panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/main/kernel/sys/netinet/if_ether.c", line 716 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *333775 3555 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 __assert(ffffffff821e484e,ffffffff821fae77,2cc,ffffffff8216bb78) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802d9c2468) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff824fe1a8) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffe9e0) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffe9e0) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: 9 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 kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/main/kernel/sys/netinet/if_ether.c", line 716 ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 __assert(ffffffff821e484e,ffffffff821fae77,2cc,ffffffff8216bb78) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd802d9c2468) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff824fe1a8) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffe9e0) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffe9e0) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014811e90 rbx 0xffff800014811f40 rdx 0x2 rcx 0 rax 0 r8 0xffff800014811e50 r9 0x1 r10 0 r11 0x9f77d1c52e6d0538 r12 0x3000000008 r13 0xffff800014811ea0 r14 0x100 r15 0x1 rip 0xffffffff817d7238 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800014811e80 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=333775 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffffeed0,0xffff8000ffffe778 process=0xffff8000ffffca20 user=0xffff80001480d000, vmspace=0xffffffff8256b250 estcpu=1, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 18714 462329 64160 0 2 0 syz-executor.1 18714 412340 64160 0 3 0x4000080 fsleep syz-executor.1 18714 196652 64160 0 2 0x4000000 syz-executor.1 61623 516627 67744 0 3 0x82 piperd syz-executor.0 64160 102124 67744 0 2 0x482 syz-executor.1 77751 454696 0 0 3 0x14200 acct acct 94687 407161 0 0 3 0x14200 bored sosplice 67744 31429 27878 0 3 0x82 thrsleep syz-fuzzer 67744 439727 27878 0 3 0x4000082 thrsleep syz-fuzzer 67744 423621 27878 0 3 0x4000082 thrsleep syz-fuzzer 67744 448367 27878 0 3 0x4000082 thrsleep syz-fuzzer 67744 300795 27878 0 3 0x4000082 thrsleep syz-fuzzer 67744 286186 27878 0 3 0x4000082 kqread syz-fuzzer 67744 129793 27878 0 3 0x4000082 thrsleep syz-fuzzer 27878 335890 67019 0 3 0x10008a pause ksh 67019 247269 35471 0 3 0x92 select sshd 89945 270794 1 0 3 0x100083 ttyin getty 35471 155444 1 0 3 0x80 select sshd 48647 171502 17761 73 3 0x100090 kqread syslogd 17761 460230 1 0 3 0x100082 netio syslogd 75594 336353 0 0 3 0x14200 pgzero zerothread 14006 416185 0 0 3 0x14200 aiodoned aiodoned 83476 195887 0 0 3 0x14200 syncer update 66335 43108 0 0 3 0x14200 cleaner cleaner 44342 310049 0 0 3 0x14200 reaper reaper 57827 125964 0 0 3 0x14200 pgdaemon pagedaemon 12254 23277 0 0 3 0x14200 bored crynlk 36849 115111 0 0 3 0x14200 bored crypto 90151 464797 0 0 3 0x40014200 acpi0 acpi0 83650 430622 0 0 3 0x14200 bored softnet 88712 73359 0 0 3 0x14200 bored systqmp 6858 522481 0 0 3 0x14200 bored systq * 3555 333775 0 0 7 0x40014200 softclock 78250 107271 0 0 3 0x40014200 idle0 79014 463915 0 0 3 0x14200 bored smr 1 295410 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 Kern Lim devbuf 9608 6973K 8026K 78643K 22554 0 0 pcb 13 11K 12K 78643K 1210 0 0 rtable 131 9K 9K 78643K 3570 0 0 ifaddr 104 22K 23K 78643K 994 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 753 0 0 iov 0 0K 32K 78643K 2461 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1225 77K 78K 78643K 6008 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 112 0 0 VM map 49 12K 12K 78643K 81 0 0 sem 12 0K 1K 78643K 1229 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 5 13K 25K 78643K 5945 0 0 sigio 0 0K 0K 78643K 73 0 0 proc 44 30K 55K 78643K 2179 0 0 subproc 32 2K 2K 78643K 648 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 1339 0 0 in_multi 33 2K 2K 78643K 626 0 0 ether_multi 1 0K 0K 78643K 38 0 0 mrt 0 0K 0K 78643K 37 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 132 583K 583K 78643K 132 0 0 exec 0 0K 1K 78643K 1322 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 183 413K 421K 78643K 15590 0 0 UVM aobj 130 4K 4K 78643K 178 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 1K 78643K 1241 0 0 NDP 24 0K 1K 78643K 322 0 0 temp 254 3541K 4181K 78643K 160566 0 0 kqueue 0 0K 0K 78643K 47 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 152 0 143 1 0 1 1 0 8 0 rtpcb 80 1316 0 1316 2 1 1 1 0 8 1 rtentry 112 714 0 663 2 0 2 2 0 8 0 unpcb 120 2795 0 2786 5 4 1 2 0 8 0 syncache 264 24 0 24 9 8 1 1 0 8 1 sackhl 24 5 0 5 4 4 0 1 0 8 0 tcpqe 32 76 0 76 6 6 0 1 0 8 0 tcpcb 544 3402 0 3398 20 19 1 13 0 8 0 ipq 40 42 0 42 16 16 0 1 0 8 0 ipqe 40 788 0 788 16 16 0 1 0 8 0 inpcb 280 7266 0 7262 27 25 2 9 0 8 1 rttmr 72 20 0 19 1 0 1 1 0 8 0 ip6q 72 3 0 3 3 3 0 1 0 8 0 ip6af 40 4 0 4 2 2 0 1 0 8 0 nd6 48 92 0 89 6 5 1 1 0 8 0 pkpcb 40 32 0 32 13 13 0 1 0 8 0 ppxss 1128 110 0 110 23 22 1 1 0 8 1 art_heap8 4096 7 0 6 4 3 1 3 0 8 0 art_heap4 256 2719 0 2462 48 29 19 20 0 8 1 art_table 32 2726 0 2468 3 0 3 3 0 8 0 art_node 16 709 0 664 1 0 1 1 0 8 0 sysvmsgpl 40 32 0 17 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 1227 0 1217 1 0 1 1 0 8 0 shmpl 112 176 0 48 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 10461 0 9059 46 0 46 46 0 8 0 ffsino 240 10461 0 9059 83 0 83 83 0 8 0 nchpl 144 22040 0 21532 60 40 20 60 0 8 0 uvmvnodes 72 8544 0 0 156 0 156 156 0 8 0 vnodes 208 8544 0 0 450 0 450 450 0 8 0 namei 1024 76282 0 76282 4 3 1 1 0 8 1 vcpupl 1984 48 0 1 6 0 6 6 0 8 0 vmpool 520 79 0 32 9 5 4 4 0 8 0 scsiplug 64 14 0 14 7 7 0 1 0 8 0 scxspl 192 68207 0 68207 45 42 3 7 0 8 3 plimitpl 152 496 0 490 1 0 1 1 0 8 0 sigapl 432 6014 0 6003 2 0 2 2 0 8 0 futexpl 56 168006 0 168005 4 3 1 1 0 8 0 knotepl 112 1491 0 1472 1 0 1 1 0 8 0 kqueuepl 104 1613 0 1611 4 3 1 4 0 8 0 pipepl 112 2986 0 2963 9 8 1 2 0 8 0 fdescpl 424 6015 0 6003 2 0 2 2 0 8 0 filepl 120 52832 0 52737 28 24 4 11 0 8 1 lockfpl 104 2272 0 2272 1 0 1 1 0 8 1 lockfspl 48 737 0 737 1 0 1 1 0 8 1 sessionpl 112 51 0 43 1 0 1 1 0 8 0 pgrppl 48 111 0 103 1 0 1 1 0 8 0 ucredpl 96 7010 0 7003 1 0 1 1 0 8 0 zombiepl 144 6009 0 6009 1 0 1 1 0 8 1 processpl 864 6037 0 6009 4 0 4 4 0 8 0 procpl 632 13090 0 13054 4 0 4 4 0 8 0 sosppl 128 61 0 61 15 15 0 1 0 8 0 sockpl 384 11531 0 11518 50 46 4 13 0 8 1 mcl64k 65536 1220 0 1220 98 92 6 33 0 8 6 mcl16k 16384 60 0 60 23 22 1 1 0 8 1 mcl12k 12288 160 0 160 12 11 1 1 0 8 1 mcl9k 9216 98 0 98 22 21 1 1 0 8 1 mcl8k 8192 262 0 262 10 9 1 1 0 8 1 mcl4k 4096 604 0 604 5 4 1 1 0 8 1 mcl2k2 2112 59 0 59 21 20 1 1 0 8 1 mcl2k 2048 74613 0 74567 19 12 7 15 0 8 0 mtagpl 80 281 0 264 7 6 1 1 0 8 0 mbufpl 256 169280 0 169152 156 141 15 33 0 8 5 bufpl 256 31269 0 22720 535 0 535 535 0 8 0 anonpl 16 733094 0 717846 244 159 85 96 0 62 4 amapchunkpl 152 31970 0 31852 82 76 6 16 0 158 0 amappl16 192 34146 0 33040 249 186 63 69 0 8 6 amappl15 184 1194 0 1193 1 0 1 1 0 8 0 amappl14 176 1289 0 1285 1 0 1 1 0 8 0 amappl13 168 847 0 847 8 8 0 1 0 8 0 amappl12 160 1171 0 1167 1 0 1 1 0 8 0 amappl11 152 364 0 357 1 0 1 1 0 8 0 amappl10 144 623 0 621 1 0 1 1 0 8 0 amappl9 136 1908 0 1902 1 0 1 1 0 8 0 amappl8 128 1446 0 1401 2 0 2 2 0 8 0 amappl7 120 766 0 760 1 0 1 1 0 8 0 amappl6 112 286 0 273 1 0 1 1 0 8 0 amappl5 104 1619 0 1611 1 0 1 1 0 8 0 amappl4 96 5680 0 5654 1 0 1 1 0 8 0 amappl3 88 2062 0 2056 1 0 1 1 0 8 0 amappl2 80 46207 0 46137 3 1 2 3 0 8 0 amappl1 72 121014 0 120627 26 16 10 20 0 8 0 amappl 80 13937 0 13877 2 0 2 2 0 84 0 dma4096 4096 1 0 1 1 1 0 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 17 0 17 1 1 0 1 0 8 0 aobjpl 64 177 0 48 3 0 3 3 0 8 0 uaddrrnd 24 6094 0 6003 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 6094 0 6003 1 0 1 1 0 8 0 vmmpekpl 168 39786 0 39749 2 0 2 2 0 8 0 vmmpepl 168 734133 0 731880 414 275 139 143 0 357 31 vmsppl 272 6014 0 6003 3 2 1 2 0 8 0 pdppl 4096 12194 0 12117 13 3 10 11 0 8 0 pvpl 32 1966541 0 1949295 539 341 198 315 0 265 18 pmappl 200 6093 0 6035 5 1 4 4 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 1026 0 341 21 0 21 21 0 8 0