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 61997 82455 0 0 0 1 syz-executor.0 *507390 62972 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(ffffffff82205e21,ffffffff82203673,2cc,ffffffff8218b2fd) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd80653f3388) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825595d0) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825595d0) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825595d0) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a10768) 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(ffffffff82205e21,ffffffff82203673,2cc,ffffffff8218b2fd) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd80653f3388) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825595d0) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825595d0) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825595d0) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a10768) 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 0xffff800020a25a10 rbx 0xffff800020a25ac0 rdx 0xffff800020a10768 rcx 0 rax 0 r8 0xffffffff8188b28f kprintf+0x16f r9 0x1 r10 0x25 r11 0x8b7de0c8487904e0 r12 0x3000000008 r13 0xffff800020a25a20 r14 0x100 r15 0x1 rip 0xffffffff81bab4d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a25a00 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=507390 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020a109e0,0xffff800020a10010 process=0xffff800020a12a80 user=0xffff800020a20000, vmspace=0xffffffff826539f0 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 82455 61997 89363 0 7 0 syz-executor.0 89363 362786 74879 0 2 0x482 syz-executor.0 82062 446302 74879 0 2 0x482 syz-executor.1 14877 332303 1 0 3 0x100083 ttyin getty 10626 282319 0 0 3 0x14200 acct acct 81889 400844 0 0 3 0x14200 bored sosplice 74879 379422 35797 0 3 0x82 thrsleep syz-fuzzer 74879 19642 35797 0 2 0x4000482 syz-fuzzer 74879 63955 35797 0 3 0x4000082 thrsleep syz-fuzzer 74879 267579 35797 0 3 0x4000082 thrsleep syz-fuzzer 74879 80457 35797 0 3 0x4000082 kqread syz-fuzzer 74879 334950 35797 0 2 0x4000482 syz-fuzzer 74879 436232 35797 0 3 0x4000082 thrsleep syz-fuzzer 74879 241799 35797 0 3 0x4000082 thrsleep syz-fuzzer 74879 18019 35797 0 3 0x4000082 thrsleep syz-fuzzer 74879 158187 35797 0 3 0x4000082 thrsleep syz-fuzzer 35797 312805 56729 0 3 0x10008a pause ksh 56729 332230 24947 0 3 0x92 select sshd 24947 135487 1 0 3 0x80 select sshd 79320 187214 10634 74 3 0x100092 bpf pflogd 10634 304479 1 0 3 0x80 netio pflogd 55703 346117 63671 73 3 0x100090 kqread syslogd 63671 461552 1 0 3 0x100082 netio syslogd 92120 395199 1 77 3 0x100090 poll dhclient 62362 81401 1 0 3 0x80 poll dhclient 72124 418967 0 0 3 0x14200 pgzero zerothread 32099 288172 0 0 3 0x14200 aiodoned aiodoned 38273 119637 0 0 3 0x14200 syncer update 10065 129710 0 0 3 0x14200 cleaner cleaner 74121 38339 0 0 3 0x14200 reaper reaper 33584 437031 0 0 3 0x14200 pgdaemon pagedaemon 82765 312126 0 0 3 0x14200 bored crynlk 16723 478756 0 0 3 0x14200 bored crypto 77351 46422 0 0 3 0x40014200 acpi0 acpi0 21396 53126 0 0 3 0x40014200 idle1 46587 282950 0 0 3 0x14200 bored softnet 62853 215990 0 0 3 0x14200 bored systqmp 56772 314706 0 0 3 0x14200 bored systq *62972 507390 0 0 7 0x40014200 softclock 72363 39958 0 0 3 0x40014200 idle0 570 6522 0 0 3 0x14200 bored smr 1 383809 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 62972 (softclock) thread 0xffff800020a10768 (507390) exclusive rwlock netlock r = 0 (0xffffffff824e8728) #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 (0xffffffff824b7f68) #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 (0xffffffff8266bc58) #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 9627 6597K 7563K 78643K 18428 0 0 pcb 13 10K 12K 78643K 687 0 0 rtable 110 13K 14K 78643K 2388 0 0 ifaddr 100 21K 24K 78643K 700 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1638 0 0 iov 0 0K 28K 78643K 1722 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1225 77K 78K 78643K 4114 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 55 0 0 VM map 18 9K 9K 78643K 26 0 0 sem 12 0K 1K 78643K 1626 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 3119 0 0 sigio 0 0K 0K 78643K 1050 0 0 proc 62 63K 95K 78643K 1631 0 0 subproc 32 2K 2K 78643K 391 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 246 0 0 in_multi 24 1K 2K 78643K 431 0 0 ether_multi 1 0K 0K 78643K 39 0 0 mrt 0 0K 0K 78643K 19 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 823 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 163 179K 195K 78643K 11976 0 0 UVM aobj 130 6K 6K 78643K 158 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 2K 78643K 806 0 0 NDP 24 0K 1K 78643K 221 0 0 temp 258 3565K 3641K 78643K 92351 0 0 kqueue 0 0K 0K 78643K 31 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 64 101 0 96 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 266 0 264 1 0 1 1 0 8 0 rtentry 112 423 0 386 2 0 2 2 0 8 0 unpcb 120 1754 0 1744 2 1 1 2 0 8 0 syncache 264 18 0 18 4 4 0 1 0 8 0 tcpqe 32 46 0 46 4 4 0 1 0 8 0 tcpcb 544 1392 0 1388 13 12 1 11 0 8 0 inpcb 280 6275 0 6268 23 21 2 10 0 8 1 rttmr 72 7 0 6 2 1 1 1 0 8 0 ip6q 72 1 0 1 1 1 0 1 0 8 0 ip6af 40 1 0 1 1 1 0 1 0 8 0 nd6 48 56 0 54 1 0 1 1 0 8 0 pkpcb 40 19 0 19 8 8 0 1 0 8 0 swfcl 56 4 0 0 1 0 1 1 0 8 0 ppxss 1128 86 0 86 12 11 1 1 0 8 1 pffrag 232 82 0 82 12 11 1 1 0 482 1 pffrnode 88 82 0 82 12 11 1 1 0 8 1 pffrent 40 2651 0 2651 12 11 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 24 233 0 167 1 0 1 1 0 8 0 pfstkey 112 233 0 167 3 0 3 3 0 8 0 pfstate 328 233 0 167 6 0 6 6 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 21 0 20 6 5 1 3 0 8 0 art_heap4 256 1900 0 1693 27 11 16 20 0 8 0 art_table 32 1921 0 1713 4 2 2 3 0 8 0 art_node 16 422 0 388 1 0 1 1 0 8 0 sysvmsgpl 40 47 0 25 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 1624 0 1614 1 0 1 1 0 8 0 shmpl 112 156 0 28 5 1 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 6130 0 4710 47 0 47 47 0 8 0 ffsino 272 6130 0 4710 96 0 96 96 0 8 0 nchpl 144 11370 0 10918 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 37411 0 37411 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 17 0 1 3 0 3 3 0 8 0 vmpool 552 24 0 8 3 1 2 2 0 8 0 scxspl 192 36444 0 36444 31 30 1 7 0 8 1 plimitpl 152 261 0 252 1 0 1 1 0 8 0 sigapl 432 3257 0 3242 4 2 2 3 0 8 0 futexpl 56 80116 0 80116 1 0 1 1 0 8 1 knotepl 112 868 0 849 2 1 1 2 0 8 0 kqueuepl 104 915 0 913 5 4 1 4 0 8 0 pipepl 112 6890 0 6871 15 13 2 3 0 8 1 fdescpl 488 3258 0 3242 3 0 3 3 0 8 0 filepl 152 32815 0 32715 31 26 5 14 0 8 1 lockfpl 104 1171 0 1170 1 0 1 1 0 8 0 lockfspl 48 414 0 413 1 0 1 1 0 8 0 sessionpl 112 40 0 29 1 0 1 1 0 8 0 pgrppl 48 61 0 50 1 0 1 1 0 8 0 ucredpl 96 2846 0 2837 1 0 1 1 0 8 0 zombiepl 144 3243 0 3242 2 1 1 1 0 8 0 processpl 896 3276 0 3242 4 0 4 4 0 8 0 procpl 632 10083 0 10040 6 1 5 5 0 8 1 srpgc 64 38 0 38 9 9 0 1 0 8 0 sosppl 128 56 0 56 10 10 0 1 0 8 0 sockpl 384 8393 0 8373 35 31 4 15 0 8 1 mcl64k 65536 310 0 0 34 0 34 34 0 8 0 mcl16k 16384 17 0 0 3 0 3 3 0 8 0 mcl12k 12288 18 0 0 2 0 2 2 0 8 0 mcl9k 9216 15 0 0 2 0 2 2 0 8 0 mcl8k 8192 21 0 0 3 1 2 3 0 8 0 mcl4k 4096 13 0 0 2 0 2 2 0 8 0 mcl2k2 2112 7 0 0 1 0 1 1 0 8 0 mcl2k 2048 195 0 0 23 5 18 23 0 8 0 mtagpl 80 57 0 0 1 0 1 1 0 8 0 mbufpl 256 544 0 0 29 0 29 29 0 8 0 bufpl 256 16650 0 9602 441 0 441 441 0 8 0 anonpl 16 409862 0 388816 175 73 102 102 0 124 16 amapchunkpl 152 23626 0 23456 37 28 9 15 0 158 0 amappl16 192 18289 0 17118 167 96 71 71 0 8 12 amappl15 184 783 0 782 4 3 1 1 0 8 0 amappl14 176 349 0 347 1 0 1 1 0 8 0 amappl13 168 484 0 484 5 5 0 1 0 8 0 amappl12 160 533 0 531 2 1 1 1 0 8 0 amappl11 152 421 0 404 1 0 1 1 0 8 0 amappl10 144 321 0 313 1 0 1 1 0 8 0 amappl9 136 1067 0 1060 1 0 1 1 0 8 0 amappl8 128 644 0 603 2 0 2 2 0 8 0 amappl7 120 390 0 379 1 0 1 1 0 8 0 amappl6 112 398 0 387 1 0 1 1 0 8 0 amappl5 104 833 0 819 1 0 1 1 0 8 0 amappl4 96 3300 0 3264 1 0 1 1 0 8 0 amappl3 88 717 0 710 1 0 1 1 0 8 0 amappl2 80 24703 0 24635 3 1 2 3 0 8 0 amappl1 72 83419 0 82990 25 15 10 20 0 8 0 amappl 80 10739 0 10683 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 64 157 0 28 3 0 3 3 0 8 0 uaddrrnd 24 3282 0 3242 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3282 0 3242 1 0 1 1 0 8 0 vmmpekpl 168 40465 0 40427 3 0 3 3 0 8 0 vmmpepl 168 422387 0 420043 248 108 140 146 0 357 26 vmsppl 368 3257 0 3242 2 0 2 2 0 8 0 pdppl 4096 6571 0 6516 9 1 8 8 0 8 0 pvpl 32 1076677 0 1054000 347 125 222 224 0 265 34 pmappl 232 3281 0 3250 4 2 2 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 698 0 40 20 0 20 20 0 8 1