panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/setuid/kernel/sys/netinet/if_ether.c", line 776 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 262587 87981 32767 0x10 0 1 syz-executor.4 *311060 33335 0 0x14000 0x40000200 0K softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff825a8806) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff82622986,ffffffff8266806e,308,ffffffff8257a351) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807ab11018) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff829f9478) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff829f9478) at timeout_run+0xcc sys/kern/kern_timeout.c:641 softclock_thread(ffff8000211e9500) at softclock_thread+0x134 sys/kern/kern_timeout.c:765 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 *cpu0: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/setuid/kernel/sys/netinet/if_ether.c", line 776 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff825a8806) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff82622986,ffffffff8266806e,308,ffffffff8257a351) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807ab11018) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff829f9478) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff829f9478) at timeout_run+0xcc sys/kern/kern_timeout.c:641 softclock_thread(ffff8000211e9500) at softclock_thread+0x134 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff8000211f57d0 rbx 0xffffffff829e6b8f cpu_info_full_primary+0x2b8f rdx 0 rcx 0 rax 0xffff8000211e9500 r8 0x101010101010101 r9 0x8080808080808080 r10 0x9110c8f792ebf0d8 r11 0x5dce77652bbe41d4 r12 0xffffffff829e6990 cpu_info_full_primary+0x2990 r13 0 r14 0 r15 0x1 rip 0xffffffff81d11d58 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000211f57c0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=311060 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000211e97a0,0xffff8000211e8d30 process=0xffff8000ffffe568 user=0xffff8000211f0000, vmspace=0xffffffff82bb5ec0 estcpu=0, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 58653 142241 21013 32767 2 0x10 syz-executor.5 58653 428328 21013 32767 2 0x4000010 syz-executor.5 30050 478223 42135 32767 2 0x10 syz-executor.6 30050 239913 42135 32767 2 0x4000010 syz-executor.6 30050 498820 42135 32767 3 0x4000090 fsleep syz-executor.6 50875 225991 36376 32767 2 0x490 syz-executor.2 50875 320494 36376 32767 3 0x4000090 fsleep syz-executor.2 50875 422845 36376 32767 3 0x4000090 ttyin syz-executor.2 50875 115102 36376 32767 3 0x4000090 fsleep syz-executor.2 2417 12371 87981 32767 2 0x490 syz-executor.4 2417 444640 87981 32767 3 0x4000090 netio syz-executor.4 2417 433800 87981 32767 3 0x4000090 fsleep syz-executor.4 2417 382788 87981 32767 3 0x4000090 fsleep syz-executor.4 42135 191257 15728 32767 2 0x490 syz-executor.6 15728 157354 72661 0 3 0x82 wait syz-executor.6 28938 177653 0 0 3 0x14200 bored sosplice 28402 79572 55102 32767 2 0x10 syz-executor.1 62903 263039 5856 32767 2 0x490 syz-executor.3 74742 465263 32004 32767 2 0x10 syz-executor.7 32004 318554 72661 0 3 0x82 wait syz-executor.7 36376 437091 86389 32767 2 0x490 syz-executor.2 21013 203702 38513 32767 2 0x10 syz-executor.5 55102 299873 72661 0 3 0x82 wait syz-executor.1 38513 199687 72661 0 3 0x82 wait syz-executor.5 5856 383915 72661 0 3 0x82 wait syz-executor.3 87981 262587 24922 32767 7 0x10 syz-executor.4 86389 28617 72661 0 3 0x82 wait syz-executor.2 24922 435110 72661 0 3 0x82 wait syz-executor.4 93764 96934 72661 0 3 0x82 wait syz-executor.0 72661 173163 1687 0 3 0x82 wait syz-fuzzer 72661 114823 1687 0 2 0x4000482 syz-fuzzer 72661 441620 1687 0 3 0x4000082 wait syz-fuzzer 72661 269361 1687 0 3 0x4000082 wait syz-fuzzer 72661 351442 1687 0 3 0x4000082 thrsleep syz-fuzzer 72661 74518 1687 0 3 0x4000082 wait syz-fuzzer 72661 646 1687 0 3 0x4000082 thrsleep syz-fuzzer 72661 521451 1687 0 3 0x4000082 wait syz-fuzzer 72661 53565 1687 0 3 0x4000082 thrsleep syz-fuzzer 72661 184645 1687 0 3 0x4000082 wait syz-fuzzer 72661 8480 1687 0 3 0x4000082 wait syz-fuzzer 72661 237712 1687 0 3 0x4000082 thrsleep syz-fuzzer 72661 54635 1687 0 3 0x4000082 thrsleep syz-fuzzer 72661 325756 1687 0 3 0x4000082 thrsleep syz-fuzzer 72661 38033 1687 0 3 0x4000082 kqread syz-fuzzer 72661 296245 1687 0 3 0x4000082 wait syz-fuzzer 1687 494272 57395 0 3 0x10008a sigsusp ksh 57395 399675 96477 0 3 0x9a kqread sshd 10526 300759 1 0 3 0x100083 ttyin getty 96477 460816 1 0 3 0x88 kqread sshd 24459 386187 93648 73 3 0x1100090 kqread syslogd 93648 310904 1 0 3 0x100082 netio syslogd 74576 212373 1 0 3 0x100080 kqread resolvd 19237 522437 12584 77 3 0x100092 kqread dhcpleased 43773 503003 12584 77 3 0x100092 kqread dhcpleased 12584 90469 1 0 3 0x80 kqread dhcpleased 1159 259850 0 0 2 0x14200 smr 84619 354293 0 0 2 0x14200 zerothread 72421 128384 0 0 3 0x14200 aiodoned aiodoned 45987 523771 0 0 3 0x14200 syncer update 68663 209362 0 0 3 0x14200 cleaner cleaner 81066 66454 0 0 3 0x14200 reaper reaper 39377 43936 0 0 3 0x14200 pgdaemon pagedaemon 87807 453215 0 0 3 0x14200 bored viomb 67504 309908 0 0 3 0x40014200 acpi0 acpi0 91255 513229 0 0 3 0x40014200 idle1 97869 333008 0 0 3 0x14200 bored softnet 45901 363910 0 0 3 0x14200 bored softnet 52575 523816 0 0 3 0x14200 bored softnet 6979 378369 0 0 3 0x14200 bored softnet 94144 312648 0 0 3 0x14200 bored systqmp 18166 56213 0 0 3 0x14200 bored systq *33335 311060 0 0 7 0x40014200 softclock 52552 427180 0 0 3 0x40014200 idle0 1 292045 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 33335 (softclock) thread 0xffff8000211e9500 (311060) exclusive rwlock netlock r = 0 (0xffffffff829640b0) #0 witness_lock+0x44d #1 arptimer+0x22 sys/netinet/if_ether.c:132 #2 timeout_run+0xcc sys/kern/kern_timeout.c:641 #3 softclock_thread+0x134 sys/kern/kern_timeout.c:765 #4 proc_trampoline+0x1c shared rwlock timeout r = 0 (0xffffffff829e0fe0) #0 witness_lock+0x44d #1 timeout_run+0xb7 sys/kern/kern_timeout.c:637 #2 softclock_thread+0x134 sys/kern/kern_timeout.c:765 #3 proc_trampoline+0x1c exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82b664c0) #0 witness_lock+0x44d #1 __mp_acquire_count+0x48 sys/kern/kern_lock.c:227 #2 mi_switch+0x3bb sys/kern/sched_bsd.c:415 #3 sleep_finish+0x180 sys/kern/kern_synch.c:417 #4 softclock_thread+0xd9 sys/kern/kern_timeout.c:760 #5 proc_trampoline+0x1c ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10220 6413K 6420K 78643K 11318 0 pcb 13 10K 12K 78643K 15 0 rtable 242 6K 7K 78643K 751 0 ifaddr 82 16K 16K 78643K 98 0 sysctl 3 1K 3K 78643K 11 0 counters 60 35K 35K 78643K 64 0 ioctlops 0 0K 2K 78643K 153 0 iov 0 0K 16K 78643K 493 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1272 80K 80K 78643K 1835 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 17K 78643K 1289 0 VM map 2 1K 1K 78643K 2 0 sem 12 1K 1K 78643K 2497 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 22 81K 129K 78643K 5587 0 sigio 0 0K 0K 78643K 254 0 proc 56 78K 103K 78643K 1165 0 subproc 104 6K 6K 78643K 130 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 273 0 in_multi 99 6K 6K 78643K 144 0 ether_multi 1 0K 0K 78643K 8 0 mrt 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 229 1023K 1023K 78643K 229 0 exec 0 0K 1K 78643K 701 0 tdb 3 0K 0K 78643K 3 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 8 62K 64K 78643K 10 0 UVM amap 311 88K 984K 78643K 39102 0 UVM aobj 131 4K 4K 78643K 131 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 119 0 NDP 11 0K 2K 78643K 33 0 temp 124 4702K 4782K 78643K 15926 0 kqueue 12 18K 24K 78643K 279 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 22 0 0 1 0 1 1 0 8 0 rtpcb 120 2601 0 2598 11 8 3 5 0 8 2 rtentry 112 141 0 27 4 0 4 4 0 8 0 unpcb 144 10201 0 10187 42 36 6 11 0 8 5 syncache 296 35 0 35 8 7 1 1 0 8 1 tcpqe 32 212 0 212 6 6 0 1 0 8 0 tcpcb 776 2081 0 2077 50 47 3 8 0 8 2 arp 120 23 0 4 1 0 1 1 0 8 0 ipq 40 3 0 3 1 1 0 1 0 8 0 ipqe 40 9 0 9 1 1 0 1 0 8 0 inpcb 368 4456 0 4449 56 51 5 15 0 8 4 nd6 48 37 0 10 1 0 1 1 0 8 0 kcovpl 48 10 0 2 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 582 0 117 32 2 30 30 0 8 0 art_table 32 583 0 117 4 0 4 4 0 8 0 art_node 16 140 0 36 1 0 1 1 0 8 0 sysvmsgpl 40 80 0 75 1 0 1 1 0 8 0 semapl 112 2495 0 2485 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 8424 0 6968 92 0 92 92 0 8 0 ffsino 272 8424 0 6968 98 0 98 98 0 8 0 nchpl 144 15274 0 13639 63 1 62 63 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 55154 0 55154 5 4 1 2 0 8 1 percpumem 16 44 0 2 1 0 1 1 0 8 0 kstatmem 264 26 0 4 2 0 2 2 0 8 0 scxspl 216 60297 0 60297 23 19 4 8 0 8 4 plimitpl 152 831 0 806 7 6 1 2 0 8 0 sigapl 424 5864 0 5812 7 0 7 7 0 8 0 futexpl 64 64542 0 64537 6 5 1 1 0 8 0 knotepl 120 247 0 0 7 1 6 7 0 8 0 kqueuepl 216 941 0 933 18 15 3 5 0 8 2 pipepl 320 1801 0 1773 41 35 6 11 0 8 3 fdescpl 496 5846 0 5813 7 2 5 6 0 8 0 filepl 152 40441 0 40201 68 52 16 25 0 8 6 lockfpl 104 430 0 428 1 0 1 1 0 8 0 lockfspl 48 122 0 120 1 0 1 1 0 8 0 sessionpl 144 25 0 9 1 0 1 1 0 8 0 pgrppl 48 134 0 118 1 0 1 1 0 8 0 ucredpl 104 3711 0 3693 1 0 1 1 0 8 0 zombiepl 144 5814 0 5812 1 0 1 1 0 8 0 processpl 1064 5864 0 5812 5 1 4 5 0 8 0 procpl 672 15709 0 15633 12 4 8 8 0 8 1 sosppl 168 39 0 39 5 4 1 1 0 8 1 sockpl 488 17300 0 17276 321 310 11 53 0 8 7 mcl64k 65536 17 0 0 3 0 3 3 0 8 0 mcl16k 16384 17 0 0 3 0 3 3 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 8 0 0 1 0 1 1 0 8 0 mcl8k 8192 25 0 0 3 0 3 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 4 0 0 1 0 1 1 0 8 0 mcl2k 2048 347 0 0 43 3 40 43 0 8 0 mtagpl 96 1 0 0 1 0 1 1 0 8 0 mbufpl 256 8947 0 0 549 0 549 549 0 8 0 bufpl 288 13900 0 7564 453 0 453 453 0 8 0 anonpl 24 1176557 0 1162676 156 49 107 114 0 186 9 amapchunkpl 152 339612 0 338886 4450 4266 184 4421 0 158 153 amappl16 200 12839 0 12419 67 44 23 34 0 8 0 amappl15 192 5 0 5 1 1 0 1 0 8 0 amappl14 184 137 0 126 1 0 1 1 0 8 0 amappl13 176 14 0 14 6 5 1 1 0 8 1 amappl12 168 421 0 417 1 0 1 1 0 8 0 amappl11 160 46 0 35 1 0 1 1 0 8 0 amappl10 152 44 0 33 1 0 1 1 0 8 0 amappl9 144 1022 0 1021 1 0 1 1 0 8 0 amappl8 136 296 0 209 4 0 4 4 0 8 0 amappl7 128 94 0 78 1 0 1 1 0 8 0 amappl6 120 323 0 308 2 1 1 2 0 8 0 amappl5 112 194 0 184 1 0 1 1 0 8 0 amappl4 104 1194 0 1168 3 2 1 3 0 8 0 amappl3 96 16997 0 16941 2 0 2 2 0 8 0 amappl2 88 7433 0 7363 3 1 2 3 0 8 0 amappl1 80 132406 0 131665 25 7 18 21 0 8 1 amappl 88 38641 0 38444 7 1 6 6 0 92 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 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 18 0 17 1 0 1 1 0 8 0 aobjpl 72 130 0 0 3 0 3 3 0 8 0 uaddrrnd 24 5846 0 5813 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 5846 0 5813 1 0 1 1 0 8 0 vmmpekpl 168 49689 0 49627 3 0 3 3 0 8 0 vmmpepl 168 538377 0 535677 177 43 134 137 0 357 9 vmsppl 368 5845 0 5813 5 1 4 5 0 8 0 rwobjpl 56 148240 0 140636 112 2 110 111 0 8 0 pdppl 4096 11699 0 11626 184 103 81 97 0 8 8 pvpl 32 2307005 0 2287195 391 176 215 271 0 265 41 pmappl 248 5845 0 5813 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1536 0 166 40 0 40 40 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff825a8806) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff82622986,ffffffff8266806e,308,ffffffff8257a351) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd807ab11018) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff829f9478) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff829f9478) at timeout_run+0xcc sys/kern/kern_timeout.c:641 softclock_thread(ffff8000211e9500) at softclock_thread+0x134 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020dd8ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff82b662b8) at __mp_lock+0x12e __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82b662b8) at __mp_lock+0x12e sys/kern/kern_lock.c:147 syscall(ffff8000247a1bd0) at syscall+0x424 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff8000247a1bd0) at syscall+0x424 sys/arch/amd64/amd64/trap.c:599 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff95b0, count: 9 ddb{1}> trace x86_ipi_db(ffff800020dd8ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff82b662b8) at __mp_lock+0x12e __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82b662b8) at __mp_lock+0x12e sys/kern/kern_lock.c:147 syscall(ffff8000247a1bd0) at syscall+0x424 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff8000247a1bd0) at syscall+0x424 sys/arch/amd64/amd64/trap.c:599 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff95b0, count: -6