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 206060 82872 0 0 0x4000480 1 syz-executor.1 *373266 68153 0 0x14000 0x40000200 0K 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(ffffffff8220ad56,ffffffff82209691,2cc,ffffffff8218fe90) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd806f30c1c0) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff8257fba0) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff8257fba0) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff8257fba0) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a10ed0) 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(ffffffff8220ad56,ffffffff82209691,2cc,ffffffff8218fe90) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd806f30c1c0) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff8257fba0) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff8257fba0) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff8257fba0) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a10ed0) 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 0xffff800020a24f90 rbx 0xffff800020a25040 rdx 0xffff800020a10ed0 rcx 0 rax 0 r8 0xffffffff8141590f kprintf+0x16f r9 0x1 r10 0x25 r11 0x4787b1cd52348e1c r12 0x3000000008 r13 0xffff800020a24fa0 r14 0x100 r15 0x1 rip 0xffffffff81991b58 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a24f80 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=373266 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020a113c0,0xffff800020a10c68 process=0xffff800020a12380 user=0xffff800020a20000, vmspace=0xffffffff82648c78 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 7144 294740 46447 0 2 0x480 syz-executor.0 7144 339919 46447 0 3 0x4000080 pipewr syz-executor.0 7144 22025 46447 0 3 0x4000080 fsleep syz-executor.0 82872 216465 1 0 2 0 syz-executor.1 82872 206060 1 0 7 0x4000480 syz-executor.1 82872 249262 1 0 3 0x4000080 fsleep syz-executor.1 46447 134551 96002 0 2 0x2 syz-executor.0 16726 71972 1 0 3 0x100083 ttyin getty 3941 16267 0 0 3 0x14200 acct acct 51041 170708 0 0 3 0x14200 bored sosplice 96002 51888 70662 0 3 0x82 thrsleep syz-fuzzer 96002 317843 70662 0 3 0x4000082 thrsleep syz-fuzzer 96002 467033 70662 0 3 0x4000082 thrsleep syz-fuzzer 96002 419021 70662 0 3 0x4000082 thrsleep syz-fuzzer 96002 46286 70662 0 3 0x4000082 thrsleep syz-fuzzer 96002 488931 70662 0 3 0x4000082 thrsleep syz-fuzzer 96002 361142 70662 0 3 0x4000082 thrsleep syz-fuzzer 96002 389967 70662 0 3 0x4000082 kqread syz-fuzzer 96002 103822 70662 0 3 0x4000082 thrsleep syz-fuzzer 96002 8476 70662 0 3 0x4000082 thrsleep syz-fuzzer 96002 480027 70662 0 3 0x4000082 thrsleep syz-fuzzer 70662 53570 7519 0 3 0x10008a pause ksh 7519 236203 98163 0 3 0x92 select sshd 98163 23126 1 0 3 0x80 select sshd 9025 320692 52585 74 3 0x100092 bpf pflogd 52585 219882 1 0 3 0x80 netio pflogd 44002 369883 14882 73 3 0x100090 kqread syslogd 14882 433770 1 0 3 0x100082 netio syslogd 81799 292179 1 77 3 0x100090 poll dhclient 50047 6269 1 0 3 0x80 poll dhclient 99925 389000 0 0 3 0x14200 pgzero zerothread 38475 261783 0 0 3 0x14200 aiodoned aiodoned 5425 166337 0 0 3 0x14200 syncer update 92911 26171 0 0 3 0x14200 cleaner cleaner 23791 228465 0 0 3 0x14200 reaper reaper 77354 33402 0 0 3 0x14200 pgdaemon pagedaemon 23213 341263 0 0 3 0x14200 bored crynlk 64391 8253 0 0 3 0x14200 bored crypto 78815 468780 0 0 3 0x40014200 acpi0 acpi0 81696 52950 0 0 3 0x40014200 idle1 22648 372599 0 0 2 0x14200 softnet 25424 240306 0 0 3 0x14200 bored systqmp 15331 73986 0 0 3 0x14200 bored systq *68153 373266 0 0 7 0x40014200 softclock 63162 256349 0 0 3 0x40014200 idle0 93512 247073 0 0 3 0x14200 bored smr 1 465097 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 68153 (softclock) thread 0xffff800020a10ed0 (373266) exclusive rwlock netlock r = 0 (0xffffffff824a7968) #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 (0xffffffff824a2798) #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 (0xffffffff8262dbe8) #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 9601 7156K 8261K 78643K 22541 0 0 pcb 13 10K 12K 78643K 1001 0 0 rtable 138 8K 9K 78643K 3565 0 0 ifaddr 98 26K 31K 78643K 1096 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1670 0 0 iov 0 0K 28K 78643K 6779 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1234 77K 78K 78643K 5781 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 51 0 0 VM map 30 15K 15K 78643K 58 0 0 sem 12 0K 1K 78643K 20120 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 7401 0 0 sigio 1 0K 0K 78643K 80 0 0 proc 62 63K 95K 78643K 2456 0 0 subproc 32 2K 2K 78643K 612 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 1K 78643K 544 0 0 in_multi 28 1K 2K 78643K 684 0 0 ether_multi 1 0K 0K 78643K 65 0 0 mrt 1 0K 0K 78643K 21 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 84 371K 371K 78643K 84 0 0 exec 0 0K 1K 78643K 1142 0 0 pfkey data 0 0K 4K 78643K 2 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 276K 278K 78643K 26165 0 0 UVM aobj 130 4K 4K 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 0K 78643K 1008 0 0 NDP 21 0K 1K 78643K 344 0 0 temp 236 3561K 4201K 78643K 131595 0 0 kqueue 0 0K 0K 78643K 45 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 64 106 0 101 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 489 0 487 1 0 1 1 0 8 0 rtentry 112 620 0 566 2 0 2 2 0 8 0 unpcb 120 33333 0 33321 20 18 2 3 0 8 1 syncache 264 26 0 26 15 15 0 1 0 8 0 tcpqe 32 21 0 21 10 10 0 1 0 8 0 tcpcb 544 26391 0 26387 41 39 2 12 0 8 1 inpcb 280 30880 0 30873 39 37 2 9 0 8 1 rttmr 72 7 0 7 5 5 0 1 0 8 0 ip6q 72 1 0 1 1 1 0 1 0 8 0 ip6af 40 2 0 2 1 1 0 1 0 8 0 nd6 48 95 0 94 2 1 1 1 0 8 0 pkpcb 40 22 0 22 10 10 0 1 0 8 0 ppxss 1128 154 0 154 20 19 1 1 0 8 1 pffrag 232 143 0 143 23 22 1 1 0 482 1 pffrnode 88 143 0 143 23 22 1 1 0 8 1 pffrent 40 5110 0 5110 23 22 1 1 0 8 1 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 24 456 0 384 1 0 1 1 0 8 0 pfstkey 112 457 0 385 4 1 3 3 0 8 0 pfstate 328 457 0 385 10 3 7 7 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 4 0 0 4 0 4 4 0 8 0 art_heap4 256 2536 0 2336 24 7 17 18 0 8 0 art_table 32 2540 0 2336 3 0 3 3 0 8 0 art_node 16 617 0 573 1 0 1 1 0 8 0 sysvmsgpl 40 13 0 9 1 0 1 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 20116 0 20106 1 0 1 1 0 8 0 shmpl 112 129 0 1 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 14313 0 12886 47 0 47 47 0 8 0 ffsino 272 14313 0 12886 96 0 96 96 0 8 0 nchpl 144 29412 0 28943 61 41 20 61 0 8 0 uvmvnodes 72 5945 0 0 109 0 109 109 0 8 0 vnodes 208 5945 0 0 313 0 313 313 0 8 0 namei 1024 137706 0 137706 4 3 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 28 0 0 4 0 4 4 0 8 0 vmpool 552 56 0 28 3 0 3 3 0 8 1 scsiplug 64 3 0 3 2 2 0 1 0 8 0 scxspl 192 78329 0 78329 54 51 3 4 0 8 3 plimitpl 152 365 0 357 1 0 1 1 0 8 0 sigapl 432 7504 0 7489 3 1 2 3 0 8 0 futexpl 56 470768 0 470766 3 2 1 1 0 8 0 knotepl 112 1375 0 1356 3 2 1 2 0 8 0 kqueuepl 104 1496 0 1494 4 3 1 4 0 8 0 pipepl 112 8558 0 8539 10 8 2 2 0 8 1 fdescpl 488 7505 0 7489 3 0 3 3 0 8 0 filepl 152 137762 0 137661 60 53 7 14 0 8 3 lockfpl 104 6955 0 6954 1 0 1 1 0 8 0 lockfspl 48 3230 0 3229 1 0 1 1 0 8 0 sessionpl 112 57 0 46 1 0 1 1 0 8 0 pgrppl 48 111 0 100 1 0 1 1 0 8 0 ucredpl 96 14722 0 14712 1 0 1 1 0 8 0 zombiepl 144 7491 0 7490 1 0 1 1 0 8 0 processpl 896 7524 0 7490 4 0 4 4 0 8 0 procpl 632 20860 0 20812 8 3 5 5 0 8 0 srpgc 64 67 0 67 21 20 1 1 0 8 1 sosppl 128 139 0 139 21 21 0 1 0 8 0 sockpl 384 64828 0 64806 101 94 7 14 0 8 4 mcl64k 65536 819 0 0 86 20 66 66 0 8 0 mcl16k 16384 17 0 0 3 0 3 3 0 8 0 mcl12k 12288 33 0 0 2 0 2 2 0 8 0 mcl9k 9216 21 0 0 2 0 2 2 0 8 0 mcl8k 8192 33 0 0 4 1 3 3 0 8 0 mcl4k 4096 27 0 0 4 1 3 3 0 8 0 mcl2k2 2112 10 0 0 1 0 1 1 0 8 0 mcl2k 2048 211 0 0 23 4 19 23 0 8 0 mtagpl 80 86 0 0 1 0 1 1 0 8 0 mbufpl 256 955 0 0 37 0 37 37 0 8 0 bufpl 256 27721 0 20673 441 0 441 441 0 8 0 anonpl 16 841997 0 819570 243 140 103 104 0 124 9 amapchunkpl 152 46635 0 46442 104 89 15 21 0 158 5 amappl16 192 39205 0 37946 250 176 74 76 0 8 8 amappl15 184 2141 0 2141 4 4 0 1 0 8 0 amappl14 176 1207 0 1202 1 0 1 1 0 8 0 amappl13 168 1628 0 1627 1 0 1 1 0 8 0 amappl12 160 190 0 190 4 4 0 1 0 8 0 amappl11 152 852 0 837 1 0 1 1 0 8 0 amappl10 144 907 0 901 1 0 1 1 0 8 0 amappl9 136 1622 0 1616 1 0 1 1 0 8 0 amappl8 128 1133 0 1092 3 1 2 2 0 8 0 amappl7 120 1086 0 1077 1 0 1 1 0 8 0 amappl6 112 791 0 779 1 0 1 1 0 8 0 amappl5 104 3437 0 3422 1 0 1 1 0 8 0 amappl4 96 8001 0 7968 1 0 1 1 0 8 0 amappl3 88 910 0 901 1 0 1 1 0 8 0 amappl2 80 62261 0 62178 3 1 2 3 0 8 0 amappl1 72 156751 0 156288 25 15 10 20 0 8 0 amappl 80 21830 0 21760 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 1 3 0 3 3 0 8 0 uaddrrnd 24 7561 0 7489 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 7561 0 7489 1 0 1 1 0 8 0 vmmpekpl 168 64251 0 64208 3 0 3 3 0 8 0 vmmpepl 168 932491 0 929932 423 275 148 155 0 357 31 vmsppl 368 7504 0 7489 2 0 2 2 0 8 0 pdppl 4096 15129 0 15062 11 2 9 9 0 8 0 pvpl 32 2161597 0 2137657 436 211 225 230 0 265 27 pmappl 232 7560 0 7517 3 0 3 3 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 787 0 80 21 0 21 21 0 8 0