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 240952 29813 0 0x2 0x4000080 1 syz-fuzzer *171871 65238 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(ffffffff8220951b,ffffffff82206705,2cc,ffffffff8218db71) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd80653da2a8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825343a0) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825343a0) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825343a0) 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(ffffffff8220951b,ffffffff82206705,2cc,ffffffff8218db71) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd80653da2a8) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825343a0) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825343a0) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825343a0) 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 0xffff800020a24db0 rbx 0xffff800020a24e60 rdx 0xffff800020a109e0 rcx 0 rax 0 r8 0xffffffff81d00c7f kprintf+0x16f r9 0x1 r10 0x25 r11 0x743d08a3693323e5 r12 0x3000000008 r13 0xffff800020a24dc0 r14 0x100 r15 0x1 rip 0xffffffff8120bfe8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a24da0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=171871 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020a10c58,0xffff800020a10778 process=0xffff800020a13180 user=0xffff800020a20000, vmspace=0xffffffff82638cc0 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 95875 187407 29813 0 2 0x482 syz-executor.0 46787 454894 29813 0 2 0x2 syz-executor.1 53932 256597 0 0 3 0x14200 acct acct 29918 369029 1 0 3 0x100083 ttyin getty 95019 74719 0 0 3 0x14200 bored sosplice 29813 58550 32847 0 3 0x82 thrsleep syz-fuzzer 29813 195935 32847 0 3 0x4000082 thrsleep syz-fuzzer 29813 262923 32847 0 3 0x4000082 thrsleep syz-fuzzer 29813 282171 32847 0 3 0x4000082 thrsleep syz-fuzzer 29813 321210 32847 0 3 0x4000082 thrsleep syz-fuzzer 29813 240952 32847 0 7 0x4000082 syz-fuzzer 29813 303190 32847 0 3 0x4000082 thrsleep syz-fuzzer 29813 269033 32847 0 3 0x4000082 thrsleep syz-fuzzer 29813 263768 32847 0 3 0x4000082 thrsleep syz-fuzzer 29813 77895 32847 0 3 0x4000082 thrsleep syz-fuzzer 29813 141785 32847 0 3 0x4000082 thrsleep syz-fuzzer 32847 457250 50230 0 3 0x10008a pause ksh 50230 126750 69496 0 3 0x92 select sshd 69496 408918 1 0 3 0x80 select sshd 88709 44074 58852 74 3 0x100092 bpf pflogd 58852 409417 1 0 3 0x80 netio pflogd 50602 448523 68794 73 3 0x100090 kqread syslogd 68794 221393 1 0 3 0x100082 netio syslogd 60100 212917 1 77 3 0x100090 poll dhclient 59680 415477 1 0 3 0x80 poll dhclient 38421 109443 0 0 3 0x14200 pgzero zerothread 1731 273455 0 0 3 0x14200 aiodoned aiodoned 98436 332367 0 0 3 0x14200 syncer update 6241 483819 0 0 3 0x14200 cleaner cleaner 86372 302983 0 0 3 0x14200 reaper reaper 14290 119926 0 0 3 0x14200 pgdaemon pagedaemon 6264 153019 0 0 3 0x14200 bored crynlk 38259 220736 0 0 3 0x14200 bored crypto 51270 510227 0 0 3 0x40014200 acpi0 acpi0 53963 172819 0 0 3 0x40014200 idle1 17424 451589 0 0 3 0x14200 bored softnet 71825 289075 0 0 3 0x14200 bored systqmp 54565 102298 0 0 3 0x14200 bored systq *65238 171871 0 0 7 0x40014200 softclock 63879 370674 0 0 3 0x40014200 idle0 59554 136230 0 0 3 0x14200 bored smr 1 21956 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 65238 (softclock) thread 0xffff800020a109e0 (171871) exclusive rwlock netlock r = 0 (0xffffffff824c0f78) #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 (0xffffffff824d38c0) #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 (0xffffffff82623a10) #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:434 #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 9636 7114K 8209K 78643K 28216 0 0 pcb 13 10K 12K 78643K 2423 0 0 rtable 168 17K 17K 78643K 4371 0 0 ifaddr 122 30K 32K 78643K 1422 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1905 0 0 iov 0 0K 24K 78643K 1701 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1223 77K 77K 78643K 7912 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 111 0 0 VM map 79 39K 39K 78643K 103 0 0 sem 12 0K 1K 78643K 1987 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 4 9K 25K 78643K 7576 0 0 sigio 0 0K 0K 78643K 92 0 0 proc 62 63K 95K 78643K 3185 0 0 subproc 32 2K 2K 78643K 769 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 625 0 0 in_multi 34 2K 2K 78643K 948 0 0 ether_multi 1 0K 0K 78643K 86 0 0 mrt 1 0K 0K 78643K 53 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 1482 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 259 672K 672K 78643K 30394 0 0 UVM aobj 130 9K 9K 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 1715 0 0 NDP 27 0K 1K 78643K 442 0 0 temp 271 3562K 4202K 78643K 215439 0 0 kqueue 0 0K 0K 78643K 80 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 64 113 0 107 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 706 0 704 1 0 1 1 0 8 0 rtentry 112 775 0 709 3 0 3 3 0 8 0 unpcb 120 4786 0 4770 7 6 1 2 0 8 0 syncache 264 43 0 43 19 18 1 1 0 8 1 tcpqe 32 37 0 37 11 10 1 1 0 8 1 tcpcb 544 4389 0 4385 43 42 1 12 0 8 0 inpcb 280 12288 0 12281 51 49 2 9 0 8 1 rttmr 72 16 0 16 12 12 0 1 0 8 0 ip6q 72 13 0 13 8 8 0 1 0 8 0 ip6af 40 27 0 27 8 8 0 1 0 8 0 nd6 48 118 0 116 4 3 1 1 0 8 0 pkpcb 40 54 0 54 20 20 0 1 0 8 0 swfcl 56 5 0 0 1 0 1 1 0 8 0 ppxss 1128 210 0 210 36 35 1 1 0 8 1 pffrag 232 213 0 213 30 30 0 1 0 482 0 pffrnode 88 208 0 208 30 30 0 1 0 8 0 pffrent 40 6974 0 6974 30 30 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 24 957 0 872 1 0 1 1 0 8 0 pfstkey 112 958 0 873 5 2 3 5 0 8 0 pfstate 328 958 0 873 16 7 9 12 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 33 0 27 21 15 6 8 0 8 0 art_heap4 256 3726 0 3436 52 30 22 22 0 8 0 art_table 32 3759 0 3463 4 1 3 3 0 8 0 art_node 16 773 0 717 1 0 1 1 0 8 0 sysvmsgpl 40 42 0 29 2 1 1 1 0 8 0 semupl 112 2 0 2 2 2 0 1 0 8 0 semapl 112 1985 0 1975 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 13291 0 11855 50 3 47 47 0 8 0 ffsino 272 13291 0 11855 97 1 96 96 0 8 0 nchpl 144 25460 0 24985 61 40 21 61 0 8 0 uvmvnodes 72 6829 0 0 125 0 125 125 0 8 0 vnodes 208 6829 0 0 360 0 360 360 0 8 0 namei 1024 93909 0 93909 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 77 0 0 10 0 10 10 0 8 0 vmpool 552 101 0 24 7 1 6 6 0 8 0 scsiplug 64 4 0 4 3 3 0 1 0 8 0 scxspl 192 84778 0 84778 69 65 4 7 0 8 4 plimitpl 152 602 0 594 1 0 1 1 0 8 0 sigapl 432 7646 0 7632 3 1 2 3 0 8 0 futexpl 56 192086 0 192086 2 1 1 1 0 8 1 knotepl 112 1869 0 1850 9 8 1 3 0 8 0 kqueuepl 104 4290 0 4288 7 6 1 4 0 8 0 pipepl 112 17022 0 17003 40 38 2 2 0 8 1 fdescpl 488 7647 0 7632 3 0 3 3 0 8 0 filepl 152 84548 0 84448 60 54 6 14 0 8 2 lockfpl 104 9389 0 9388 1 0 1 1 0 8 0 lockfspl 48 2217 0 2216 1 0 1 1 0 8 0 sessionpl 112 62 0 51 1 0 1 1 0 8 0 pgrppl 48 145 0 134 1 0 1 1 0 8 0 ucredpl 96 7807 0 7797 1 0 1 1 0 8 0 zombiepl 144 7637 0 7636 1 0 1 1 0 8 0 processpl 896 7669 0 7636 4 0 4 4 0 8 0 procpl 632 27178 0 27135 7 2 5 6 0 8 0 srpgc 64 85 0 85 20 20 0 1 0 8 0 sosppl 128 384 0 384 40 40 0 1 0 8 0 sockpl 384 17939 0 17914 97 93 4 15 0 8 0 mcl64k 65536 595 0 0 69 9 60 65 0 8 1 mcl16k 16384 34 0 0 4 1 3 3 0 8 0 mcl12k 12288 36 0 0 2 0 2 2 0 8 0 mcl9k 9216 26 0 0 2 0 2 2 0 8 1 mcl8k 8192 25 0 0 4 1 3 3 0 8 0 mcl4k 4096 49 0 0 3 0 3 3 0 8 0 mcl2k2 2112 8 0 0 1 0 1 1 0 8 0 mcl2k 2048 184 0 0 20 6 14 20 0 8 0 mtagpl 80 126 0 0 1 0 1 1 0 8 0 mbufpl 256 1232 0 0 45 0 45 45 0 8 0 bufpl 256 35220 0 28162 442 0 442 442 0 8 0 anonpl 16 968159 0 947212 265 171 94 105 0 124 0 amapchunkpl 152 63274 0 63096 142 134 8 21 0 158 0 amappl16 192 43564 0 42339 309 246 63 74 0 8 0 amappl15 184 1022 0 1022 5 5 0 1 0 8 0 amappl14 176 1158 0 1149 1 0 1 1 0 8 0 amappl13 168 419 0 418 7 6 1 1 0 8 0 amappl12 160 1217 0 1216 1 0 1 1 0 8 0 amappl11 152 1323 0 1307 1 0 1 1 0 8 0 amappl10 144 918 0 912 1 0 1 1 0 8 0 amappl9 136 2413 0 2409 1 0 1 1 0 8 0 amappl8 128 1980 0 1912 4 1 3 3 0 8 0 amappl7 120 1144 0 1135 1 0 1 1 0 8 0 amappl6 112 1206 0 1192 1 0 1 1 0 8 0 amappl5 104 1767 0 1752 1 0 1 1 0 8 0 amappl4 96 7157 0 7120 2 1 1 2 0 8 0 amappl3 88 1789 0 1765 1 0 1 1 0 8 0 amappl2 80 58785 0 58719 3 1 2 3 0 8 0 amappl1 72 186577 0 186156 26 16 10 20 0 8 0 amappl 80 28277 0 28189 3 0 3 3 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 7748 0 7632 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 7748 0 7632 1 0 1 1 0 8 0 vmmpekpl 168 91451 0 91405 3 0 3 3 0 8 0 vmmpepl 168 997508 0 995016 632 475 157 163 0 357 34 vmsppl 368 7646 0 7632 2 0 2 2 0 8 0 pdppl 4096 15503 0 15389 21 6 15 15 0 8 0 pvpl 32 2491195 0 2468233 619 418 201 235 0 265 3 pmappl 232 7747 0 7656 7 1 6 6 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 832 0 115 21 0 21 21 0 8 0