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 432447 69372 0 0 0 1 syz-executor.0 *216148 74989 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(ffffffff82207e16,ffffffff82206908,2cc,ffffffff821905c6) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd806270d1c8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825f6038) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825f6038) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825f6038) 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(ffffffff82207e16,ffffffff82206908,2cc,ffffffff821905c6) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd806270d1c8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825f6038) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825f6038) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825f6038) 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 0xffff800020a25380 rbx 0xffff800020a25430 rdx 0xffff800020a109e0 rcx 0 rax 0 r8 0xffffffff81da132f kprintf+0x16f r9 0x1 r10 0x25 r11 0x93a393f177dc7747 r12 0x3000000008 r13 0xffff800020a25390 r14 0x100 r15 0x1 rip 0xffffffff82104c58 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a25370 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=216148 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020a113c0,0xffff800020a10010 process=0xffff800020a12000 user=0xffff800020a20000, vmspace=0xffffffff82623510 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 69372 432447 15801 0 7 0 syz-executor.0 69372 215024 15801 0 3 0x4000080 netio syz-executor.0 69372 405949 15801 0 3 0x4000080 fsleep syz-executor.0 88178 12290 50126 0 3 0x82 piperd syz-executor.1 15801 156756 50126 0 2 0x482 syz-executor.0 87600 324820 1 0 3 0x100083 ttyin getty 8169 347085 0 0 3 0x14200 acct acct 90626 111612 0 0 3 0x14200 bored sosplice 50126 463065 51555 0 3 0x82 thrsleep syz-fuzzer 50126 72931 51555 0 3 0x4000082 thrsleep syz-fuzzer 50126 25323 51555 0 3 0x4000082 thrsleep syz-fuzzer 50126 443183 51555 0 3 0x4000082 thrsleep syz-fuzzer 50126 279138 51555 0 3 0x4000082 thrsleep syz-fuzzer 50126 29713 51555 0 3 0x4000082 kqread syz-fuzzer 50126 15999 51555 0 3 0x4000082 thrsleep syz-fuzzer 50126 394735 51555 0 3 0x4000082 thrsleep syz-fuzzer 50126 86255 51555 0 3 0x4000082 thrsleep syz-fuzzer 50126 141397 51555 0 3 0x4000082 thrsleep syz-fuzzer 51555 66155 67075 0 3 0x10008a pause ksh 67075 362451 52060 0 3 0x92 select sshd 52060 252390 1 0 3 0x80 select sshd 25838 142190 71626 74 3 0x100092 bpf pflogd 71626 47293 1 0 3 0x80 netio pflogd 27865 159288 18146 73 3 0x100090 kqread syslogd 18146 338284 1 0 3 0x100082 netio syslogd 56287 295482 1 77 3 0x100090 poll dhclient 25592 393654 1 0 3 0x80 poll dhclient 82177 487193 0 0 3 0x14200 pgzero zerothread 43711 285469 0 0 3 0x14200 aiodoned aiodoned 41307 388632 0 0 3 0x14200 syncer update 92324 445464 0 0 3 0x14200 cleaner cleaner 32411 503945 0 0 3 0x14200 reaper reaper 81298 464822 0 0 3 0x14200 pgdaemon pagedaemon 8522 232374 0 0 3 0x14200 bored crynlk 16967 407601 0 0 3 0x14200 bored crypto 43453 117168 0 0 3 0x40014200 acpi0 acpi0 44360 484389 0 0 3 0x40014200 idle1 97063 233186 0 0 3 0x14200 bored softnet 53859 497307 0 0 3 0x14200 bored systqmp 72934 21983 0 0 3 0x14200 bored systq *74989 216148 0 0 7 0x40014200 softclock 30827 271718 0 0 3 0x40014200 idle0 11675 363086 0 0 3 0x14200 bored smr 1 274640 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 74989 (softclock) thread 0xffff800020a109e0 (216148) exclusive rwlock netlock r = 0 (0xffffffff824b5dc8) #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 (0xffffffff824e4300) #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 (0xffffffff82677568) #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 9607 7101K 8386K 78643K 26990 0 0 pcb 13 12K 14K 78643K 1502 0 0 rtable 116 13K 14K 78643K 5113 0 0 ifaddr 92 25K 27K 78643K 1532 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1913 0 0 iov 0 0K 28K 78643K 1477 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1222 77K 77K 78643K 7949 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 95 0 0 VM map 56 28K 28K 78643K 86 0 0 sem 12 1K 1K 78643K 305 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 6974 0 0 sigio 0 0K 0K 78643K 111 0 0 proc 62 63K 95K 78643K 2896 0 0 subproc 32 2K 2K 78643K 751 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 750 0 0 in_multi 28 1K 2K 78643K 948 0 0 ether_multi 1 0K 0K 78643K 81 0 0 mrt 0 0K 0K 78643K 52 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 150 662K 662K 78643K 150 0 0 exec 0 0K 1K 78643K 1456 0 0 pfkey data 0 0K 4K 78643K 6 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 211 471K 481K 78643K 25767 0 0 UVM aobj 130 4K 5K 78643K 144 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 1490 0 0 NDP 21 0K 1K 78643K 489 0 0 temp 237 3565K 4205K 78643K 250715 0 0 kqueue 0 0K 0K 78643K 53 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 64 171 0 164 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 653 0 651 1 0 1 1 0 8 0 rtentry 112 856 0 815 2 0 2 2 0 8 0 unpcb 120 8546 0 8531 6 5 1 2 0 8 0 syncache 264 35 0 35 14 13 1 1 0 8 1 sackhl 24 3 0 3 2 2 0 1 0 8 0 tcpqe 32 51 0 51 9 8 1 1 0 8 1 tcpcb 544 3166 0 3160 30 29 1 12 0 8 0 inpcb 280 9603 0 9594 49 47 2 13 0 8 1 rttmr 72 16 0 16 10 9 1 1 0 8 1 ip6q 72 1 0 1 1 1 0 1 0 8 0 ip6af 40 3 0 3 1 1 0 1 0 8 0 nd6 48 126 0 124 4 3 1 1 0 8 0 pkpcb 40 52 0 52 14 14 0 1 0 8 0 swfcl 56 3 0 0 1 0 1 1 0 8 0 ppxss 1128 221 0 221 17 16 1 1 0 8 1 pffrag 232 145 0 145 16 15 1 1 0 482 1 pffrnode 88 145 0 145 16 15 1 1 0 8 1 pffrent 40 4672 0 4672 16 15 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 24 538 0 492 1 0 1 1 0 8 0 pfstkey 112 538 0 492 3 1 2 3 0 8 0 pfstate 328 538 0 492 11 5 6 8 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 20 0 19 13 12 1 3 0 8 0 art_heap4 256 3594 0 3379 51 34 17 17 0 8 0 art_table 32 3614 0 3398 3 0 3 3 0 8 0 art_node 16 855 0 818 1 0 1 1 0 8 0 sysvmsgpl 40 29 0 23 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 303 0 293 1 0 1 1 0 8 0 shmpl 112 142 0 14 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 12347 0 10928 46 0 46 46 0 8 0 ffsino 272 12347 0 10928 96 1 95 95 0 8 0 nchpl 144 22882 0 21236 63 1 62 62 0 8 0 uvmvnodes 72 5961 0 0 109 0 109 109 0 8 0 vnodes 208 5961 0 0 314 0 314 314 0 8 0 namei 1024 98005 0 98005 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 54 0 0 7 0 7 7 0 8 0 vmpool 552 84 0 30 4 0 4 4 0 8 0 scsiplug 64 12 0 12 9 8 1 1 0 8 1 scxspl 192 76995 0 76995 43 42 1 7 0 8 1 plimitpl 152 620 0 612 1 0 1 1 0 8 0 sigapl 432 7053 0 7038 5 3 2 3 0 8 0 futexpl 56 160742 0 160741 2 1 1 1 0 8 0 knotepl 112 1889 0 1870 8 7 1 3 0 8 0 kqueuepl 104 1924 0 1922 8 7 1 4 0 8 0 pipepl 112 4750 0 4731 10 9 1 2 0 8 0 fdescpl 488 7054 0 7038 3 0 3 3 0 8 0 filepl 152 75510 0 75402 58 52 6 14 0 8 1 lockfpl 104 2187 0 2186 1 0 1 1 0 8 0 lockfspl 48 769 0 768 1 0 1 1 0 8 0 sessionpl 112 65 0 54 1 0 1 1 0 8 0 pgrppl 48 152 0 141 1 0 1 1 0 8 0 ucredpl 96 23005 0 22996 1 0 1 1 0 8 0 zombiepl 144 7041 0 7041 2 1 1 1 0 8 1 processpl 896 7074 0 7041 5 1 4 5 0 8 0 procpl 632 22785 0 22741 6 1 5 5 0 8 0 srpgc 64 66 0 66 20 19 1 1 0 8 1 sosppl 128 90 0 90 22 22 0 1 0 8 0 sockpl 384 18920 0 18894 72 68 4 22 0 8 1 mcl64k 65536 465 0 0 52 19 33 34 0 8 0 mcl16k 16384 32 0 0 4 2 2 3 0 8 0 mcl12k 12288 33 0 0 2 0 2 2 0 8 0 mcl9k 9216 23 0 0 2 0 2 2 0 8 0 mcl8k 8192 25 0 0 4 1 3 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 11 0 0 1 0 1 1 0 8 0 mcl2k 2048 168 0 0 19 0 19 19 0 8 2 mtagpl 80 92 0 0 1 0 1 1 0 8 0 mbufpl 256 879 0 0 43 0 43 43 0 8 0 bufpl 256 30693 0 23645 441 0 441 441 0 8 0 anonpl 16 880968 0 861876 279 186 93 94 0 124 12 amapchunkpl 152 53681 0 53539 80 67 13 20 0 158 4 amappl16 192 40249 0 39147 277 213 64 68 0 8 8 amappl15 184 966 0 966 5 5 0 1 0 8 0 amappl14 176 1028 0 1025 1 0 1 1 0 8 0 amappl13 168 1392 0 1391 8 7 1 1 0 8 0 amappl12 160 210 0 209 2 1 1 1 0 8 0 amappl11 152 746 0 731 1 0 1 1 0 8 0 amappl10 144 829 0 824 1 0 1 1 0 8 0 amappl9 136 2460 0 2452 1 0 1 1 0 8 0 amappl8 128 1966 0 1911 2 0 2 2 0 8 0 amappl7 120 1011 0 1003 1 0 1 1 0 8 0 amappl6 112 731 0 714 1 0 1 1 0 8 0 amappl5 104 687 0 672 1 0 1 1 0 8 0 amappl4 96 6889 0 6854 1 0 1 1 0 8 0 amappl3 88 1743 0 1728 1 0 1 1 0 8 0 amappl2 80 54430 0 54352 3 1 2 3 0 8 0 amappl1 72 169031 0 168586 25 15 10 20 0 8 0 amappl 80 23811 0 23738 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 64 143 0 14 3 0 3 3 0 8 0 uaddrrnd 24 7138 0 7038 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 7138 0 7038 1 0 1 1 0 8 0 vmmpekpl 168 61372 0 61328 3 0 3 3 0 8 0 vmmpepl 168 916275 0 913857 371 224 147 150 0 357 34 vmsppl 368 7053 0 7038 2 0 2 2 0 8 0 pdppl 4096 14283 0 14190 15 3 12 12 0 8 0 pvpl 32 2351581 0 2329833 488 277 211 218 0 265 28 pmappl 232 7137 0 7068 5 0 5 5 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 783 0 106 20 0 20 20 0 8 0