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 70940 88307 0 0 0x480 1 syz-executor.0 *376824 5609 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(ffffffff8220896d,ffffffff822055fb,2cc,ffffffff8218e22c) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd8067243948) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825518d8) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825518d8) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825518d8) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a11148) 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(ffffffff8220896d,ffffffff822055fb,2cc,ffffffff8218e22c) at __assert+0x2b sys/kern/subr_prf.c:154 arptfree(fffffd8067243948) at arptfree+0xfb sys/netinet/if_ether.c:716 arptimer(ffffffff825518d8) at arptimer+0x95 sys/netinet/if_ether.c:120 timeout_run(ffffffff825518d8) at timeout_run+0xc4 timeout_sync_leave sys/kern/kern_timeout.c:177 [inline] timeout_run(ffffffff825518d8) at timeout_run+0xc4 sys/kern/kern_timeout.c:474 softclock_thread(ffff800020a11148) 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 0xffff800020a25b20 rbx 0xffff800020a25bd0 rdx 0xffff800020a11148 rcx 0 rax 0 r8 0xffffffff814afb0f kprintf+0x16f r9 0x1 r10 0x25 r11 0xa7346371b22ae92b r12 0x3000000008 r13 0xffff800020a25b30 r14 0x100 r15 0x1 rip 0xffffffff81bf2868 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a25b10 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=376824 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff800020a11638,0xffff800020a10778 process=0xffff800020a12000 user=0xffff800020a20000, vmspace=0xffffffff82660f08 estcpu=1, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 88307 70940 70819 0 7 0x480 syz-executor.0 88307 389152 70819 0 3 0x4000080 select syz-executor.0 88307 406189 70819 0 3 0x4000080 fsleep syz-executor.0 45420 221331 77266 0 3 0x82 piperd syz-executor.1 70819 260354 77266 0 2 0x482 syz-executor.0 35741 12159 1 0 3 0x100083 ttyin getty 57357 302982 0 0 3 0x14200 acct acct 6105 75948 0 0 3 0x14200 bored sosplice 77266 266642 39532 0 3 0x82 thrsleep syz-fuzzer 77266 241248 39532 0 3 0x4000082 thrsleep syz-fuzzer 77266 477888 39532 0 3 0x4000082 thrsleep syz-fuzzer 77266 510219 39532 0 3 0x4000082 thrsleep syz-fuzzer 77266 429925 39532 0 3 0x4000082 thrsleep syz-fuzzer 77266 138988 39532 0 3 0x4000082 thrsleep syz-fuzzer 77266 80666 39532 0 3 0x4000082 thrsleep syz-fuzzer 77266 153941 39532 0 3 0x4000082 thrsleep syz-fuzzer 77266 325189 39532 0 3 0x4000082 thrsleep syz-fuzzer 77266 521023 39532 0 3 0x4000082 kqread syz-fuzzer 77266 225812 39532 0 3 0x4000082 thrsleep syz-fuzzer 39532 353504 84586 0 3 0x10008a pause ksh 84586 141517 23611 0 3 0x92 select sshd 23611 107715 1 0 3 0x80 select sshd 56430 160133 41709 74 3 0x100092 bpf pflogd 41709 285458 1 0 3 0x80 netio pflogd 81547 453741 52979 73 3 0x100090 kqread syslogd 52979 142461 1 0 3 0x100082 netio syslogd 15595 129117 1 77 3 0x100090 poll dhclient 60277 286329 1 0 3 0x80 poll dhclient 56035 103988 0 0 3 0x14200 pgzero zerothread 82673 146704 0 0 3 0x14200 aiodoned aiodoned 89711 66898 0 0 3 0x14200 syncer update 44104 464504 0 0 3 0x14200 cleaner cleaner 87247 60925 0 0 3 0x14200 reaper reaper 13546 165633 0 0 3 0x14200 pgdaemon pagedaemon 58591 218955 0 0 3 0x14200 bored crynlk 65148 125172 0 0 3 0x14200 bored crypto 99036 330550 0 0 3 0x40014200 acpi0 acpi0 50154 15809 0 0 3 0x40014200 idle1 40208 438978 0 0 3 0x14200 bored softnet 24427 383661 0 0 3 0x14200 bored systqmp 70729 253875 0 0 3 0x14200 bored systq * 5609 376824 0 0 7 0x40014200 softclock 58208 33801 0 0 3 0x40014200 idle0 5422 317997 0 0 3 0x14200 bored smr 1 289688 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 5609 (softclock) thread 0xffff800020a11148 (376824) exclusive rwlock netlock r = 0 (0xffffffff82474be8) #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 (0xffffffff8247d4d0) #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 (0xffffffff82669b48) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 __mp_acquire_count+0x51 sys/kern/kern_lock.c:227 #2 mi_switch+0x397 sys/kern/sched_bsd.c:435 #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 9664 7119K 9381K 78643K 95990 0 0 pcb 14 13K 15K 78643K 6169 0 0 rtable 202 19K 20K 78643K 9332 0 0 ifaddr 141 38K 43K 78643K 2844 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 2454 0 0 iov 0 0K 32K 78643K 3321 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1223 77K 79K 78643K 27032 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 178 0 0 VM map 106 53K 53K 78643K 176 0 0 sem 12 0K 0K 78643K 3358 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 15457 0 0 sigio 0 0K 0K 78643K 162 0 0 proc 62 63K 95K 78643K 6102 0 0 subproc 32 2K 2K 78643K 1725 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 1068 0 0 in_multi 48 3K 3K 78643K 1979 0 0 ether_multi 1 0K 0K 78643K 196 0 0 mrt 5 0K 0K 78643K 145 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 174 768K 768K 78643K 174 0 0 exec 0 0K 1K 78643K 3134 0 0 pfkey data 0 0K 4K 78643K 3 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 322 853K 853K 78643K 55968 0 0 UVM aobj 130 8K 8K 78643K 138 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 2 0K 2K 78643K 3683 0 0 NDP 27 0K 1K 78643K 916 0 0 temp 280 3566K 4206K 78643K 288794 0 0 kqueue 0 0K 0K 78643K 155 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 64 217 0 212 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 1263 0 1261 1 0 1 1 0 8 0 rtentry 112 1690 0 1607 4 1 3 3 0 8 0 unpcb 120 20283 0 20255 26 24 2 2 0 8 0 syncache 264 84 0 84 42 41 1 1 0 8 1 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 115 0 115 20 19 1 1 0 8 1 tcpcb 544 6851 0 6847 59 57 2 13 0 8 1 ipq 40 6 0 6 6 6 0 1 0 8 0 ipqe 40 12 0 12 6 6 0 1 0 8 0 inpcb 280 39647 0 39638 111 106 5 13 0 8 4 rttmr 72 50 0 49 6 5 1 1 0 8 0 ip6q 72 11 0 11 5 5 0 1 0 8 0 ip6af 40 26 0 26 4 4 0 1 0 8 0 nd6 48 247 0 245 12 11 1 1 0 8 0 pkpcb 40 136 0 136 28 28 0 1 0 8 0 swfcl 56 8 0 0 1 0 1 1 0 8 0 ppxss 1128 372 0 372 53 52 1 1 0 8 1 pffrag 232 384 0 382 42 41 1 1 0 482 0 pffrnode 88 383 0 382 42 41 1 1 0 8 0 pffrent 40 12831 0 12807 42 41 1 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 1305 0 1211 1 0 1 1 0 8 0 pfstkey 112 1305 0 1211 5 2 3 3 0 8 0 pfstate 328 1305 0 1210 17 8 9 9 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 16 0 8 14 6 8 9 0 8 0 art_heap4 256 7077 0 6761 86 63 23 24 0 8 1 art_table 32 7093 0 6769 11 7 4 4 0 8 0 art_node 16 1676 0 1620 1 0 1 1 0 8 0 sysvmsgpl 40 75 0 44 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 3356 0 3346 1 0 1 1 0 8 0 shmpl 112 136 0 8 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 25343 0 23874 49 1 48 48 0 8 0 ffsino 272 25343 0 23874 100 1 99 99 0 8 0 nchpl 144 49215 0 48710 63 43 20 61 0 8 0 uvmvnodes 72 7899 0 0 144 0 144 144 0 8 0 vnodes 208 7899 0 0 416 0 416 416 0 8 0 namei 1024 197745 0 197745 9 8 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 104 0 0 13 0 13 13 0 8 0 vmpool 552 174 0 70 14 6 8 8 0 8 0 scsiplug 64 22 0 22 18 17 1 1 0 8 1 scxspl 192 155148 0 155148 121 118 3 7 0 8 3 plimitpl 152 1315 0 1307 1 0 1 1 0 8 0 sigapl 432 15366 0 15351 4 2 2 3 0 8 0 futexpl 56 464774 0 464773 4 3 1 1 0 8 0 knotepl 112 3752 0 3733 20 18 2 3 0 8 1 kqueuepl 104 4919 0 4917 17 15 2 4 0 8 1 pipepl 112 9420 0 9401 17 16 1 2 0 8 0 fdescpl 488 15367 0 15351 3 0 3 3 0 8 0 filepl 152 172673 0 172570 124 115 9 14 0 8 4 lockfpl 104 4988 0 4987 1 0 1 1 0 8 0 lockfspl 48 1760 0 1759 1 0 1 1 0 8 0 sessionpl 112 125 0 114 1 0 1 1 0 8 0 pgrppl 48 290 0 279 1 0 1 1 0 8 0 ucredpl 96 26809 0 26799 1 0 1 1 0 8 0 zombiepl 144 15354 0 15354 7 6 1 1 0 8 1 processpl 896 15387 0 15354 5 1 4 5 0 8 0 procpl 632 49805 0 49760 5 0 5 5 0 8 0 srpgc 64 186 0 186 45 45 0 1 0 8 0 sosppl 128 339 0 339 52 51 1 1 0 8 1 sockpl 384 61869 0 61830 188 176 12 23 0 8 7 mcl64k 65536 955 0 0 96 40 56 65 0 8 2 mcl16k 16384 89 0 0 11 8 3 3 0 8 0 mcl12k 12288 49 0 0 2 0 2 2 0 8 0 mcl9k 9216 68 0 0 4 2 2 2 0 8 0 mcl8k 8192 41 0 0 4 1 3 3 0 8 0 mcl4k 4096 49 0 0 5 2 3 3 0 8 0 mcl2k2 2112 17 0 0 2 0 2 2 0 8 0 mcl2k 2048 279 0 0 23 13 10 23 0 8 0 mtagpl 80 175 0 0 1 0 1 1 0 8 0 mbufpl 256 1839 0 0 46 0 46 46 0 8 0 bufpl 256 57656 0 49739 496 0 496 496 0 8 0 anonpl 16 1796194 0 1776005 426 328 98 101 0 124 12 amapchunkpl 152 116521 0 116339 213 204 9 21 0 158 0 amappl16 192 80154 0 78962 501 432 69 72 0 8 8 amappl15 184 2414 0 2412 1 0 1 1 0 8 0 amappl14 176 1950 0 1943 1 0 1 1 0 8 0 amappl13 168 1106 0 1105 12 11 1 1 0 8 0 amappl12 160 2148 0 2148 13 13 0 1 0 8 0 amappl11 152 2659 0 2642 1 0 1 1 0 8 0 amappl10 144 2545 0 2539 1 0 1 1 0 8 0 amappl9 136 4942 0 4938 1 0 1 1 0 8 0 amappl8 128 4640 0 4551 5 2 3 4 0 8 0 amappl7 120 2861 0 2849 1 0 1 1 0 8 0 amappl6 112 2396 0 2377 1 0 1 1 0 8 0 amappl5 104 3503 0 3490 1 0 1 1 0 8 0 amappl4 96 15248 0 15199 9 7 2 2 0 8 0 amappl3 88 3272 0 3255 1 0 1 1 0 8 0 amappl2 80 117567 0 117483 4 2 2 3 0 8 0 amappl1 72 353097 0 352665 25 15 10 20 0 8 0 amappl 80 52041 0 51935 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 64 137 0 8 3 0 3 3 0 8 0 uaddrrnd 24 15541 0 15351 2 0 2 2 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 15541 0 15351 2 0 2 2 0 8 0 vmmpekpl 168 114474 0 114413 3 0 3 3 0 8 0 vmmpepl 168 1974983 0 1972361 775 624 151 163 0 357 25 vmsppl 368 15366 0 15351 2 0 2 2 0 8 0 pdppl 4096 31089 0 30946 25 6 19 19 0 8 0 pvpl 32 4724880 0 4701959 853 629 224 234 0 265 26 pmappl 232 15540 0 15421 13 5 8 8 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 983 0 208 24 1 23 23 0 8 0