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 154757 33226 0 0x2 0x480 1 syz-executor.0 *414413 46541 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(ffffffff8220716b,ffffffff822041ce,2cc,ffffffff8218d0e4) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd806475c2a8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff8256f730) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff8256f730) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff8256f730) 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(ffffffff8220716b,ffffffff822041ce,2cc,ffffffff8218d0e4) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd806475c2a8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff8256f730) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff8256f730) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff8256f730) 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 0xffff800020a253d0 rbx 0xffff800020a25480 rdx 0xffff800020a10ed0 rcx 0 rax 0 r8 0xffffffff8150e41f kprintf+0x16f r9 0x1 r10 0x25 r11 0xb58b11434bfe3f7 r12 0x3000000008 r13 0xffff800020a253e0 r14 0x100 r15 0x1 rip 0xffffffff814f2878 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a253c0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=414413 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020a11148,0xffff800020a10c68 process=0xffff800020a12000 user=0xffff800020a20000, vmspace=0xffffffff82626068 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 46600 224422 33226 0 2 0 syz-executor.0 46600 286140 33226 0 2 0x4000000 syz-executor.0 53897 185025 7299 0 2 0 syz-executor.1 53897 489518 7299 0 2 0x4000000 syz-executor.1 7299 75698 39775 0 2 0x482 syz-executor.1 33226 154757 39775 0 7 0x482 syz-executor.0 93387 490899 0 0 3 0x14200 bored sosplice 39775 79349 93134 0 3 0x82 thrsleep syz-fuzzer 39775 411154 93134 0 2 0x4000482 syz-fuzzer 39775 465413 93134 0 3 0x4000082 thrsleep syz-fuzzer 39775 86664 93134 0 3 0x4000082 thrsleep syz-fuzzer 39775 91210 93134 0 3 0x4000082 thrsleep syz-fuzzer 39775 184164 93134 0 2 0x4000482 syz-fuzzer 39775 416615 93134 0 3 0x4000082 kqread syz-fuzzer 39775 443741 93134 0 3 0x4000082 thrsleep syz-fuzzer 39775 256861 93134 0 3 0x4000082 thrsleep syz-fuzzer 39775 136183 93134 0 2 0x4000482 syz-fuzzer 93134 216798 83719 0 3 0x10008a pause ksh 83719 100537 79416 0 3 0x92 select sshd 60891 225963 1 0 3 0x100083 ttyin getty 79416 362296 1 0 3 0x80 select sshd 51322 330159 12857 74 2 0x100492 pflogd 12857 521347 1 0 3 0x80 netio pflogd 88987 185363 58937 73 3 0x100090 kqread syslogd 58937 195339 1 0 3 0x100082 netio syslogd 68811 195503 1 77 3 0x100090 poll dhclient 77449 184428 1 0 3 0x80 poll dhclient 82391 133139 0 0 2 0x14200 zerothread 37699 523997 0 0 3 0x14200 aiodoned aiodoned 70493 507952 0 0 2 0x14200 update 99501 322306 0 0 3 0x14200 cleaner cleaner 67030 195008 0 0 3 0x14200 reaper reaper 15613 355131 0 0 3 0x14200 pgdaemon pagedaemon 87301 409867 0 0 3 0x14200 bored crynlk 23897 154587 0 0 3 0x14200 bored crypto 16136 373215 0 0 3 0x40014200 acpi0 acpi0 65529 59397 0 0 3 0x40014200 idle1 13971 340909 0 0 2 0x14200 softnet 95476 281925 0 0 2 0x14200 systqmp 62792 448670 0 0 3 0x14200 bored systq *46541 414413 0 0 7 0x40014200 softclock 19915 256502 0 0 3 0x40014200 idle0 76191 106179 0 0 3 0x14200 bored smr 1 266493 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 46541 (softclock) thread 0xffff800020a10ed0 (414413) exclusive rwlock netlock r = 0 (0xffffffff8247ea78) #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 (0xffffffff824cc170) #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 (0xffffffff826567d8) #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:441 #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 9563 6433K 12798K 78643K 32462 0 0 pcb 13 13K 15K 78643K 463 0 0 rtable 103 4K 5K 78643K 1671 0 0 ifaddr 81 18K 18K 78643K 468 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1591 0 0 iov 0 0K 24K 78643K 472 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1300 82K 82K 78643K 6705 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 45 0 0 VM map 17 8K 8K 78643K 27 0 0 sem 12 0K 1K 78643K 1210 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 25K 78643K 2308 0 0 sigio 0 0K 0K 78643K 18 0 0 proc 62 63K 83K 78643K 1176 0 0 subproc 32 2K 2K 78643K 276 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 198 0 0 in_multi 29 2K 2K 78643K 325 0 0 ether_multi 1 0K 0K 78643K 29 0 0 mrt 0 0K 0K 78643K 8 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 66 291K 291K 78643K 66 0 0 exec 0 0K 1K 78643K 572 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 142 153K 153K 78643K 9321 0 0 UVM aobj 130 6K 6K 78643K 134 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 507 0 0 NDP 17 0K 0K 78643K 143 0 0 temp 207 3560K 4200K 78643K 81578 0 0 kqueue 0 0K 0K 78643K 24 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 76 0 69 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 203 0 201 1 0 1 1 0 8 0 rtentry 112 320 0 280 2 0 2 2 0 8 0 unpcb 120 2073 0 2059 4 3 1 2 0 8 0 syncache 264 10 0 10 4 4 0 1 0 8 0 sackhl 24 4 0 4 3 3 0 1 0 8 0 tcpqe 32 2 0 2 1 1 0 1 0 8 0 tcpcb 544 1341 0 1337 13 12 1 13 0 8 0 inpcb 280 4934 0 4927 30 28 2 13 0 8 1 rttmr 72 4 0 3 3 2 1 1 0 8 0 nd6 48 43 0 40 1 0 1 1 0 8 0 pkpcb 40 12 0 12 3 3 0 1 0 8 0 swfcl 56 3 0 0 1 0 1 1 0 8 0 ppxss 1128 54 0 54 9 8 1 1 0 8 1 pffrag 232 62 0 62 9 8 1 1 0 482 1 pffrnode 88 62 0 62 9 8 1 1 0 8 1 pffrent 40 1916 0 1916 9 8 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 24 225 0 182 1 0 1 1 0 8 0 pfstkey 112 225 0 182 3 0 3 3 0 8 0 pfstate 328 225 0 182 8 3 5 8 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1320 0 1076 26 9 17 18 0 8 0 art_table 32 1321 0 1076 3 0 3 3 0 8 0 art_node 16 319 0 280 1 0 1 1 0 8 0 sysvmsgpl 40 47 0 24 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 1208 0 1198 1 0 1 1 0 8 0 shmpl 112 132 0 4 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 4850 0 3447 46 0 46 46 0 8 0 ffsino 272 4850 0 3447 96 2 94 95 0 8 0 nchpl 144 8511 0 6894 61 0 61 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 32605 0 32605 4 3 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 15 0 0 2 0 2 2 0 8 0 vmpool 552 25 0 10 2 0 2 2 0 8 0 scsiplug 64 4 0 4 3 2 1 1 0 8 1 scxspl 192 30635 0 30635 30 28 2 7 0 8 2 plimitpl 152 224 0 216 1 0 1 1 0 8 0 sigapl 432 2466 0 2450 3 1 2 3 0 8 0 futexpl 56 61160 0 61160 3 2 1 1 0 8 1 knotepl 112 633 0 614 1 0 1 1 0 8 0 kqueuepl 104 614 0 612 4 3 1 4 0 8 0 pipepl 112 2538 0 2519 9 7 2 2 0 8 1 fdescpl 488 2467 0 2450 3 0 3 3 0 8 0 filepl 152 25879 0 25776 41 34 7 13 0 8 3 lockfpl 104 1238 0 1237 1 0 1 1 0 8 0 lockfspl 48 418 0 417 1 0 1 1 0 8 0 sessionpl 112 32 0 21 1 0 1 1 0 8 0 pgrppl 48 76 0 65 1 0 1 1 0 8 0 ucredpl 96 2255 0 2246 1 0 1 1 0 8 0 zombiepl 144 2453 0 2453 5 4 1 1 0 8 1 processpl 896 2486 0 2453 4 0 4 4 0 8 0 procpl 632 7761 0 7717 5 0 5 5 0 8 0 srpgc 64 18 0 18 9 9 0 1 0 8 0 sosppl 128 313 0 313 5 4 1 1 0 8 1 sockpl 384 7287 0 7264 48 44 4 22 0 8 0 mcl64k 65536 267 0 0 34 12 22 34 0 8 1 mcl16k 16384 11 0 0 2 0 2 2 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 17 0 0 2 0 2 2 0 8 0 mcl8k 8192 18 0 0 3 0 3 3 0 8 0 mcl4k 4096 25 0 0 4 1 3 3 0 8 0 mcl2k2 2112 4 0 0 1 0 1 1 0 8 0 mcl2k 2048 173 0 0 19 3 16 19 0 8 0 mtagpl 80 59 0 0 1 0 1 1 0 8 0 mbufpl 256 884 0 0 45 0 45 45 0 8 0 bufpl 256 15091 0 8043 441 0 441 441 0 8 0 anonpl 16 325865 0 310511 151 68 83 92 0 124 5 amapchunkpl 152 19397 0 19249 52 43 9 14 0 158 1 amappl16 192 14025 0 12992 130 75 55 64 0 8 3 amappl15 184 633 0 633 3 2 1 1 0 8 1 amappl14 176 389 0 386 1 0 1 1 0 8 0 amappl13 168 33 0 33 2 2 0 1 0 8 0 amappl12 160 275 0 273 4 3 1 1 0 8 0 amappl11 152 530 0 515 1 0 1 1 0 8 0 amappl10 144 143 0 135 1 0 1 1 0 8 0 amappl9 136 1197 0 1190 1 0 1 1 0 8 0 amappl8 128 759 0 724 2 0 2 2 0 8 0 amappl7 120 208 0 200 1 0 1 1 0 8 0 amappl6 112 523 0 512 1 0 1 1 0 8 0 amappl5 104 522 0 506 1 0 1 1 0 8 0 amappl4 96 2305 0 2274 1 0 1 1 0 8 0 amappl3 88 992 0 987 1 0 1 1 0 8 0 amappl2 80 18327 0 18245 3 1 2 3 0 8 0 amappl1 72 65264 0 64817 26 16 10 20 0 8 0 amappl 80 8313 0 8259 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 64 133 0 4 3 0 3 3 0 8 0 uaddrrnd 24 2492 0 2450 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2492 0 2450 1 0 1 1 0 8 0 vmmpekpl 168 24993 0 24956 3 1 2 2 0 8 0 vmmpepl 168 322099 0 319782 256 119 137 141 0 357 32 vmsppl 368 2466 0 2450 2 0 2 2 0 8 0 pdppl 4096 4991 0 4935 13 5 8 8 0 8 0 pvpl 32 867250 0 848750 308 102 206 214 0 265 29 pmappl 232 2491 0 2460 2 0 2 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 710 0 50 19 0 19 19 0 8 0