netinet/if_ether.c:758 arptimer(ffffffff82d460f8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82d460f8) at timeout_run+0x8f sys/kern/kern_timeout.c:665 softclock_thread(ffff8000215e9ff0) at softclock_thread+0xc4 sys/kern/kern_timeout.c:809 end trace frame: 0x0, count: -7 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82784dc6) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff828025ac,ffffffff828274c9,2f6,ffffffff82751df4) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd806b8fd5b8) at arptfree+0x131 sys/netinet/if_ether.c:758 arptimer(ffffffff82d460f8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82d460f8) at timeout_run+0x8f sys/kern/kern_timeout.c:665 softclock_thread(ffff8000215e9ff0) at softclock_thread+0xc4 sys/kern/kern_timeout.c:809 end trace frame: 0x0, count: -7