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 *138393 92652 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8272591e) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a2089,ffffffff827c4bac,308,ffffffff826f4fdb) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8079e54b08) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82c371f8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c371f8) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffed98) 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(ffffffff8272591e) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a2089,ffffffff827c4bac,308,ffffffff826f4fdb) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8079e54b08) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82c371f8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c371f8) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffed98) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800021604b30 rbx 0 rdx 0 rcx 0 rax 0xffff8000ffffed98 r8 0x101010101010101 r9 0x8080808080808080 r10 0x112d89767d152409 r11 0xd4a5d57bee559697 r12 0 r13 0xfffffd8077532840 r14 0 r15 0x1 rip 0xffffffff8167da08 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021604b20 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=138393 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff5c0,0xffff8000ffffeaf0 process=0xffff8000ffffc000 user=0xffff8000215ff000, vmspace=0xffffffff82be92a0 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 24197 8647 35171 0 2 0 syz-executor.3 79530 163581 49468 0 2 0 syz-executor.7 75592 517045 87633 0 2 0 syz-executor.2 57921 403513 50811 0 2 0 syz-executor.6 82657 429222 81620 0 2 0 syz-executor.1 82757 11052 44138 0 2 0 syz-executor.4 82757 432561 44138 0 2 0x4000000 syz-executor.4 57110 396844 82586 0 2 0 syz-executor.5 57110 427296 82586 0 2 0x4000000 syz-executor.5 81620 402440 37126 0 2 0x482 syz-executor.1 44138 325028 37126 0 2 0x482 syz-executor.4 49468 449565 37126 0 2 0x482 syz-executor.7 87633 255248 37126 0 2 0x2 syz-executor.2 82586 79087 37126 0 2 0x482 syz-executor.5 5491 133724 1 0 3 0x100083 ttyin getty 35171 250341 37126 0 2 0x482 syz-executor.3 61256 28111 0 0 3 0x14280 nfsidl nfsio 82764 398147 0 0 3 0x14280 nfsidl nfsio 45947 337953 0 0 3 0x14280 nfsidl nfsio 97990 118117 0 0 3 0x14280 nfsidl nfsio 64915 502964 0 0 3 0x14280 nfsidl nfsio 53511 48431 0 0 3 0x14280 nfsidl nfsio 66067 155478 0 0 3 0x14280 nfsidl nfsio 76488 66863 0 0 3 0x14280 nfsidl nfsio 61754 88690 0 0 3 0x14280 nfsidl nfsio 99477 372572 0 0 3 0x14280 nfsidl nfsio 33001 219439 0 0 3 0x14280 nfsidl nfsio 30505 180756 0 0 3 0x14280 nfsidl nfsio 30470 47484 0 0 3 0x14280 nfsidl nfsio 20969 197089 0 0 3 0x14280 nfsidl nfsio 41446 290837 0 0 3 0x14280 nfsidl nfsio 33120 384675 0 0 3 0x14280 nfsidl nfsio 11112 54584 0 0 3 0x14280 nfsidl nfsio 50555 349091 0 0 3 0x14280 nfsidl nfsio 80938 39388 0 0 3 0x14280 nfsidl nfsio 72542 234653 0 0 3 0x14280 nfsidl nfsio 49761 241572 0 0 3 0x14200 bored sosplice 50811 480809 37126 0 2 0x2 syz-executor.6 37126 431136 69639 0 3 0x82 thrsleep syz-fuzzer 37126 255767 69639 0 2 0x4000482 syz-fuzzer 37126 324779 69639 0 3 0x4000082 thrsleep syz-fuzzer 37126 5233 69639 0 3 0x4000082 wait syz-fuzzer 37126 426974 69639 0 3 0x4000082 thrsleep syz-fuzzer 37126 51114 69639 0 3 0x4000082 kqread syz-fuzzer 37126 83125 69639 0 3 0x4000082 wait syz-fuzzer 37126 409422 69639 0 3 0x4000082 thrsleep syz-fuzzer 37126 299684 69639 0 3 0x4000082 wait syz-fuzzer 37126 394060 69639 0 3 0x4000082 wait syz-fuzzer 37126 133428 69639 0 3 0x4000082 wait syz-fuzzer 37126 197750 69639 0 3 0x4000082 wait syz-fuzzer 37126 192626 69639 0 3 0x4000082 thrsleep syz-fuzzer 37126 449593 69639 0 3 0x4000082 wait syz-fuzzer 69639 145944 41645 0 3 0x10008a sigsusp ksh 41645 55664 66423 0 3 0x9a kqread sshd 66423 69458 1 0 3 0x88 kqread sshd 85352 41841 28696 73 3 0x1100090 kqread syslogd 28696 298565 1 0 3 0x100082 netio syslogd 11501 447723 1 0 3 0x100080 kqread resolvd 29129 206880 18547 77 3 0x100092 kqread dhcpleased 16357 333409 18547 77 3 0x100092 kqread dhcpleased 18547 395292 1 0 3 0x80 kqread dhcpleased 15001 437841 0 0 2 0x14200 smr 5682 240095 0 0 2 0x14200 zerothread 12378 279073 0 0 3 0x14200 aiodoned aiodoned 95354 142522 0 0 3 0x14200 syncer update 49457 421995 0 0 3 0x14200 cleaner cleaner 514 473484 0 0 3 0x14200 reaper reaper 80258 159393 0 0 3 0x14200 pgdaemon pagedaemon 94626 55516 0 0 3 0x14200 bored viomb 75325 372904 0 0 3 0x40014200 acpi0 acpi0 15878 414320 0 0 3 0x14200 bored softnet 23971 126517 0 0 3 0x14200 bored softnet 38076 162331 0 0 3 0x14200 bored softnet 77874 395065 0 0 2 0x14200 softnet 92601 29765 0 0 3 0x14200 bored systqmp 25806 379221 0 0 3 0x14200 bored systq *92652 138393 0 0 7 0x40014200 softclock 97353 334719 0 0 3 0x40014200 idle0 1 327781 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 10215 6430K 6875K 78643K 22109 0 pcb 13 18K 22K 78643K 1502 0 rtable 173 14K 15K 78643K 1709 0 ifaddr 67 20K 21K 78643K 434 0 sysctl 2 0K 1K 78643K 6 0 counters 26 17K 17K 78643K 131 0 ioctlops 0 0K 4K 78643K 686 0 iov 0 0K 16K 78643K 774 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1636 102K 103K 78643K 8531 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 58 0 VM map 2 0K 0K 78643K 2 0 sem 14 2K 3K 78643K 399 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 17 61K 77K 78643K 4523 0 sigio 0 0K 0K 78643K 101 0 proc 58 59K 75K 78643K 1282 0 subproc 104 6K 6K 78643K 390 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 290 0 in_multi 70 4K 6K 78643K 464 0 ether_multi 1 0K 0K 78643K 18 0 mrt 1 0K 0K 78643K 25 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 169 758K 758K 78643K 169 0 exec 0 0K 1K 78643K 1626 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 289 87K 98K 78643K 29962 0 UVM aobj 131 4K 4K 78643K 134 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 194 0 NDP 11 0K 1K 78643K 157 0 temp 124 5770K 6794K 78643K 77001 0 kqueue 12 18K 26K 78643K 414 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 120 472 0 469 9 8 1 3 0 8 0 rtentry 112 553 0 480 4 1 3 4 0 8 0 unpcb 144 6065 0 6052 47 46 1 11 0 8 0 syncache 296 48 0 48 8 7 1 1 0 8 1 tcpqe 32 243 0 243 7 7 0 1 0 8 0 tcpcb 776 2980 0 2976 74 66 8 11 0 8 7 arp 88 67 0 55 1 0 1 1 0 8 0 inpcb 336 6671 0 6664 83 76 7 18 0 8 6 nd6 48 102 0 86 1 0 1 1 0 8 0 pkpcb 40 78 0 78 3 3 0 1 0 8 0 kcovpl 48 30 0 22 1 0 1 1 0 8 0 ppxss 1160 56 0 56 9 9 0 1 0 8 0 pppxif 1360 19 0 19 5 5 0 1 0 8 0 pfstscr 40 43 0 34 1 0 1 1 0 8 0 pfosfp 40 75 0 72 1 0 1 1 0 8 0 pfosfpen 112 75 0 70 1 0 1 1 0 8 0 pfanchor 1280 732 36 220 46 3 43 43 0 8 0 pfqueue 264 2 0 2 1 1 0 1 0 8 0 pfstitem 24 10 0 6 1 0 1 1 0 8 0 pfstkey 128 78 0 71 1 0 1 1 0 8 0 pfstate 352 39 0 34 1 0 1 1 0 8 0 rttmr 136 6 0 6 2 2 0 1 0 8 0 art_heap8 4096 6 0 4 5 3 2 3 0 8 0 art_heap4 256 2540 0 2196 40 15 25 29 0 8 0 art_table 32 2546 0 2200 5 1 4 4 0 8 0 art_node 16 515 0 452 1 0 1 1 0 8 0 sysvmsgpl 40 12 0 6 1 0 1 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 390 0 378 1 0 1 1 0 8 0 shmpl 112 131 0 3 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 7508 0 6062 91 0 91 91 0 8 0 ffsino 240 7508 0 6062 86 0 86 86 0 8 0 nchpl 144 13416 0 11794 63 0 63 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 54969 0 54969 2 1 1 2 0 8 1 vmpool 664 17 0 17 2 2 0 1 0 8 0 kstatmem 264 174 0 152 2 0 2 2 0 8 0 scxspl 216 36366 0 36366 13 12 1 8 0 8 1 plimitpl 152 472 0 457 1 0 1 1 0 8 0 sigapl 424 4796 0 4731 8 0 8 8 0 8 0 futexpl 64 45872 0 45872 1 0 1 1 0 8 1 knotepl 120 73753 0 73678 25 18 7 9 0 8 2 kqueuepl 184 925 0 917 18 17 1 6 0 8 0 pipepl 288 1598 0 1573 35 32 3 11 0 8 0 fdescpl 432 4759 0 4731 4 0 4 4 0 8 0 filepl 120 43222 0 42994 64 50 14 17 0 8 4 lockfpl 104 1030 0 1028 3 1 2 2 0 8 1 lockfspl 48 413 0 411 1 0 1 1 0 8 0 sessionpl 144 48 0 32 1 0 1 1 0 8 0 pgrppl 48 124 0 108 1 0 1 1 0 8 0 ucredpl 104 5360 0 5348 1 0 1 1 0 8 0 zombiepl 144 4732 0 4731 1 0 1 1 0 8 0 processpl 1008 4796 0 4731 11 2 9 9 0 8 0 procpl 696 11354 0 11274 14 4 10 10 0 8 0 sosppl 168 62 0 62 6 6 0 1 0 8 0 sockpl 456 13286 0 13263 285 274 11 36 0 8 8 mcl64k 65536 182 0 182 9 8 1 1 0 8 1 mcl16k 16384 96 0 96 12 11 1 1 0 8 1 mcl12k 12288 191 0 191 7 6 1 1 0 8 1 mcl9k 9216 53 0 53 12 12 0 1 0 8 0 mcl8k 8192 288 0 288 6 5 1 1 0 8 1 mcl4k 4096 528 0 528 2 1 1 1 0 8 1 mcl2k2 2112 110 0 110 11 10 1 1 0 8 1 mcl2k 2048 86588 0 86509 45 33 12 31 0 8 0 mtagpl 96 688 0 514 10 5 5 5 0 8 0 mbufpl 256 186014 0 185671 670 643 27 430 0 8 0 bufpl 288 10153 0 3756 458 0 458 458 0 8 0 anonpl 24 968399 0 953933 146 28 118 131 0 188 0 amapchunkpl 152 82661 0 82015 48 18 30 36 0 158 0 amappl16 200 12049 0 11469 92 60 32 44 0 8 0 amappl15 192 8 0 7 1 0 1 1 0 8 0 amappl14 184 246 0 234 2 1 1 2 0 8 0 amappl13 176 6 0 5 1 0 1 1 0 8 0 amappl12 168 673 0 666 1 0 1 1 0 8 0 amappl11 160 42 0 32 1 0 1 1 0 8 0 amappl10 152 57 0 48 1 0 1 1 0 8 0 amappl9 144 967 0 966 1 0 1 1 0 8 0 amappl8 136 284 0 221 4 1 3 3 0 8 0 amappl7 128 205 0 180 2 0 2 2 0 8 0 amappl6 120 250 0 239 1 0 1 1 0 8 0 amappl5 112 258 0 252 1 0 1 1 0 8 0 amappl4 104 747 0 718 2 1 1 2 0 8 0 amappl3 96 12846 0 12802 2 0 2 2 0 8 0 amappl2 88 5335 0 5269 3 1 2 3 0 8 0 amappl1 80 107129 0 106477 25 9 16 22 0 8 0 amappl 88 29166 0 29007 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 72 133 0 3 3 0 3 3 0 8 0 uaddrrnd 24 4776 0 4748 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4776 0 4748 1 0 1 1 0 8 0 vmmpekpl 168 40902 0 40845 3 0 3 3 0 8 0 vmmpepl 168 444660 0 442015 249 121 128 168 0 357 3 vmsppl 272 4775 0 4748 4 2 2 3 0 8 0 rwobjpl 24 120397 0 112711 49 0 49 49 0 8 0 pdppl 4096 9558 0 9496 328 266 62 70 0 8 0 pvpl 32 1897429 0 1878087 300 104 196 269 0 265 0 pmappl 216 4775 0 4748 2 0 2 2 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1887 0 1103 35 11 24 35 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(ffffffff8272591e) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a2089,ffffffff827c4bac,308,ffffffff826f4fdb) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8079e54b08) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82c371f8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c371f8) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffed98) 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(ffffffff8272591e) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a2089,ffffffff827c4bac,308,ffffffff826f4fdb) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8079e54b08) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82c371f8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c371f8) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000ffffed98) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7