panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 716 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 40686 38854 0 0x14000 0x40000200 0K softclock 9347 65175 0 0x14000 0x200 1 smr 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(ffffffff82206ea2,ffffffff82204a3b,2cc,ffffffff8218c169) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd806616f4d8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825538c0) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825538c0) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825538c0) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a109e0) at softclock_thread+0x16a sys/kern/kern_timeout.c:553 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 716 ddb{0}> 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(ffffffff82206ea2,ffffffff82204a3b,2cc,ffffffff8218c169) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd806616f4d8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825538c0) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825538c0) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825538c0) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a109e0) at softclock_thread+0x16a sys/kern/kern_timeout.c:553 end trace frame: 0x0, count: -7 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020a25ca0 rbx 0xffff800020a25d50 rdx 0xffff800020a109e0 rcx 0 rax 0 r8 0xffffffff81ee69df kprintf+0x16f r9 0x1 r10 0x25 r11 0x2c38828d272d6e1d r12 0x3000000008 r13 0xffff800020a25cb0 r14 0x100 r15 0x1 rip 0xffffffff81d72d68 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a25c90 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=40686 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020a10c58,0xffff800020a10500 process=0xffff800020a12a80 user=0xffff800020a20000, vmspace=0xffffffff8264c400 estcpu=0, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 36953 405235 28571 0 2 0 syz-executor.0 36953 460491 28571 0 2 0x4000000 syz-executor.0 89289 152648 83881 0 2 0x482 syz-executor.1 28571 500383 83881 0 2 0x482 syz-executor.0 58572 126974 1 0 3 0x100083 ttyin getty 99573 108413 0 0 3 0x14200 bored sosplice 83881 433278 52734 0 3 0x82 thrsleep syz-fuzzer 83881 401949 52734 0 2 0x4000482 syz-fuzzer 83881 389917 52734 0 3 0x4000082 thrsleep syz-fuzzer 83881 514080 52734 0 3 0x4000082 thrsleep syz-fuzzer 83881 366260 52734 0 3 0x4000082 thrsleep syz-fuzzer 83881 112668 52734 0 2 0x4000002 syz-fuzzer 83881 52783 52734 0 3 0x4000082 thrsleep syz-fuzzer 83881 233909 52734 0 3 0x4000082 thrsleep syz-fuzzer 83881 23568 52734 0 3 0x4000082 kqread syz-fuzzer 83881 468781 52734 0 2 0x4000482 syz-fuzzer 52734 320635 22854 0 3 0x10008a pause ksh 22854 368095 15204 0 3 0x92 select sshd 15204 239065 1 0 3 0x80 select sshd 28167 120458 21994 74 2 0x100492 pflogd 21994 290298 1 0 3 0x80 netio pflogd 6879 433648 10089 73 3 0x100090 kqread syslogd 10089 295924 1 0 3 0x100082 netio syslogd 57199 54858 1 77 3 0x100090 poll dhclient 65286 307528 1 0 3 0x80 poll dhclient 68574 79718 0 0 2 0x14200 zerothread 86310 199424 0 0 3 0x14200 aiodoned aiodoned 63176 5620 0 0 2 0x14200 update 82375 284076 0 0 3 0x14200 cleaner cleaner 59720 242905 0 0 3 0x14200 reaper reaper 95440 185195 0 0 3 0x14200 pgdaemon pagedaemon 21944 135581 0 0 3 0x14200 bored crynlk 5984 331622 0 0 3 0x14200 bored crypto 54392 142075 0 0 3 0x40014200 acpi0 acpi0 18010 106963 0 0 3 0x40014200 idle1 52105 249233 0 0 2 0x14200 softnet 67417 7971 0 0 2 0x14200 systqmp 33407 495458 0 0 3 0x14200 bored systq *38854 40686 0 0 7 0x40014200 softclock 22996 318962 0 0 3 0x40014200 idle0 65175 9347 0 0 7 0x14200 smr 1 370511 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 38854 (softclock) thread 0xffff800020a109e0 (40686) exclusive rwlock netlock r = 0 (0xffffffff82464b38) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 arptimer+0x22 sys/netinet/if_ether.c:119 #2 timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] #2 timeout_run+0xc4 sys/kern/kern_timeout.c:474 #3 softclock_thread+0x16a sys/kern/kern_timeout.c:553 #4 proc_trampoline+0x1c shared rwlock timeout r = 0 (0xffffffff8248c8f0) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 timeout_run+0xb9 sys/kern/kern_timeout.c:473 #2 softclock_thread+0x16a sys/kern/kern_timeout.c:553 #3 proc_trampoline+0x1c exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8266bc00) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 __mp_acquire_count+0x51 sys/kern/kern_lock.c:227 #2 mi_switch+0x392 sys/kern/sched_bsd.c:436 #3 sleep_finish+0x113 sys/kern/kern_synch.c:373 #4 softclock_thread+0x103 sys/kern/kern_timeout.c:548 #5 proc_trampoline+0x1c ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9605 6532K 14612K 78643K 17861 0 0 pcb 13 8K 8K 78643K 427 0 0 rtable 122 13K 13K 78643K 1634 0 0 ifaddr 93 18K 19K 78643K 490 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1620 0 0 iov 0 0K 16K 78643K 363 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1213 76K 77K 78643K 4400 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 5K 78643K 35 0 0 VM map 19 9K 10K 78643K 22 0 0 sem 12 0K 0K 78643K 448 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 2311 0 0 sigio 0 0K 0K 78643K 30 0 0 proc 61 63K 95K 78643K 1421 0 0 subproc 32 2K 2K 78643K 357 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 204 0 0 in_multi 37 2K 2K 78643K 314 0 0 ether_multi 1 0K 0K 78643K 28 0 0 mrt 0 0K 0K 78643K 11 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 72 318K 318K 78643K 72 0 0 exec 0 0K 1K 78643K 649 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 148 169K 170K 78643K 10175 0 0 UVM aobj 126 6K 6K 78643K 131 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 471 0 0 NDP 22 0K 1K 78643K 150 0 0 temp 242 3565K 3636K 78643K 74674 0 0 kqueue 0 0K 0K 78643K 18 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 51 0 45 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 194 0 192 1 0 1 1 0 8 0 rtentry 112 290 0 245 2 0 2 2 0 8 0 unpcb 120 5452 0 5438 12 11 1 2 0 8 0 syncache 264 21 0 21 10 10 0 1 0 8 0 tcpqe 32 6 0 6 5 5 0 1 0 8 0 tcpcb 544 869 0 865 1 0 1 1 0 8 0 inpcb 280 2662 0 2655 28 27 1 3 0 8 0 rttmr 72 5 0 5 2 2 0 1 0 8 0 ip6q 72 4 0 4 2 2 0 1 0 8 0 ip6af 40 12 0 12 2 2 0 1 0 8 0 nd6 48 48 0 43 1 0 1 1 0 8 0 pkpcb 40 8 0 8 4 4 0 1 0 8 0 swfcl 56 2 0 0 1 0 1 1 0 8 0 ppxss 1128 58 0 58 44 44 0 1 0 8 0 pffrag 232 56 0 56 31 31 0 1 0 482 0 pffrnode 88 56 0 56 31 31 0 1 0 8 0 pffrent 40 1710 0 1710 31 31 0 1 0 8 0 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 257 0 248 1 0 1 1 0 8 0 pfstkey 112 257 0 248 1 0 1 1 0 8 0 pfstate 328 257 0 248 6 5 1 3 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 14 0 13 10 9 1 3 0 8 0 art_heap4 256 1365 0 1130 28 13 15 18 0 8 0 art_table 32 1379 0 1143 3 0 3 3 0 8 0 art_node 16 289 0 248 1 0 1 1 0 8 0 sysvmsgpl 40 21 0 5 1 0 1 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 446 0 436 1 0 1 1 0 8 0 shmpl 112 129 0 5 5 1 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 4607 0 3210 46 0 46 46 0 8 0 ffsino 272 4607 0 3210 94 0 94 94 0 8 0 nchpl 144 8133 0 7649 61 41 20 61 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 208 5926 0 0 312 0 312 312 0 8 0 namei 1024 37555 0 37555 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 17 0 0 3 0 3 3 0 8 0 vmpool 552 20 0 3 2 0 2 2 0 8 0 scsiplug 64 5 0 5 4 4 0 1 0 8 0 scxspl 192 25017 0 25017 26 25 1 7 0 8 1 plimitpl 152 162 0 154 1 0 1 1 0 8 0 sigapl 432 2455 0 2440 7 5 2 3 0 8 0 futexpl 56 76972 0 76972 1 0 1 1 0 8 1 knotepl 112 853 0 834 5 4 1 2 0 8 0 kqueuepl 104 2968 0 2963 3 2 1 2 0 8 0 pipepl 112 4164 0 4143 18 17 1 2 0 8 0 fdescpl 488 2456 0 2440 3 0 3 3 0 8 0 filepl 152 38357 0 38244 102 96 6 8 0 8 1 lockfpl 104 2538 0 2536 1 0 1 1 0 8 0 lockfspl 48 663 0 661 1 0 1 1 0 8 0 sessionpl 112 38 0 27 1 0 1 1 0 8 0 pgrppl 48 61 0 50 1 0 1 1 0 8 0 ucredpl 96 1904 0 1895 1 0 1 1 0 8 0 zombiepl 144 2440 0 2439 1 0 1 1 0 8 0 processpl 896 2472 0 2439 4 0 4 4 0 8 0 procpl 632 8049 0 8006 6 1 5 5 0 8 0 srpgc 64 36 0 36 11 11 0 1 0 8 0 sosppl 128 29 0 29 13 13 0 1 0 8 0 sockpl 384 8337 0 8314 96 92 4 6 0 8 1 mcl64k 65536 529 0 0 67 63 4 67 0 8 0 mcl16k 16384 65 0 0 6 3 3 3 0 8 0 mcl12k 12288 34 0 0 2 0 2 2 0 8 0 mcl9k 9216 17 0 0 2 0 2 2 0 8 0 mcl8k 8192 28 0 0 4 1 3 3 0 8 0 mcl4k 4096 29 0 0 4 1 3 3 0 8 0 mcl2k2 2112 4 0 0 1 0 1 1 0 8 0 mcl2k 2048 248 0 0 19 12 7 19 0 8 0 mtagpl 80 54 0 0 1 0 1 1 0 8 0 mbufpl 256 1699 0 0 42 5 37 39 0 8 0 bufpl 256 14214 0 7166 441 0 441 441 0 8 0 anonpl 16 1893629 0 1867095 534 427 107 125 0 124 0 amapchunkpl 152 26032 0 25637 77 58 19 19 0 158 2 amappl16 192 104138 0 102830 554 488 66 78 0 8 0 amappl15 184 100 0 99 1 0 1 1 0 8 0 amappl14 176 338 0 334 1 0 1 1 0 8 0 amappl13 168 453 0 453 2 2 0 1 0 8 0 amappl12 160 393 0 392 4 3 1 1 0 8 0 amappl11 152 436 0 420 1 0 1 1 0 8 0 amappl10 144 49 0 45 1 0 1 1 0 8 0 amappl9 136 1456 0 1450 1 0 1 1 0 8 0 amappl8 128 998 0 958 3 1 2 2 0 8 0 amappl7 120 155 0 145 1 0 1 1 0 8 0 amappl6 112 424 0 412 1 0 1 1 0 8 0 amappl5 104 1007 0 992 1 0 1 1 0 8 0 amappl4 96 2891 0 2858 1 0 1 1 0 8 0 amappl3 88 887 0 879 1 0 1 1 0 8 0 amappl2 80 17768 0 17696 3 1 2 3 0 8 0 amappl1 72 67068 0 66629 26 16 10 20 0 8 0 amappl 80 9035 0 8984 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 64 130 0 5 3 0 3 3 0 8 0 uaddrrnd 24 2476 0 2440 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2476 0 2440 1 0 1 1 0 8 0 vmmpekpl 168 31177 0 31144 3 1 2 2 0 8 0 vmmpepl 168 416775 0 414289 659 544 115 156 0 357 2 vmsppl 368 2455 0 2440 2 0 2 2 0 8 0 pdppl 4096 4959 0 4903 12 4 8 8 0 8 0 pvpl 32 2605807 0 2579616 863 649 214 253 0 265 0 pmappl 232 2475 0 2443 6 4 2 3 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 738 0 114 20 0 20 20 0 8 0