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 *256246 13848 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(ffffffff821e6642,ffffffff821fe30e,2cc,ffffffff8216f095) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd8038e852a8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff8252f348) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffec58) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffec58) 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(ffffffff821e6642,ffffffff821fe30e,2cc,ffffffff8216f095) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd8038e852a8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff8252f348) at arptimer+0x95 sys/netinet/if_ether.c:120 softclock_thread(ffff8000ffffec58) at softclock_thread+0x145 timeout_run sys/kern/kern_timeout.c:475 [inline] softclock_thread(ffff8000ffffec58) at softclock_thread+0x145 sys/kern/kern_timeout.c:552 end trace frame: 0x0, count: -6 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014811e20 rbx 0xffff800014811ed0 rdx 0x2 rcx 0 rax 0 r8 0xffff800014811de0 r9 0x1 r10 0 r11 0x55133aba0ba59d5e r12 0x3000000008 r13 0xffff800014811e30 r14 0x100 r15 0x1 rip 0xffffffff81939468 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800014811e10 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=256246 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff3c0,0xffff8000ffffe9f0 process=0xffff8000ffffca20 user=0xffff80001480d000, vmspace=0xffffffff82571ae8 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 11492 513155 63690 0 2 0x480 syz-executor.1 11492 357613 63690 0 3 0x4000080 piperd syz-executor.1 11492 420643 63690 0 3 0x4000080 fsleep syz-executor.1 23086 472426 20068 0 2 0x480 syz-executor.0 23086 187631 20068 0 3 0x4000080 poll syz-executor.0 23086 308222 20068 0 3 0x4000080 fsleep syz-executor.0 63690 39433 65118 0 2 0x482 syz-executor.1 20068 315367 65118 0 2 0x482 syz-executor.0 2503 98294 1 0 3 0x100083 ttyin getty 62958 254548 0 0 3 0x14200 acct acct 80472 37985 0 0 3 0x14200 bored sosplice 65118 78587 91908 0 3 0x82 thrsleep syz-fuzzer 65118 350591 91908 0 3 0x4000082 thrsleep syz-fuzzer 65118 161246 91908 0 3 0x4000082 thrsleep syz-fuzzer 65118 119372 91908 0 3 0x4000082 thrsleep syz-fuzzer 65118 407222 91908 0 3 0x4000082 thrsleep syz-fuzzer 65118 89072 91908 0 3 0x4000082 thrsleep syz-fuzzer 65118 287183 91908 0 3 0x4000082 thrsleep syz-fuzzer 65118 22846 91908 0 3 0x4000082 kqread syz-fuzzer 91908 374486 37254 0 3 0x10008a pause ksh 37254 50493 89636 0 3 0x92 select sshd 89636 253164 1 0 3 0x80 select sshd 28709 507017 56951 73 3 0x100090 kqread syslogd 56951 356074 1 0 3 0x100082 netio syslogd 62096 495420 1 77 3 0x100090 poll dhclient 30536 458702 1 0 3 0x80 poll dhclient 54512 305864 0 0 3 0x14200 pgzero zerothread 37643 302132 0 0 3 0x14200 aiodoned aiodoned 54662 220220 0 0 3 0x14200 syncer update 17947 199760 0 0 3 0x14200 cleaner cleaner 34057 9494 0 0 3 0x14200 reaper reaper 36939 252764 0 0 3 0x14200 pgdaemon pagedaemon 64887 118298 0 0 3 0x14200 bored crynlk 68802 412421 0 0 3 0x14200 bored crypto 21268 25552 0 0 3 0x40014200 acpi0 acpi0 62712 212015 0 0 3 0x14200 bored softnet 33941 260781 0 0 3 0x14200 bored systqmp 38524 146548 0 0 3 0x14200 bored systq *13848 256246 0 0 7 0x40014200 softclock 61254 374659 0 0 3 0x40014200 idle0 13696 184764 0 0 3 0x14200 bored smr 1 137947 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 9587 7016K 7591K 78643K 19811 0 0 pcb 13 12K 14K 78643K 964 0 0 rtable 114 12K 13K 78643K 2859 0 0 ifaddr 92 20K 20K 78643K 758 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 254 0 0 iov 0 0K 36K 78643K 1644 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1212 76K 77K 78643K 4818 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 58 0 0 VM map 44 11K 11K 78643K 64 0 0 sem 12 0K 1K 78643K 934 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1793 195K 288K 78643K 12645 0 0 file desc 6 17K 25K 78643K 3851 0 0 sigio 0 0K 0K 78643K 56 0 0 proc 49 38K 63K 78643K 1766 0 0 subproc 32 2K 2K 78643K 459 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 326 0 0 in_multi 25 1K 2K 78643K 558 0 0 ether_multi 1 0K 0K 78643K 30 0 0 mrt 0 0K 0K 78643K 13 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 90 397K 397K 78643K 90 0 0 exec 0 0K 1K 78643K 936 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 175 356K 358K 78643K 11178 0 0 UVM aobj 130 7K 7K 78643K 138 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 712 0 0 NDP 23 0K 1K 78643K 256 0 0 temp 249 3545K 4185K 78643K 104526 0 0 kqueue 0 0K 0K 78643K 34 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 64 107 0 101 1 0 1 1 0 8 0 rtpcb 80 504 0 502 1 0 1 1 0 8 0 rtentry 112 540 0 502 2 0 2 2 0 8 0 unpcb 120 2134 0 2117 4 3 1 2 0 8 0 syncache 264 23 0 23 9 8 1 1 0 8 1 tcpqe 32 95 0 95 4 3 1 1 0 8 1 tcpcb 544 1778 0 1774 27 26 1 14 0 8 0 ipq 40 45 0 45 17 17 0 1 0 8 0 ipqe 40 1013 0 1013 17 17 0 1 0 8 0 inpcb 280 5134 0 5127 54 52 2 13 0 8 1 rttmr 72 1 0 1 1 1 0 1 0 8 0 ip6q 72 3 0 3 2 2 0 1 0 8 0 ip6af 40 9 0 9 2 2 0 1 0 8 0 nd6 48 79 0 77 2 1 1 1 0 8 0 pkpcb 40 14 0 14 5 5 0 1 0 8 0 swfcl 56 2 0 0 1 0 1 1 0 8 0 ppxss 1128 97 0 97 26 25 1 1 0 8 1 art_heap8 4096 9 0 8 7 4 3 3 0 8 2 art_heap4 256 2265 0 2084 28 16 12 15 0 8 0 art_table 32 2274 0 2092 2 0 2 2 0 8 0 art_node 16 537 0 502 1 0 1 1 0 8 0 sysvmsgpl 40 40 0 20 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 932 0 922 1 0 1 1 0 8 0 shmpl 112 136 0 8 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 7507 0 6102 46 0 46 46 0 8 0 ffsino 240 7507 0 6102 83 0 83 83 0 8 0 nchpl 144 14783 0 14305 61 41 20 61 0 8 0 uvmvnodes 72 8101 0 0 148 0 148 148 0 8 0 vnodes 208 8101 0 0 427 0 427 427 0 8 0 namei 1024 49237 0 49237 3 2 1 1 0 8 1 vcpupl 1984 44 0 2 6 0 6 6 0 8 0 vmpool 520 62 0 20 5 2 3 3 0 8 0 scsiplug 64 3 0 3 3 3 0 1 0 8 0 scxspl 192 49285 0 49285 29 27 2 7 0 8 2 plimitpl 152 377 0 370 1 0 1 1 0 8 0 sigapl 432 3949 0 3935 2 0 2 2 0 8 0 futexpl 56 109405 0 109403 3 2 1 1 0 8 0 knotepl 112 1013 0 994 2 1 1 2 0 8 0 kqueuepl 104 1148 0 1146 7 6 1 4 0 8 0 pipepl 112 4004 0 3983 15 13 2 2 0 8 1 fdescpl 424 3950 0 3935 2 0 2 2 0 8 0 filepl 120 36047 0 35941 35 31 4 11 0 8 0 lockfpl 104 2402 0 2400 1 0 1 1 0 8 0 lockfspl 48 671 0 669 1 0 1 1 0 8 0 sessionpl 112 44 0 34 1 0 1 1 0 8 0 pgrppl 48 92 0 82 1 0 1 1 0 8 0 ucredpl 96 4515 0 4508 1 0 1 1 0 8 0 zombiepl 144 3936 0 3936 1 0 1 1 0 8 1 processpl 864 3967 0 3936 4 0 4 4 0 8 0 procpl 632 9149 0 9107 5 1 4 5 0 8 0 sosppl 128 52 0 52 15 14 1 1 0 8 1 sockpl 384 7836 0 7810 77 73 4 22 0 8 1 mcl64k 65536 907 0 907 73 72 1 33 0 8 1 mcl16k 16384 43 0 43 19 18 1 1 0 8 1 mcl12k 12288 120 0 120 20 19 1 1 0 8 1 mcl9k 9216 60 0 60 19 18 1 1 0 8 1 mcl8k 8192 187 0 187 11 10 1 1 0 8 1 mcl4k 4096 434 0 434 6 5 1 1 0 8 1 mcl2k2 2112 46 0 46 22 21 1 1 0 8 1 mcl2k 2048 76427 0 76384 20 13 7 13 0 8 0 mtagpl 80 211 0 211 7 6 1 1 0 8 1 mbufpl 256 157830 0 157751 159 147 12 34 0 8 2 bufpl 256 23642 0 15136 532 0 532 532 0 8 0 anonpl 16 530659 0 514620 239 149 90 96 0 62 9 amapchunkpl 152 23344 0 23223 91 85 6 16 0 158 0 amappl16 192 24818 0 23683 282 222 60 69 0 8 3 amappl15 184 318 0 318 6 5 1 1 0 8 1 amappl14 176 1534 0 1530 1 0 1 1 0 8 0 amappl13 168 237 0 237 7 7 0 1 0 8 0 amappl12 160 135 0 131 1 0 1 1 0 8 0 amappl11 152 729 0 718 1 0 1 1 0 8 0 amappl10 144 239 0 237 4 3 1 1 0 8 0 amappl9 136 1354 0 1347 1 0 1 1 0 8 0 amappl8 128 875 0 838 2 0 2 2 0 8 0 amappl7 120 363 0 355 1 0 1 1 0 8 0 amappl6 112 687 0 676 1 0 1 1 0 8 0 amappl5 104 484 0 474 1 0 1 1 0 8 0 amappl4 96 4162 0 4133 1 0 1 1 0 8 0 amappl3 88 960 0 944 1 0 1 1 0 8 0 amappl2 80 29531 0 29450 3 1 2 3 0 8 0 amappl1 72 86055 0 85612 25 15 10 20 0 8 0 amappl 80 9834 0 9768 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 64 137 0 8 3 0 3 3 0 8 0 uaddrrnd 24 4012 0 3935 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4012 0 3935 1 0 1 1 0 8 0 vmmpekpl 168 30517 0 30475 5 2 3 3 0 8 0 vmmpepl 168 494160 0 491729 423 279 144 148 0 357 35 vmsppl 272 3949 0 3935 4 3 1 2 0 8 0 pdppl 4096 8030 0 7952 13 3 10 11 0 8 0 pvpl 32 1500547 0 1481533 602 303 299 321 0 265 116 pmappl 200 4011 0 3955 4 1 3 4 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 990 0 321 21 1 20 20 0 8 0