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 *314433 75045 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8272a2bf) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a205b,ffffffff827c6cc6,308,ffffffff826f52b3) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807e54b780) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82cc4328) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82cc4328) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffe2b8) 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(ffffffff8272a2bf) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a205b,ffffffff827c6cc6,308,ffffffff826f52b3) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807e54b780) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82cc4328) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82cc4328) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffe2b8) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800021604720 rbx 0 rdx 0 rcx 0 rax 0xffff8000ffffe2b8 r8 0x101010101010101 r9 0x8080808080808080 r10 0x8923a438588c6f79 r11 0x3fe43c6dc1527fc6 r12 0 r13 0xfffffd806eb03d10 r14 0 r15 0x1 rip 0xffffffff81805f78 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021604710 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=314433 stat=onproc flags process=14000 proc=40000200 pri=50, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff5c0,0xffff8000ffffe010 process=0xffff8000ffffc7e0 user=0xffff8000215ff000, vmspace=0xffffffff82c09bc8 estcpu=1, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 96030 222875 70946 0 3 0x82 wait syz-executor.4 76051 291512 0 0 3 0x14280 nfsidl nfsio 61708 180243 0 0 3 0x14280 nfsidl nfsio 96995 383553 0 0 3 0x14280 nfsidl nfsio 95388 200338 0 0 3 0x14280 nfsidl nfsio 17463 107911 0 0 3 0x14280 nfsidl nfsio 35426 211897 0 0 3 0x14280 nfsidl nfsio 62352 76408 0 0 3 0x14280 nfsidl nfsio 16751 372681 0 0 3 0x14280 nfsidl nfsio 3203 461059 0 0 3 0x14280 nfsidl nfsio 19153 135087 0 0 3 0x14280 nfsidl nfsio 49949 220749 0 0 3 0x14280 nfsidl nfsio 36241 254599 0 0 3 0x14280 nfsidl nfsio 96517 131078 0 0 3 0x14280 nfsidl nfsio 53557 150032 0 0 3 0x14280 nfsidl nfsio 32773 504900 0 0 3 0x14280 nfsidl nfsio 10240 392653 0 0 3 0x14280 nfsidl nfsio 99066 175501 0 0 3 0x14280 nfsidl nfsio 24129 407032 0 0 3 0x14280 nfsidl nfsio 48959 96296 0 0 3 0x14280 nfsidl nfsio 45913 421043 0 0 3 0x14280 nfsidl nfsio 23484 281108 70946 0 2 0x2 syz-executor.7 51667 485244 1 0 3 0x100083 ttyin getty 82009 318520 70946 0 2 0x2 syz-executor.3 98285 363651 70946 0 2 0x2 syz-executor.2 29840 184854 70946 0 3 0x82 wait syz-executor.6 80925 375782 70946 0 3 0x82 wait syz-executor.5 8796 33596 70946 0 2 0x2 syz-executor.1 45414 456574 0 0 3 0x14200 bored sosplice 70946 60183 89312 0 3 0x82 wait syz-fuzzer 70946 498545 89312 0 3 0x4000082 nanoslp syz-fuzzer 70946 301939 89312 0 3 0x4000082 wait syz-fuzzer 70946 510632 89312 0 3 0x4000082 thrsleep syz-fuzzer 70946 506704 89312 0 3 0x4000082 thrsleep syz-fuzzer 70946 164 89312 0 3 0x4000082 thrsleep syz-fuzzer 70946 304247 89312 0 3 0x4000082 wait syz-fuzzer 70946 451489 89312 0 2 0x4000482 syz-fuzzer 70946 174039 89312 0 3 0x4000082 thrsleep syz-fuzzer 70946 390416 89312 0 3 0x4000082 wait syz-fuzzer 70946 387535 89312 0 3 0x4000082 wait syz-fuzzer 70946 177387 89312 0 3 0x4000082 wait syz-fuzzer 70946 82699 89312 0 3 0x4000082 wait syz-fuzzer 70946 433003 89312 0 3 0x4000082 wait syz-fuzzer 89312 348288 71196 0 3 0x10008a sigsusp ksh 71196 467412 78565 0 3 0x9a kqread sshd 78565 172964 1 0 3 0x88 kqread sshd 62173 409559 69245 73 2 0x1100010 syslogd 69245 132279 1 0 3 0x100082 netio syslogd 30117 199488 1 0 3 0x100080 kqread resolvd 53776 463499 33793 77 3 0x100092 kqread dhcpleased 61449 258240 33793 77 3 0x100092 kqread dhcpleased 33793 125132 1 0 3 0x80 kqread dhcpleased 32883 144416 0 0 3 0x14200 bored smr 53965 209043 0 0 2 0x14200 zerothread 76491 220979 0 0 3 0x14200 aiodoned aiodoned 97422 311989 0 0 2 0x14600 update 72532 108817 0 0 3 0x14200 cleaner cleaner 36072 488318 0 0 2 0x14200 reaper 89131 98419 0 0 3 0x14200 pgdaemon pagedaemon 64186 329079 0 0 3 0x14200 bored viomb 37883 6659 0 0 3 0x40014200 acpi0 acpi0 64791 229258 0 0 3 0x14200 bored softnet 39539 165165 0 0 3 0x14200 bored softnet 21599 440753 0 0 3 0x14200 bored softnet 71806 121103 0 0 3 0x14200 bored softnet 87140 170904 0 0 2 0x14200 systqmp 48760 364058 0 0 3 0x14200 bored systq *75045 314433 0 0 7 0x40014200 softclock 84663 346706 0 0 3 0x40014200 idle0 1 142876 0 0 3 0x80082 wait init 0 0 -1 0 2 0x10200 swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10215 6422K 6935K 78643K 19686 0 pcb 13 20K 24K 78643K 889 0 rtable 203 7K 7K 78643K 1636 0 ifaddr 78 22K 23K 78643K 409 0 sysctl 3 1K 1K 78643K 3 0 counters 27 17K 17K 78643K 136 0 ioctlops 0 0K 2K 78643K 1362 0 iov 0 0K 28K 78643K 537 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1668 104K 104K 78643K 6312 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 53 0 VM map 2 1K 1K 78643K 2 0 sem 14 3K 5K 78643K 143 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 10 33K 73K 78643K 4275 0 sigio 0 0K 0K 78643K 608 0 proc 58 59K 83K 78643K 1442 0 subproc 104 6K 6K 78643K 595 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 201 0 in_multi 79 5K 6K 78643K 541 0 ether_multi 1 0K 0K 78643K 30 0 mrt 1 0K 0K 78643K 19 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 217 970K 970K 78643K 217 0 exec 0 0K 1K 78643K 1568 0 pfkey data 0 0K 0K 78643K 9 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 312 91K 91K 78643K 27940 0 UVM aobj 131 6K 6K 78643K 137 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 104 0 NDP 11 0K 1K 78643K 159 0 temp 128 5770K 5834K 78643K 74366 0 kqueue 12 18K 26K 78643K 426 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 120 455 0 452 7 6 1 3 0 8 0 rtentry 112 520 0 430 4 1 3 4 0 8 0 unpcb 144 3017 0 3004 37 36 1 6 0 8 0 syncache 296 26 0 26 7 7 0 1 0 8 0 tcpqe 32 236 0 236 7 7 0 1 0 8 0 tcpcb 776 1296 0 1292 36 32 4 8 0 8 3 arp 88 83 0 66 1 0 1 1 0 8 0 ipq 40 2 0 1 2 1 1 1 0 8 0 ipqe 40 6 0 5 2 1 1 1 0 8 0 inpcb 336 7576 0 7569 64 61 3 18 0 8 2 nd6 48 127 0 105 1 0 1 1 0 8 0 pkpcb 40 12 0 12 2 2 0 1 0 8 0 kcovpl 48 38 0 30 1 0 1 1 0 8 0 ppxss 1160 61 0 61 6 6 0 1 0 8 0 pppxif 1360 47 0 47 5 5 0 1 0 8 0 pfstscr 40 1160 0 1151 1 0 1 1 0 8 0 pfosfp 40 14 0 11 1 0 1 1 0 8 0 pfosfpen 112 14 0 7 1 0 1 1 0 8 0 pfanchor 1280 662 12 150 44 1 43 43 0 8 0 pfqueue 264 3 0 3 1 1 0 1 0 8 0 pfstitem 24 174 0 152 1 0 1 1 0 8 0 pfstkey 128 1330 0 1173 6 0 6 6 0 8 0 pfstate 352 665 0 654 4 3 1 2 0 8 0 art_heap8 4096 2 0 1 2 1 1 2 0 8 0 art_heap4 256 2290 0 1938 39 16 23 29 0 8 0 art_table 32 2292 0 1939 5 1 4 4 0 8 0 art_node 16 515 0 437 1 0 1 1 0 8 0 sysvmsgpl 40 34 0 4 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 130 0 118 1 0 1 1 0 8 0 shmpl 112 134 0 6 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 6790 0 5347 91 0 91 91 0 8 0 ffsino 240 6792 0 5347 86 0 86 86 0 8 0 nchpl 144 12380 0 10746 63 1 62 63 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 49836 0 49833 6 5 1 2 0 8 0 vmpool 664 56 0 56 6 6 0 1 0 8 0 kstatmem 264 146 0 124 2 0 2 2 0 8 0 scxspl 216 34442 0 34442 16 15 1 8 0 8 1 plimitpl 152 969 0 953 1 0 1 1 0 8 0 sigapl 424 4627 0 4565 8 0 8 8 0 8 0 futexpl 64 41660 0 41660 2 2 0 1 0 8 0 knotepl 120 58006 0 57928 31 27 4 11 0 8 0 kqueuepl 184 930 0 922 16 15 1 4 0 8 0 pipepl 288 1262 0 1235 18 15 3 7 0 8 0 fdescpl 432 4490 0 4469 4 0 4 4 0 8 0 filepl 120 36400 0 36168 39 30 9 16 0 8 0 lockfpl 104 1260 0 1258 3 2 1 2 0 8 0 lockfspl 48 427 0 425 1 0 1 1 0 8 0 sessionpl 144 54 0 38 1 0 1 1 0 8 0 pgrppl 48 77 0 61 1 0 1 1 0 8 0 ucredpl 104 4250 0 4239 1 0 1 1 0 8 0 zombiepl 144 4570 0 4565 2 1 1 1 0 8 0 processpl 1008 4627 0 4565 10 1 9 9 0 8 0 procpl 696 10669 0 10586 11 2 9 10 0 8 0 sosppl 168 29 0 29 6 6 0 1 0 8 0 sockpl 456 11067 0 11044 207 199 8 33 0 8 5 mcl64k 65536 226 0 226 8 8 0 1 0 8 0 mcl16k 16384 68 0 68 9 9 0 1 0 8 0 mcl12k 12288 173 0 173 8 8 0 1 0 8 0 mcl9k 9216 56 0 56 9 9 0 1 0 8 0 mcl8k 8192 308 0 308 3 2 1 1 0 8 1 mcl4k 4096 468 0 468 2 1 1 1 0 8 1 mcl2k2 2112 25 0 25 13 13 0 1 0 8 0 mcl2k 2048 83206 0 83116 50 37 13 31 0 8 0 mtagpl 96 1252 0 966 17 7 10 13 0 8 0 mbufpl 256 193076 0 192567 281 237 44 85 0 8 1 bufpl 288 10457 0 4063 457 0 457 457 0 8 0 anonpl 24 882579 0 862721 155 35 120 127 0 188 0 amapchunkpl 152 77941 0 76992 49 12 37 37 0 158 0 amappl16 200 9169 0 8601 71 39 32 43 0 8 0 amappl15 192 55 0 53 1 0 1 1 0 8 0 amappl14 184 250 0 237 2 0 2 2 0 8 0 amappl13 176 6 0 5 1 0 1 1 0 8 0 amappl12 168 763 0 759 1 0 1 1 0 8 0 amappl11 160 50 0 40 1 0 1 1 0 8 0 amappl10 152 87 0 75 1 0 1 1 0 8 0 amappl9 144 961 0 960 2 1 1 1 0 8 0 amappl8 136 263 0 198 3 0 3 3 0 8 0 amappl7 128 214 0 190 2 0 2 2 0 8 0 amappl6 120 297 0 285 1 0 1 1 0 8 0 amappl5 112 286 0 280 1 0 1 1 0 8 0 amappl4 104 762 0 738 2 1 1 2 0 8 0 amappl3 96 11969 0 11912 2 0 2 2 0 8 0 amappl2 88 5084 0 5017 3 1 2 3 0 8 0 amappl1 80 100963 0 100258 25 9 16 22 0 8 0 amappl 88 27142 0 26963 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 72 136 0 6 3 0 3 3 0 8 0 uaddrrnd 24 4546 0 4522 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4546 0 4522 1 0 1 1 0 8 0 vmmpekpl 168 38448 0 38391 3 0 3 3 0 8 0 vmmpepl 168 423740 0 421156 216 83 133 156 0 357 7 vmsppl 344 4545 0 4521 3 0 3 3 0 8 0 rwobjpl 24 112106 0 104366 50 2 48 48 0 8 0 pdppl 4096 9098 0 9042 404 348 56 68 0 8 0 pvpl 32 1796553 0 1775783 332 98 234 253 0 265 39 pmappl 216 4545 0 4521 2 0 2 2 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1531 0 747 25 0 25 25 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(ffffffff8272a2bf) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a205b,ffffffff827c6cc6,308,ffffffff826f52b3) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807e54b780) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82cc4328) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82cc4328) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffe2b8) 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(ffffffff8272a2bf) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a205b,ffffffff827c6cc6,308,ffffffff826f52b3) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807e54b780) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82cc4328) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82cc4328) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffe2b8) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7