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 *239947 90059 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82781d73) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff827fbf28,ffffffff8281fcc8,2f6,ffffffff8274ca2a) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd80677034e8) at arptfree+0x131 sys/netinet/if_ether.c:758 arptimer(ffffffff82cb6900) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82cb6900) at timeout_run+0x8f sys/kern/kern_timeout.c:640 softclock_thread(ffff8000215ea298) at softclock_thread+0xd4 sys/kern/kern_timeout.c:763 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(ffffffff82781d73) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff827fbf28,ffffffff8281fcc8,2f6,ffffffff8274ca2a) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd80677034e8) at arptfree+0x131 sys/netinet/if_ether.c:758 arptimer(ffffffff82cb6900) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82cb6900) at timeout_run+0x8f sys/kern/kern_timeout.c:640 softclock_thread(ffff8000215ea298) at softclock_thread+0xd4 sys/kern/kern_timeout.c:763 end trace frame: 0x0, count: -7 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff8000215f62a0 rbx 0 rdx 0 rcx 0 rax 0xffff8000215ea298 r8 0x101010101010101 r9 0x8080808080808080 r10 0xdc92980510b993da r11 0xaa2bd63a684b4718 r12 0 r13 0xfffffd806ec79580 r14 0 r15 0x1 rip 0xffffffff81877d4c db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff8000215f6290 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb> show proc PROC (softclock) tid=239947 pid=90059 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=0xffff8000215ea540,0xffff8000215ea000 process=0xffff8000ffffe7e0 user=0xffff8000215f1000, vmspace=0xffffffff82c802b0 estcpu=0, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 16032 37591 1308 0 4 0x82000 syz-executor.1 16032 272797 1308 0 3 0x4002000 suspend syz-executor.1 16032 78747 1308 0 4 0x4082000 syz-executor.1 16032 518768 1308 0 3 0x4082000 clonelk syz-executor.1 13868 262449 41512 0 3 0x82 piperd syz-executor.6 35185 355914 41512 0 3 0x82 piperd syz-executor.4 72625 413371 0 0 3 0x14280 nfsidl nfsio 55426 452499 0 0 3 0x14280 nfsidl nfsio 49461 465986 0 0 3 0x14280 nfsidl nfsio 44546 307136 0 0 3 0x14280 nfsidl nfsio 34066 436969 0 0 3 0x14280 nfsidl nfsio 39449 40836 0 0 3 0x14280 nfsidl nfsio 59567 483327 0 0 3 0x14280 nfsidl nfsio 78618 162116 0 0 3 0x14280 nfsidl nfsio 75426 256913 0 0 3 0x14280 nfsidl nfsio 22529 55906 0 0 3 0x14280 nfsidl nfsio 33604 477043 0 0 3 0x14280 nfsidl nfsio 33317 196371 0 0 3 0x14280 nfsidl nfsio 45794 265274 0 0 3 0x14280 nfsidl nfsio 25433 85462 0 0 3 0x14280 nfsidl nfsio 15944 292926 0 0 3 0x14280 nfsidl nfsio 68011 412938 0 0 3 0x14280 nfsidl nfsio 18302 464812 0 0 3 0x14280 nfsidl nfsio 32530 521295 0 0 3 0x14280 nfsidl nfsio 26308 125869 0 0 3 0x14280 nfsidl nfsio 45292 422103 0 0 3 0x14280 nfsidl nfsio 35119 140544 41512 0 3 0x82 piperd syz-executor.5 75986 110250 1 0 3 0x100083 ttyin getty 1308 475511 41512 0 2 0x482 syz-executor.1 66625 146319 0 0 3 0x14200 bored sosplice 41512 49099 59498 0 3 0x2000082 wait syz-fuzzer 41512 75190 59498 0 2 0x6000482 syz-fuzzer 41512 508402 59498 0 3 0x6000082 thrsleep syz-fuzzer 41512 359315 59498 0 3 0x6000082 thrsleep syz-fuzzer 41512 100785 59498 0 3 0x6000082 thrsleep syz-fuzzer 41512 236221 59498 0 3 0x6000082 wait syz-fuzzer 41512 19331 59498 0 3 0x6000082 wait syz-fuzzer 41512 27728 59498 0 3 0x6000082 thrsleep syz-fuzzer 41512 496524 59498 0 3 0x6000082 thrsleep syz-fuzzer 41512 380348 59498 0 3 0x6000082 thrsleep syz-fuzzer 41512 79782 59498 0 3 0x6000082 wait syz-fuzzer 41512 107521 59498 0 3 0x6000082 wait syz-fuzzer 41512 357338 59498 0 3 0x6000082 kqread syz-fuzzer 41512 397984 59498 0 3 0x6000082 wait syz-fuzzer 41512 317040 59498 0 3 0x6000082 thrsleep syz-fuzzer 59498 61624 57404 0 3 0x10008a sigsusp ksh 57404 121155 79714 0 3 0x9a kqread sshd 79714 93592 1 0 3 0x88 kqread sshd 61680 431883 96655 73 2 0x1100010 syslogd 96655 504140 1 0 3 0x100082 netio syslogd 37047 521974 1 0 3 0x100080 kqread resolvd 13013 295997 14298 77 3 0x100092 kqread dhcpleased 65326 29424 14298 77 3 0x100092 kqread dhcpleased 14298 132906 1 0 3 0x80 kqread dhcpleased 47706 510045 0 0 3 0x14200 bored smr 90887 32537 0 0 3 0x14200 pgzero zerothread 35312 154978 0 0 3 0x14200 aiodoned aiodoned 16486 403318 0 0 3 0x14200 syncer update 50575 399987 0 0 3 0x14200 cleaner cleaner 91698 469652 0 0 3 0x14200 reaper reaper 91914 178899 0 0 3 0x14200 pgdaemon pagedaemon 88299 88898 0 0 3 0x14200 bored viomb 8133 473849 0 0 3 0x40014200 acpi0 acpi0 97017 240097 0 0 3 0x14200 bored softnet3 43792 398995 0 0 3 0x14200 bored softnet2 9734 341812 0 0 3 0x14200 bored softnet1 94475 341058 0 0 3 0x14200 bored softnet0 102 92117 0 0 3 0x14200 bored systqmp 37161 324618 0 0 3 0x14200 bored systq *90059 239947 0 0 7 0x40014200 softclock 79673 81728 0 0 3 0x40014200 idle0 1 517750 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 10189 6430K 8114K 78643K 49348 0 pcb 13 18K 20K 78643K 973 0 rtable 201 6K 7K 78643K 1439 0 pf 30 9K 10K 78643K 253 0 ifaddr 37 10K 13K 78643K 230 0 ifgroup 51 2K 2K 78643K 422 0 sysctl 3 0K 2K 78643K 11 0 counters 28 17K 17K 78643K 132 0 ioctlops 0 0K 2K 78643K 485 0 iov 0 0K 20K 78643K 1241 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1704 107K 107K 78643K 11923 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 149 0 VM map 2 1K 1K 78643K 2 0 sem 10 1K 1K 78643K 19 0 dirhash 6 1K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 9 29K 69K 78643K 12183 0 sigio 0 0K 0K 78643K 272 0 proc 58 59K 83K 78643K 1763 0 subproc 78 4K 10K 78643K 632 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 520 0 in_multi 77 5K 7K 78643K 442 0 ether_multi 1 0K 0K 78643K 11 0 mrt 1 0K 0K 78643K 8 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 145 652K 652K 78643K 145 0 exec 0 0K 1K 78643K 2887 0 pfkey data 0 0K 0K 78643K 43 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 377 82K 115K 78643K 114629 0 UVM aobj 131 7K 7K 78643K 147 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 465 0 NDP 11 0K 2K 78643K 181 0 temp 66 5911K 6040K 78643K 157157 0 kqueue 12 18K 26K 78643K 769 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 120 613 0 610 9 8 1 3 0 8 0 rtentry 112 414 0 322 4 0 4 4 0 8 0 unpcb 144 29420 0 29407 157 156 1 12 0 8 0 syncache 304 148 0 148 27 27 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 157 190 157 17 17 0 1 0 8 0 tcpcb 808 3607 0 3575 110 103 7 16 0 8 3 arp 88 71 0 56 1 0 1 1 0 8 0 ipq 40 11 0 11 7 7 0 1 0 8 0 ipqe 40 103 0 103 7 7 0 1 0 8 0 inpcb 336 9126 0 9091 140 131 9 15 0 8 5 nd6 104 113 0 92 1 0 1 1 0 8 0 pkpcb 40 38 0 38 8 8 0 1 0 8 0 kcovpl 48 33 0 27 1 0 1 1 0 8 0 ppxss 1160 30 0 30 9 9 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1606 0 1225 38 8 30 30 0 8 1 art_table 32 1607 0 1225 4 0 4 4 0 8 0 art_node 16 402 0 318 1 0 1 1 0 8 0 semupl 112 7 0 7 1 1 0 1 0 8 0 semapl 112 8 0 0 1 0 1 1 0 8 0 shmpl 112 144 0 16 4 0 4 4 0 8 0 dirhash 1024 17 0 13 3 1 2 3 0 8 0 dino2pl 256 17908 0 16380 97 0 97 97 0 8 0 ffsino 240 17908 0 16380 91 0 91 91 0 8 0 nchpl 144 35411 0 34936 63 41 22 63 0 8 0 uvmvnodes 80 6480 0 0 133 0 133 133 0 8 0 vnodes 216 6480 0 0 360 0 360 360 0 8 0 namei 1024 123758 0 123758 9 8 1 2 0 8 1 vmpool 664 149 0 149 24 23 1 1 0 8 1 kstatmem 264 230 0 208 3 1 2 3 0 8 0 scxspl 216 116515 0 116515 26 25 1 8 1 8 1 plimitpl 152 1034 0 1021 1 0 1 1 0 8 0 sigapl 424 12692 0 12633 9 1 8 8 0 8 0 futexpl 64 127516 0 127516 8 7 1 1 0 8 1 knotepl 120 133075 0 133011 52 49 3 11 0 8 0 kqueuepl 184 1739 0 1730 21 20 1 4 0 8 0 pipepl 288 2897 0 2877 65 62 3 10 0 8 0 fdescpl 432 12414 0 12394 5 1 4 4 0 8 0 filepl 120 99833 0 99643 156 147 9 20 0 8 1 lockfpl 104 11494 0 11492 19 18 1 4 0 8 0 lockfspl 48 4952 0 4950 3 2 1 2 0 8 0 sessionpl 144 51 0 37 1 0 1 1 0 8 0 pgrppl 48 417 0 403 1 0 1 1 0 8 0 ucredpl 104 10244 0 10233 1 0 1 1 0 8 0 zombiepl 144 12637 0 12633 1 0 1 1 0 8 0 processpl 1008 12692 0 12633 12 3 9 9 0 8 0 procpl 680 31170 0 31094 26 18 8 9 0 8 0 sosppl 168 190 0 190 7 7 0 1 0 8 0 sockpl 456 39203 0 39152 825 810 15 42 0 8 7 mcl64k 65536 563 0 563 20 20 0 1 0 8 0 mcl16k 16384 225 0 225 22 22 0 1 0 8 0 mcl12k 12288 496 0 496 18 18 0 1 0 8 0 mcl9k 9216 185 0 185 25 25 0 1 0 8 0 mcl8k 8192 828 0 828 20 20 0 1 0 8 0 mcl4k 4096 1636 0 1636 17 16 1 1 0 8 1 mcl2k2 2112 76 0 76 27 27 0 1 0 8 0 mcl2k 2048 91436 0 91394 64 56 8 30 0 8 1 mtagpl 96 4860 0 4577 26 16 10 20 0 8 0 mbufpl 256 345069 0 344694 1706 1657 49 212 0 8 1 bufpl 288 26370 0 19889 464 0 464 464 0 8 0 anonpl 24 1221691 0 1210699 195 81 114 114 0 188 12 amapchunkpl 152 375314 0 374599 120 76 44 50 0 158 7 amappl16 200 24758 0 24367 87 61 26 34 0 8 0 amappl15 192 15 0 15 2 2 0 1 0 8 0 amappl14 184 233 0 218 2 1 1 2 0 8 0 amappl13 176 12 0 12 1 1 0 1 0 8 0 amappl12 168 13415 0 13395 2 0 2 2 0 8 0 amappl11 160 48 0 38 1 0 1 1 0 8 0 amappl10 152 50 0 43 2 1 1 1 0 8 0 amappl9 144 231 0 229 1 0 1 1 0 8 0 amappl8 136 605 0 480 5 0 5 5 0 8 0 amappl7 128 114 0 98 2 0 2 2 0 8 0 amappl6 120 455 0 426 2 1 1 2 0 8 0 amappl5 112 486 0 477 1 0 1 1 0 8 0 amappl4 104 884 0 849 3 2 1 2 0 8 0 amappl3 96 72246 0 72189 3 0 3 3 0 8 0 amappl2 88 13008 0 12949 3 1 2 3 0 8 0 amappl1 80 54781 0 54293 23 12 11 22 0 8 0 amappl 88 113602 0 113406 7 0 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 72 146 0 16 3 0 3 3 0 8 0 uaddrrnd 24 12563 0 12543 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 12563 0 12543 1 0 1 1 0 8 0 vmmpekpl 168 91977 0 91918 3 0 3 3 0 8 0 vmmpepl 168 738395 0 736430 290 176 114 128 0 357 0 vmsppl 368 12562 0 12543 3 0 3 3 0 8 0 rwobjpl 24 178137 0 170127 54 4 50 50 0 8 0 pdppl 4096 25132 0 25086 541 485 56 66 0 8 10 pvpl 32 3410099 0 3394052 581 361 220 358 0 265 45 pmappl 216 12562 0 12543 2 0 2 2 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 3440 0 2609 31 4 27 29 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(ffffffff82781d73) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff827fbf28,ffffffff8281fcc8,2f6,ffffffff8274ca2a) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd80677034e8) at arptfree+0x131 sys/netinet/if_ether.c:758 arptimer(ffffffff82cb6900) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82cb6900) at timeout_run+0x8f sys/kern/kern_timeout.c:640 softclock_thread(ffff8000215ea298) at softclock_thread+0xd4 sys/kern/kern_timeout.c:763 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(ffffffff82781d73) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff827fbf28,ffffffff8281fcc8,2f6,ffffffff8274ca2a) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd80677034e8) at arptfree+0x131 sys/netinet/if_ether.c:758 arptimer(ffffffff82cb6900) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82cb6900) at timeout_run+0x8f sys/kern/kern_timeout.c:640 softclock_thread(ffff8000215ea298) at softclock_thread+0xd4 sys/kern/kern_timeout.c:763 end trace frame: 0x0, count: -7