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 268834 95706 0 0x2 0x4000480 1 syz-fuzzer *286815 18754 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(ffffffff82207cf2,ffffffff822030c1,2cc,ffffffff8218ca66) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd8064db0008) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825cfe88) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825cfe88) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825cfe88) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a10c58) 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(ffffffff82207cf2,ffffffff822030c1,2cc,ffffffff8218ca66) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd8064db0008) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825cfe88) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825cfe88) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825cfe88) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a10c58) 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 0xffff800020a25010 rbx 0xffff800020a250c0 rdx 0xffff800020a10c58 rcx 0 rax 0 r8 0xffffffff814de02f kprintf+0x16f r9 0x1 r10 0x25 r11 0x466774e9a38154e1 r12 0x3000000008 r13 0xffff800020a25020 r14 0x100 r15 0x1 rip 0xffffffff820cd6c8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a25000 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=286815 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020a11148,0xffff800020a109f0 process=0xffff800020a12a80 user=0xffff800020a20000, vmspace=0xffffffff82637328 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 34362 468839 64789 0 2 0 syz-executor.1 34362 155978 64789 0 2 0x4000000 syz-executor.1 67964 177998 26680 0 2 0 syz-executor.0 67964 369514 26680 0 3 0x4000080 lockf syz-executor.0 64789 448704 95706 0 2 0x2 syz-executor.1 26680 524044 95706 0 2 0x482 syz-executor.0 91341 417306 1 0 3 0x100083 ttyopn getty 59264 137544 0 0 3 0x14200 acct acct 92109 160137 0 0 3 0x14200 bored sosplice 95706 399902 85051 0 3 0x82 thrsleep syz-fuzzer 95706 406571 85051 0 3 0x4000082 thrsleep syz-fuzzer 95706 115760 85051 0 3 0x4000082 thrsleep syz-fuzzer 95706 424177 85051 0 3 0x4000082 thrsleep syz-fuzzer 95706 5931 85051 0 3 0x4000082 thrsleep syz-fuzzer 95706 291264 85051 0 3 0x4000082 kqread syz-fuzzer 95706 244664 85051 0 3 0x4000082 thrsleep syz-fuzzer 95706 492455 85051 0 3 0x4000082 thrsleep syz-fuzzer 95706 268834 85051 0 7 0x4000482 syz-fuzzer 95706 182369 85051 0 3 0x4000082 thrsleep syz-fuzzer 85051 259031 72036 0 3 0x10008a pause ksh 72036 287292 14011 0 3 0x92 select sshd 14011 292949 1 0 3 0x80 select sshd 82023 13007 52437 74 2 0x100492 pflogd 52437 159539 1 0 3 0x80 netio pflogd 76131 422370 81783 73 2 0x100090 syslogd 81783 16320 1 0 3 0x100082 netio syslogd 97313 158906 1 77 3 0x100090 poll dhclient 31188 368749 1 0 3 0x80 poll dhclient 70483 135031 0 0 2 0x14200 zerothread 97742 144389 0 0 3 0x14200 aiodoned aiodoned 14860 268678 0 0 2 0x14200 update 92898 227647 0 0 3 0x14200 cleaner cleaner 16930 40190 0 0 3 0x14200 reaper reaper 55242 126515 0 0 3 0x14200 pgdaemon pagedaemon 24456 423823 0 0 3 0x14200 bored crynlk 19310 163415 0 0 3 0x14200 bored crypto 93491 482630 0 0 3 0x40014200 acpi0 acpi0 19200 140341 0 0 3 0x40014200 idle1 98264 197666 0 0 2 0x14200 softnet 22273 386237 0 0 2 0x14200 systqmp 39006 205129 0 0 3 0x14200 bored systq *18754 286815 0 0 7 0x40014200 softclock 22843 339518 0 0 3 0x40014200 idle0 52539 121180 0 0 3 0x14200 bored smr 1 172106 0 0 3 0x82 wait init 0 0 -1 0 2 0x10200 swapper ddb{0}> show all locks Process 18754 (softclock) thread 0xffff800020a10c58 (286815) exclusive rwlock netlock r = 0 (0xffffffff824fc348) #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 (0xffffffff82493ae0) #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 (0xffffffff82622388) #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 9591 6463K 8071K 78643K 17239 0 0 pcb 13 8K 9K 78643K 644 0 0 rtable 130 14K 17K 78643K 2190 0 0 ifaddr 91 20K 22K 78643K 608 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1674 0 0 iov 0 0K 24K 78643K 612 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1227 77K 77K 78643K 3808 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 93 0 0 VM map 30 15K 15K 78643K 40 0 0 sem 12 0K 1K 78643K 683 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 25K 78643K 3211 0 0 sigio 0 0K 0K 78643K 30 0 0 proc 61 63K 95K 78643K 1708 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 344 0 0 in_multi 36 2K 2K 78643K 401 0 0 ether_multi 1 0K 0K 78643K 26 0 0 mrt 0 0K 0K 78643K 18 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 712 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 167 251K 253K 78643K 12477 0 0 UVM aobj 130 4K 4K 78643K 254 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 609 0 0 NDP 21 0K 0K 78643K 195 0 0 temp 236 3561K 4201K 78643K 118916 0 0 kqueue 0 0K 0K 78643K 39 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 78 0 71 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 309 0 307 1 0 1 1 0 8 0 rtentry 112 403 0 357 2 0 2 2 0 8 0 unpcb 120 3509 0 3498 3 2 1 2 0 8 0 syncache 264 14 0 14 7 7 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 69 0 69 5 5 0 1 0 8 0 tcpcb 544 1094 0 1090 2 1 1 2 0 8 0 inpcb 280 3589 0 3581 12 11 1 3 0 8 0 rttmr 72 6 0 6 6 6 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 59 0 55 1 0 1 1 0 8 0 pkpcb 40 24 0 24 4 4 0 1 0 8 0 swfcl 56 4 0 0 1 0 1 1 0 8 0 ppxss 1128 66 0 66 10 9 1 1 0 8 1 pffrag 232 62 0 62 10 10 0 1 0 482 0 pffrnode 88 62 0 62 10 10 0 1 0 8 0 pffrent 40 1476 0 1476 10 10 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 24 224 0 184 1 0 1 1 0 8 0 pfstkey 112 224 0 184 2 0 2 2 0 8 0 pfstate 328 224 0 184 6 1 5 6 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 5 0 4 3 2 1 3 0 8 0 art_heap4 256 1767 0 1535 24 8 16 17 0 8 1 art_table 32 1772 0 1539 3 0 3 3 0 8 0 art_node 16 400 0 358 1 0 1 1 0 8 0 sysvmsgpl 40 55 0 35 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 677 0 667 1 0 1 1 0 8 0 shmpl 112 252 0 124 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 6540 0 5122 46 0 46 46 0 8 0 ffsino 272 6540 0 5122 95 0 95 95 0 8 0 nchpl 144 11728 0 11273 61 40 21 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 41630 0 41630 1 0 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 38 0 10 3 1 2 2 0 8 0 scsiplug 64 8 0 8 4 4 0 1 0 8 0 scxspl 192 43518 0 43518 27 24 3 7 0 8 3 plimitpl 152 280 0 272 1 0 1 1 0 8 0 sigapl 432 3349 0 3333 4 2 2 3 0 8 0 futexpl 56 70390 0 70390 1 0 1 1 0 8 1 knotepl 112 892 0 873 2 1 1 2 0 8 0 kqueuepl 104 906 0 903 1 0 1 1 0 8 0 pipepl 112 2212 0 2193 5 4 1 2 0 8 0 fdescpl 488 3350 0 3333 3 0 3 3 0 8 0 filepl 152 29011 0 28904 18 13 5 7 0 8 0 lockfpl 104 1280 0 1277 1 0 1 1 0 8 0 lockfspl 48 399 0 397 1 0 1 1 0 8 0 sessionpl 112 40 0 29 1 0 1 1 0 8 0 pgrppl 48 70 0 59 1 0 1 1 0 8 0 ucredpl 96 4116 0 4106 1 0 1 1 0 8 0 zombiepl 144 3337 0 3337 1 0 1 1 0 8 1 processpl 896 3371 0 3337 5 1 4 5 0 8 0 procpl 632 10619 0 10574 5 0 5 5 0 8 1 srpgc 64 36 0 36 12 11 1 1 0 8 1 sosppl 128 50 0 50 11 11 0 1 0 8 0 sockpl 384 7465 0 7444 13 9 4 7 0 8 1 mcl64k 65536 23 0 0 3 0 3 3 0 8 0 mcl16k 16384 9 0 0 2 0 2 2 0 8 0 mcl12k 12288 28 0 0 2 0 2 2 0 8 0 mcl9k 9216 9 0 0 1 0 1 1 0 8 0 mcl8k 8192 17 0 0 3 1 2 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 175 0 0 21 1 20 21 0 8 0 mtagpl 80 46 0 0 1 0 1 1 0 8 0 mbufpl 256 616 0 0 28 0 28 28 0 8 0 bufpl 256 16389 0 9341 441 0 441 441 0 8 0 anonpl 16 415759 0 397347 139 44 95 96 0 124 15 amapchunkpl 152 24660 0 24506 56 42 14 14 0 158 7 amappl16 192 18168 0 17063 141 77 64 68 0 8 8 amappl15 184 105 0 104 1 0 1 1 0 8 0 amappl14 176 502 0 496 1 0 1 1 0 8 0 amappl13 168 598 0 597 1 0 1 1 0 8 0 amappl12 160 887 0 886 1 0 1 1 0 8 0 amappl11 152 929 0 914 1 0 1 1 0 8 0 amappl10 144 17 0 14 1 0 1 1 0 8 0 amappl9 136 962 0 956 1 0 1 1 0 8 0 amappl8 128 491 0 451 3 1 2 2 0 8 0 amappl7 120 137 0 128 1 0 1 1 0 8 0 amappl6 112 927 0 917 1 0 1 1 0 8 0 amappl5 104 1184 0 1167 1 0 1 1 0 8 0 amappl4 96 3512 0 3477 1 0 1 1 0 8 0 amappl3 88 1196 0 1187 1 0 1 1 0 8 0 amappl2 80 24721 0 24635 3 1 2 3 0 8 0 amappl1 72 87378 0 86924 25 15 10 20 0 8 0 amappl 80 11269 0 11204 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 64 253 0 124 3 0 3 3 0 8 0 uaddrrnd 24 3388 0 3333 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3388 0 3333 1 0 1 1 0 8 0 vmmpekpl 168 30720 0 30682 3 0 3 3 0 8 0 vmmpepl 168 438775 0 436311 256 112 144 151 0 357 34 vmsppl 368 3349 0 3333 2 0 2 2 0 8 0 pdppl 4096 6783 0 6714 10 1 9 9 0 8 0 pvpl 32 1105522 0 1084855 308 95 213 216 0 265 31 pmappl 232 3387 0 3343 4 1 3 3 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 645 0 17 18 0 18 18 0 8 0