panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 776 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 306633 27473 0 0x2 0x4000000 1 syz-fuzzer *115385 46635 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff825a8820) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff82620c5c,ffffffff8261f1db,308,ffffffff825798e6) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd80639be698) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff82aef8f0) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82aef8f0) 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/multicore/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(ffffffff825a8820) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff82620c5c,ffffffff8261f1db,308,ffffffff825798e6) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd80639be698) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff82aef8f0) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82aef8f0) 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 0xffff8000211f4ef0 rbx 0xffffffff82925b8f cpu_info_full_primary+0x2b8f rdx 0 rcx 0 rax 0xffff8000211e9500 r8 0x101010101010101 r9 0x8080808080808080 r10 0x3820f65be180d0b4 r11 0xddd621e5a11080d2 r12 0xffffffff82925990 cpu_info_full_primary+0x2990 r13 0 r14 0 r15 0x1 rip 0xffffffff8142b318 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000211f4ee0 ss 0 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=115385 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000211e97a0,0xffff8000211e9270 process=0xffff8000ffffe180 user=0xffff8000211f0000, vmspace=0xffffffff82a6d988 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 42029 48993 29094 0 2 0 syz-executor.3 42029 488241 29094 0 2 0x4000000 syz-executor.3 15126 320643 45527 0 2 0 syz-executor.1 15126 180030 45527 0 3 0x4000080 pipewr syz-executor.1 15126 262554 45527 0 3 0x4000080 kqpoll syz-executor.1 15126 226771 45527 0 3 0x4000080 kqpoll syz-executor.1 77790 33678 27473 0 2 0x2 syz-executor.7 45527 359930 27473 0 2 0x482 syz-executor.1 22298 53139 27473 0 3 0x82 piperd syz-executor.5 10358 48421 27473 0 3 0x82 nanoslp syz-executor.4 39326 176399 1 0 3 0 vmmaplk syz-executor.4 39326 413918 1 0 3 0x4000000 vmmaplk syz-executor.4 39326 43526 1 0 3 0x4000000 vmmaplk syz-executor.4 39326 477337 1 0 3 0x4000000 vmmaplk syz-executor.4 60487 113573 27473 0 2 0x2 syz-executor.6 29094 98792 27473 0 2 0x482 syz-executor.3 30985 514921 0 0 3 0x14200 bored sosplice 37892 194025 27473 0 3 0x82 piperd syz-executor.2 27473 314671 40694 0 3 0x82 wait syz-fuzzer 27473 516527 40694 0 3 0x4000082 nanoslp syz-fuzzer 27473 126973 40694 0 3 0x4000082 thrsleep syz-fuzzer 27473 363074 40694 0 3 0x4000082 thrsleep syz-fuzzer 27473 255858 40694 0 3 0x4000082 thrsleep syz-fuzzer 27473 495475 40694 0 3 0x4000082 thrsleep syz-fuzzer 27473 59288 40694 0 2 0x4000002 syz-fuzzer 27473 86909 40694 0 3 0x4000082 thrsleep syz-fuzzer 27473 492749 40694 0 3 0x4000082 wait syz-fuzzer 27473 191243 40694 0 3 0x4000082 wait syz-fuzzer 27473 248338 40694 0 3 0x4000082 wait syz-fuzzer 27473 201900 40694 0 3 0x4000082 wait syz-fuzzer 27473 250994 40694 0 3 0x4000082 wait syz-fuzzer 27473 24684 40694 0 3 0x4000082 wait syz-fuzzer 27473 306633 40694 0 7 0x4000002 syz-fuzzer 27473 183501 40694 0 3 0x4000082 wait syz-fuzzer 40694 423832 62389 0 3 0x10008a sigsusp ksh 62389 312330 62701 0 3 0x9a kqread sshd 4912 209302 1 0 3 0x100083 ttyin getty 62701 3669 1 0 3 0x88 kqread sshd 60990 44319 77456 74 3 0x1100092 bpf pflogd 77456 172877 1 0 3 0x80 netio pflogd 26652 44125 78008 73 3 0x1100090 kqread syslogd 78008 42298 1 0 3 0x100082 netio syslogd 89875 107656 1 0 3 0x100080 kqread resolvd 11012 77636 68402 77 3 0x100092 kqread dhcpleased 49126 40712 68402 77 3 0x100092 kqread dhcpleased 68402 261333 1 0 3 0x80 kqread dhcpleased 70404 434152 0 0 3 0x14200 pause smr 83330 323380 0 0 2 0x14200 zerothread 8298 401823 0 0 3 0x14200 aiodoned aiodoned 24724 231292 0 0 3 0x14200 syncer update 57353 77099 0 0 3 0x14200 cleaner cleaner 199 285351 0 0 3 0x14200 reaper reaper 32349 484932 0 0 3 0x14200 pgdaemon pagedaemon 13394 121776 0 0 3 0x14200 bored viomb 65987 328722 0 0 3 0x40014200 acpi0 acpi0 78968 437468 0 0 3 0x40014200 idle1 71875 12157 0 0 3 0x14200 bored softnet 87678 306780 0 0 3 0x14200 bored softnet 42611 75440 0 0 3 0x14200 bored softnet 77033 268466 0 0 3 0x14200 bored softnet 8512 515246 0 0 3 0x14200 bored systqmp 42170 465636 0 0 3 0x14200 bored systq *46635 115385 0 0 7 0x40014200 softclock 44028 418052 0 0 3 0x40014200 idle0 1 114775 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 39326 (syz-executor.4) thread 0xffff8000fffed500 (43526) shared rwlock vmmaplk r = 0 (0xfffffd806819f510) #0 witness_lock+0x44d #1 rw_enter+0x3e1 sys/kern/kern_rwlock.c:310 #2 vm_map_lock_ln+0xda sys/uvm/uvm_map.c:5332 #3 uvm_map_pageable+0x111 sys/uvm/uvm_map.c:2293 #4 sys_mlock+0x184 sys/uvm/uvm_mmap.c:834 #5 syscall+0x438 mi_syscall sys/sys/syscall_mi.h:101 [inline] #5 syscall+0x438 sys/arch/amd64/amd64/trap.c:599 #6 Xsyscall+0x128 Process 46635 (softclock) thread 0xffff8000211e9500 (115385) exclusive rwlock netlock r = 0 (0xffffffff8295d1b0) #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 (0xffffffff8291e078) #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 (0xffffffff82aaf200) #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 10249 6756K 7347K 78643K 23647 0 pcb 13 14K 15K 78643K 795 0 rtable 175 15K 16K 78643K 1095 0 ifaddr 73 17K 20K 78643K 394 0 counters 58 35K 37K 78643K 384 0 ioctlops 0 0K 4K 78643K 2918 0 iov 1 12K 32K 78643K 232 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1593 100K 100K 78643K 6250 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 45 0 VM map 2 1K 1K 78643K 2 0 sem 11 1K 1K 78643K 17 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 13 45K 85K 78643K 3309 0 sigio 0 0K 0K 78643K 60 0 proc 70 91K 116K 78643K 992 0 subproc 117 7K 7K 78643K 298 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 158 0 in_multi 69 4K 6K 78643K 381 0 ether_multi 1 0K 0K 78643K 43 0 mrt 1 0K 0K 78643K 15 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 205 917K 917K 78643K 205 0 exec 0 0K 1K 78643K 827 0 pfkey data 0 0K 0K 78643K 4 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 348 96K 109K 78643K 25074 0 UVM aobj 131 4K 4K 78643K 139 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 82 0 NDP 13 0K 2K 78643K 132 0 temp 139 4706K 5718K 78643K 24994 0 kqueue 12 18K 24K 78643K 291 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 120 248 0 245 4 3 1 3 0 8 0 rtentry 112 361 0 288 4 0 4 4 0 8 0 unpcb 144 2970 0 2955 32 26 6 6 0 8 5 syncache 296 23 0 23 5 5 0 1 0 8 0 tcpqe 32 351 0 351 7 7 0 1 0 8 0 tcpcb 776 944 0 935 48 46 2 8 0 8 0 arp 120 67 0 52 1 0 1 1 0 8 0 inpcb 368 3700 0 3688 61 55 6 13 0 8 3 nd6 48 73 0 58 1 0 1 1 0 8 0 pkpcb 40 12 0 12 3 3 0 1 0 8 0 kcovpl 48 22 0 13 1 0 1 1 0 8 0 mppekey 1024 4 0 4 1 0 1 1 0 8 1 ppxss 1256 113 0 113 6 5 1 1 0 8 1 pppxif 1448 19 0 19 5 5 0 1 0 8 0 pffrag 232 1 0 0 1 0 1 1 0 482 0 pffrnode 88 1 0 0 1 0 1 1 0 8 0 pffrent 40 16 0 15 4 3 1 1 0 8 0 pfosfp 40 1428 0 1005 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 123 0 104 1 0 1 1 0 8 0 pfstkey 128 123 0 104 2 1 1 2 0 8 0 pfstate 384 123 0 104 7 4 3 5 0 8 0 pfrule 1344 21 0 16 2 1 1 2 0 8 0 rttmr 136 4 0 4 1 0 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1532 0 1204 37 10 27 29 0 8 2 art_table 32 1533 0 1204 4 0 4 4 0 8 0 art_node 16 357 0 293 1 0 1 1 0 8 0 sysvmsgpl 40 2 0 2 1 1 0 1 0 8 0 semupl 112 4 0 4 1 1 0 1 0 8 0 semapl 112 9 0 0 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 dino2pl 256 5689 0 4247 91 0 91 91 0 8 0 ffsino 272 5689 0 4247 97 0 97 97 0 8 0 nchpl 144 10096 0 8460 63 0 63 63 0 8 0 rtmask 32 4 0 4 2 2 0 1 0 8 0 uvmvnodes 80 10252 0 0 210 0 210 210 0 8 0 vnodes 216 10252 0 0 570 0 570 570 0 8 0 namei 1024 40064 0 40064 4 3 1 2 0 8 1 percpumem 16 204 0 163 1 0 1 1 0 8 0 vmpool 696 8 0 8 3 3 0 1 0 8 0 kstatmem 264 164 0 138 3 0 3 3 0 8 0 scxspl 216 32678 0 32678 20 17 3 8 0 8 3 plimitpl 152 742 0 725 1 0 1 1 0 8 0 sigapl 424 3609 0 3564 9 3 6 8 0 8 0 futexpl 64 30295 0 30295 4 3 1 1 0 8 1 knotepl 120 426 0 0 11 1 10 10 0 8 0 kqueuepl 216 674 0 664 11 10 1 5 0 8 0 pipepl 320 863 0 834 25 17 8 8 0 8 5 fdescpl 496 3571 0 3545 7 2 5 5 0 8 0 filepl 152 26740 0 26484 53 37 16 19 0 8 5 lockfpl 104 1255 0 1253 5 3 2 2 0 8 1 lockfspl 48 453 0 451 1 0 1 1 0 8 0 sessionpl 144 38 0 20 1 0 1 1 0 8 0 pgrppl 48 43 0 25 1 0 1 1 0 8 0 ucredpl 104 2814 0 2801 1 0 1 1 0 8 0 zombiepl 144 3566 0 3564 3 2 1 1 0 8 0 processpl 1072 3609 0 3564 5 1 4 5 0 8 0 procpl 672 9938 0 9871 16 8 8 9 0 8 1 srpgc 96 34 0 34 9 8 1 1 0 8 1 sosppl 168 27 0 27 3 2 1 1 0 8 1 sockpl 488 6965 0 6935 159 146 13 28 0 8 8 mcl64k 65536 19 0 0 3 1 2 3 0 8 0 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 4 0 0 1 0 1 1 0 8 0 mcl8k 8192 17 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 503 0 0 62 0 62 62 0 8 0 mtagpl 96 1194 0 0 26 0 26 26 0 8 0 mbufpl 256 1441 0 0 79 0 79 79 0 8 0 bufpl 288 8939 0 2610 453 0 453 453 0 8 0 anonpl 24 743989 0 725743 170 44 126 139 0 186 3 amapchunkpl 152 70238 0 69454 57 22 35 46 0 158 0 amappl16 200 6678 0 6146 38 8 30 37 0 8 0 amappl15 192 6 0 6 1 1 0 1 0 8 0 amappl14 184 190 0 177 2 1 1 2 0 8 0 amappl13 176 12 0 11 1 0 1 1 0 8 0 amappl12 168 579 0 577 1 0 1 1 0 8 0 amappl11 160 63 0 47 1 0 1 1 0 8 0 amappl10 152 48 0 36 1 0 1 1 0 8 0 amappl9 144 960 0 960 4 4 0 1 0 8 0 amappl8 136 307 0 226 3 0 3 3 0 8 0 amappl7 128 185 0 157 2 0 2 2 0 8 0 amappl6 120 234 0 217 1 0 1 1 0 8 0 amappl5 112 220 0 211 1 0 1 1 0 8 0 amappl4 104 641 0 609 2 1 1 2 0 8 0 amappl3 96 10308 0 10254 3 1 2 2 0 8 0 amappl2 88 4074 0 3998 3 1 2 3 0 8 0 amappl1 80 83946 0 83191 26 7 19 23 0 8 1 amappl 88 24307 0 24115 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 72 138 0 8 3 0 3 3 0 8 0 uaddrrnd 24 3580 0 3554 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3580 0 3554 1 0 1 1 0 8 0 vmmpekpl 168 36063 0 35990 4 0 4 4 0 8 0 vmmpepl 168 337008 0 334345 222 79 143 164 0 357 7 vmsppl 368 3579 0 3554 5 2 3 4 0 8 0 rwobjpl 56 100093 0 87942 175 2 173 173 0 8 0 pdppl 4096 7167 0 7108 311 240 71 79 0 8 12 pvpl 32 1584640 0 1560894 397 177 220 274 0 265 9 pmappl 248 3579 0 3554 3 1 2 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1226 0 319 27 0 27 27 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(ffffffff825a8820) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff82620c5c,ffffffff8261f1db,308,ffffffff825798e6) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd80639be698) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff82aef8f0) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82aef8f0) 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