panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 758 Stopped at db_enter+0x1c: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 182888 93331 0 0x1010 0x4080000 1 syz-executor.7 *196619 70340 0 0x14000 0x40000200 0K softclock db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff827a5eab) at panic+0x17b sys/kern/subr_prf.c:198 __assert(ffffffff82826ce7,ffffffff82821575,2f6,ffffffff82773025) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd8078063ef8) at arptfree+0x132 sys/netinet/if_ether.c:758 arptimer(ffffffff82c81b18) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c81b18) at timeout_run+0xd0 sys/kern/kern_timeout.c:665 softclock_thread(ffff800021168000) at softclock_thread+0x114 sys/kern/kern_timeout.c:809 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 758 ddb{0}> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff827a5eab) at panic+0x17b sys/kern/subr_prf.c:198 __assert(ffffffff82826ce7,ffffffff82821575,2f6,ffffffff82773025) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd8078063ef8) at arptfree+0x132 sys/netinet/if_ether.c:758 arptimer(ffffffff82c81b18) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c81b18) at timeout_run+0xd0 sys/kern/kern_timeout.c:665 softclock_thread(ffff800021168000) at softclock_thread+0x114 sys/kern/kern_timeout.c:809 end trace frame: 0x0, count: -7 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff8000211753d0 rbx 0xffffffff82b9eba7 cpu_info_full_primary+0x2ba7 rdx 0 rcx 0xffff800021168000 rax 0xffffffff82b9dff0 cpu_info_full_primary+0x1ff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xcbdce310521931d4 r11 0x1ab2582d2d19e15d r12 0xffffffff82b9e9a8 cpu_info_full_primary+0x29a8 r13 0 r14 0 r15 0x1 rip 0xffffffff8169aeac db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff8000211753c0 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) tid=196619 pid=70340 tcnt=1 stat=onproc flags process=14000 proc=40000200 runpri=0, usrpri=51, slppri=0, nice=20 wchan=0x0, wmesg=, ps_single=0x0 forw=0xffffffffffffffff, list=0xffff800021168550,0xffff8000211682b8 process=0xffff8000ffffe9e0 user=0xffff800021170000, vmspace=0xffffffff82c835d8 estcpu=1, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 35478 88842 99011 0 2 0 syz-executor.3 93331 257679 58354 0 2 0x3010 syz-executor.7 93331 182888 58354 0 7 0x4081010 syz-executor.7 64105 261385 76827 0 3 0x1000080 nanoslp syz-executor.1 64105 275323 76827 0 3 0x5000080 netio syz-executor.1 64105 512552 76827 0 3 0x5000080 fsleep syz-executor.1 35040 15764 35409 0 2 0 syz-executor.6 35040 246972 35409 0 3 0x4000080 netio syz-executor.6 99011 517711 39747 0 3 0x82 nanoslp syz-executor.3 10082 5863 0 0 3 0x14200 bored sosplice 89256 110259 39747 0 2 0x2 syz-executor.5 35409 90971 39747 0 3 0x82 nanoslp syz-executor.6 58354 501264 39747 0 2 0x2 syz-executor.7 12431 439398 39747 0 3 0x82 piperd syz-executor.2 76827 6 39747 0 3 0x82 nanoslp syz-executor.1 32334 85994 39747 0 2 0x2 syz-executor.4 39747 185850 75435 0 3 0x2000082 thrsleep syz-fuzzer 39747 420512 75435 0 3 0x6000082 nanoslp syz-fuzzer 39747 114473 75435 0 2 0x6000082 syz-fuzzer 39747 275346 75435 0 3 0x6000082 thrsleep syz-fuzzer 39747 284225 75435 0 3 0x6000082 thrsleep syz-fuzzer 39747 59508 75435 0 3 0x6000082 wait syz-fuzzer 39747 11788 75435 0 3 0x6000082 wait syz-fuzzer 39747 425102 75435 0 3 0x6000082 wait syz-fuzzer 39747 515358 75435 0 3 0x6000082 thrsleep syz-fuzzer 39747 106268 75435 0 3 0x6000082 wait syz-fuzzer 39747 361521 75435 0 3 0x6000082 thrsleep syz-fuzzer 39747 453664 75435 0 3 0x6000082 wait syz-fuzzer 39747 205890 75435 0 3 0x6000082 wait syz-fuzzer 39747 123213 75435 0 3 0x6000082 wait syz-fuzzer 39747 408119 75435 0 3 0x6000082 wait syz-fuzzer 39747 97367 75435 0 3 0x6000082 thrsleep syz-fuzzer 75435 207252 47682 0 3 0x10008a sigsusp ksh 47682 471014 84488 0 3 0x9a kqread sshd 78301 375494 1 0 3 0x100083 ttyopn getty 84488 371877 1 0 3 0x88 kqread sshd 5983 147090 64112 74 3 0x1100092 bpf pflogd 64112 93192 1 0 3 0x80 netio pflogd 12416 116820 46876 73 3 0x1100090 kqread syslogd 46876 506029 1 0 3 0x100082 netio syslogd 7969 446099 1 0 3 0x100080 kqread resolvd 6547 233212 55632 77 3 0x100092 kqread dhcpleased 55438 490849 55632 77 3 0x100092 kqread dhcpleased 55632 484923 1 0 3 0x80 kqread dhcpleased 12291 137063 0 0 3 0x14200 bored smr 83945 448789 0 0 2 0x14200 zerothread 1540 198119 0 0 3 0x14200 aiodoned aiodoned 93258 182198 0 0 3 0x14200 syncer update 59610 25137 0 0 3 0x14200 cleaner cleaner 55077 95603 0 0 3 0x14200 reaper reaper 87153 149516 0 0 3 0x14200 pgdaemon pagedaemon 48274 128646 0 0 3 0x14200 bored viomb 70104 334998 0 0 3 0x40014200 acpi0 acpi0 23495 288784 0 0 3 0x40014200 idle1 65290 348974 0 0 3 0x14200 bored softnet3 31776 500081 0 0 3 0x14200 bored softnet2 41425 509024 0 0 3 0x14200 bored softnet1 21059 308044 0 0 3 0x14200 bored softnet0 58196 266855 0 0 3 0x14200 bored systqmp 74426 32342 0 0 3 0x14200 bored systq 4165 399588 0 0 3 0x14200 tmoslp softclockmp *70340 196619 0 0 7 0x40014200 softclock 65026 134062 0 0 3 0x40014200 idle0 1 478790 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 70340 (softclock) thread 0xffff800021168000 (196619) exclusive rwlock netlock r = 0 (0xffffffff82ba93e0) #0 witness_lock+0x447 #1 arptimer+0x26 sys/netinet/if_ether.c:132 #2 timeout_run+0xd0 sys/kern/kern_timeout.c:665 #3 softclock_thread+0x114 sys/kern/kern_timeout.c:809 #4 proc_trampoline+0x10 shared rwlock timeout r = 0 (0xffffffff82b7e8f8) #0 witness_lock+0x447 #1 timeout_run+0xbb sys/kern/kern_timeout.c:661 #2 softclock_thread+0x114 sys/kern/kern_timeout.c:809 #3 proc_trampoline+0x10 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82c65260) #0 witness_lock+0x447 #1 __mp_acquire_count+0x48 sys/kern/kern_lock.c:227 #2 mi_switch+0x46d sys/kern/sched_bsd.c:470 #3 sleep_finish+0x19b sys/kern/kern_synch.c:414 #4 msleep+0xea sys/kern/kern_synch.c:249 #5 softclock_thread+0xd0 sys/kern/kern_timeout.c:805 #6 proc_trampoline+0x10 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10224 6557K 7040K 78643K 16445 0 pcb 13 15K 17K 78643K 206 0 rtable 255 7K 8K 78643K 657 0 pf 32 9K 10K 78643K 156 0 ifaddr 45 15K 16K 78643K 112 0 ifgroup 55 2K 2K 78643K 220 0 sysctl 3 0K 0K 78643K 3 0 counters 60 35K 36K 78643K 152 0 ioctlops 0 0K 4K 78643K 1602 0 iov 0 0K 32K 78643K 506 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1410 88K 88K 78643K 3357 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 129 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 331 0 dirhash 12 2K 2K 78643K 36 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 14 49K 89K 78643K 4801 0 sigio 0 0K 0K 78643K 183 0 proc 94 93K 127K 78643K 909 0 subproc 104 6K 6K 78643K 172 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 2 0K 0K 78643K 178 0 in_multi 100 7K 7K 78643K 224 0 ether_multi 1 0K 0K 78643K 10 0 mrt 1 0K 0K 78643K 4 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 181 811K 811K 78643K 181 0 exec 0 0K 1K 78643K 1236 0 pfkey data 0 0K 0K 78643K 36 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 401 257K 258K 78643K 51137 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 135 0 NDP 12 0K 2K 78643K 84 0 temp 77 5924K 6052K 78643K 33071 0 kqueue 12 18K 30K 78643K 367 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 120 339 0 336 6 5 1 5 0 8 0 rtentry 112 183 0 64 4 0 4 4 0 8 0 unpcb 144 3715 0 3686 40 36 4 6 0 8 2 syncache 304 59 0 59 13 13 0 1 0 8 0 tcpqe 32 185 0 185 12 12 0 1 0 8 0 tcpcb 808 1682 0 1668 47 44 3 11 0 8 0 arp 120 30 0 11 1 0 1 1 0 8 0 inpcb 368 3336 0 3318 66 58 8 15 0 8 5 nd6 136 50 0 18 2 0 2 2 0 8 0 pkpcb 40 4 0 4 1 1 0 1 0 8 0 kcovpl 48 13 0 5 1 0 1 1 0 8 0 ppxss 1256 20 0 20 6 6 0 1 0 8 0 pffrag 232 5 0 5 1 1 0 1 0 482 0 pffrnode 88 5 0 5 1 1 0 1 0 8 0 pffrent 40 25 0 25 3 3 0 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 24 181 0 167 1 0 1 1 0 8 0 pfstkey 128 181 0 167 2 0 2 2 0 8 0 pfstate 376 181 0 167 6 1 5 5 0 8 0 pfrule 1344 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 256 717 0 244 32 2 30 31 0 8 0 art_table 32 718 0 244 4 0 4 4 0 8 0 art_node 16 178 0 69 1 0 1 1 0 8 0 sysvmsgpl 40 24 0 18 2 1 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 327 0 317 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 33 0 16 3 0 3 3 0 8 0 dino2pl 256 8685 0 7222 92 0 92 92 0 8 0 ffsino 272 8685 0 7222 98 0 98 98 0 8 0 nchpl 144 16133 0 15590 64 40 24 64 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 54033 0 54033 4 3 1 2 0 8 1 percpumem 16 89 0 46 1 0 1 1 0 8 0 vcpupl 2048 17 0 0 3 0 3 3 0 8 0 vmpool 696 20 0 3 2 0 2 2 0 8 0 kstatmem 264 116 0 92 2 0 2 2 0 8 0 scxspl 216 50822 0 50822 18 17 1 8 1 8 1 plimitpl 152 560 0 544 1 0 1 1 0 8 0 sigapl 424 5184 0 5137 9 3 6 8 0 8 0 futexpl 64 41103 0 41102 1 0 1 1 0 8 0 knotepl 120 744 0 0 18 1 17 18 0 8 0 kqueuepl 216 740 0 732 14 13 1 5 0 8 0 pipepl 320 874 0 847 21 18 3 8 0 8 0 fdescpl 496 5104 0 5077 5 1 4 5 0 8 0 filepl 152 33462 0 33208 65 49 16 19 0 8 6 lockfpl 104 10161 0 10159 18 16 2 6 0 8 1 lockfspl 48 1732 0 1730 1 0 1 1 0 8 0 sessionpl 144 29 0 12 1 0 1 1 0 8 0 pgrppl 48 104 0 87 1 0 1 1 0 8 0 ucredpl 104 3435 0 3420 1 0 1 1 0 8 0 zombiepl 144 5139 0 5137 2 1 1 1 0 8 0 processpl 1072 5184 0 5137 5 0 5 5 0 8 0 procpl 680 13997 0 13931 9 1 8 9 0 8 0 sosppl 168 57 0 57 5 5 0 1 0 8 0 sockpl 488 7397 0 7347 154 140 14 24 0 8 7 mcl64k 65536 19 0 0 3 0 3 3 0 8 0 mcl16k 16384 18 0 0 3 1 2 3 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 6 0 0 1 0 1 1 0 8 0 mcl8k 8192 22 0 0 3 1 2 3 0 8 0 mcl4k 4096 33 0 0 3 0 3 3 0 8 0 mcl2k2 2112 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 298 0 0 32 2 30 32 0 8 0 mtagpl 96 183 0 0 5 0 5 5 0 8 0 mbufpl 256 1216 0 0 66 0 66 66 0 8 0 bufpl 288 12988 0 6662 452 0 452 452 0 8 0 anonpl 24 557948 0 544041 93 4 89 90 0 186 0 amapchunkpl 152 156296 0 155449 55 16 39 40 0 158 2 amappl16 200 10720 0 10295 30 7 23 26 0 8 0 amappl15 192 13 0 12 1 0 1 1 0 8 0 amappl14 184 173 0 159 2 1 1 2 0 8 0 amappl13 176 82 0 82 1 1 0 1 0 8 0 amappl12 168 5890 0 5853 4 1 3 3 0 8 0 amappl11 160 66 0 51 1 0 1 1 0 8 0 amappl10 152 43 0 30 1 0 1 1 0 8 0 amappl9 144 181 0 180 2 1 1 1 0 8 0 amappl8 136 378 0 282 4 0 4 4 0 8 0 amappl7 128 223 0 200 2 0 2 2 0 8 0 amappl6 120 380 0 370 1 0 1 1 0 8 0 amappl5 112 211 0 200 1 0 1 1 0 8 0 amappl4 104 681 0 652 2 1 1 2 0 8 0 amappl3 96 30998 0 30919 5 2 3 3 0 8 0 amappl2 88 7318 0 7240 3 1 2 3 0 8 0 amappl1 80 26490 0 25940 23 10 13 23 0 8 0 amappl 88 49277 0 49046 8 1 7 7 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 5124 0 5080 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 5124 0 5080 1 0 1 1 0 8 0 vmmpekpl 168 42294 0 42231 4 0 4 4 0 8 0 vmmpepl 168 320956 0 318636 178 66 112 122 0 357 0 vmsppl 464 5123 0 5080 6 0 6 6 0 8 0 rwobjpl 56 87409 0 79800 113 4 109 109 0 8 0 pdppl 4096 10256 0 10177 273 186 87 87 0 8 8 pvpl 32 1491900 0 1472544 370 203 167 367 0 265 0 pmappl 248 5123 0 5080 3 0 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1199 0 306 27 0 27 27 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff827a5eab) at panic+0x17b sys/kern/subr_prf.c:198 __assert(ffffffff82826ce7,ffffffff82821575,2f6,ffffffff82773025) at __assert+0x29 sys/kern/subr_prf.c:157 arptfree(fffffd8078063ef8) at arptfree+0x132 sys/netinet/if_ether.c:758 arptimer(ffffffff82c81b18) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c81b18) at timeout_run+0xd0 sys/kern/kern_timeout.c:665 softclock_thread(ffff800021168000) at softclock_thread+0x114 sys/kern/kern_timeout.c:809 end trace frame: 0x0, count: -7 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1e: addq $0x8,%rsp x86_ipi_db(ffff800020d58ff0) at x86_ipi_db+0x1e 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+0x27 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc single_thread_check_locked(ffff8000212a1d48,0,0) at single_thread_check_locked+0x226 sys/kern/kern_sig.c:2033 userret(ffff8000212a1d48) at userret+0x7c single_thread_check sys/kern/kern_sig.c:2052 [inline] userret(ffff8000212a1d48) at userret+0x7c sys/kern/kern_sig.c:1968 syscall(ffff800021285b80) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff800021285b80) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xa88b9e32600, count: 7 ddb{1}> trace x86_ipi_db(ffff800020d58ff0) at x86_ipi_db+0x1e 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+0x27 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc single_thread_check_locked(ffff8000212a1d48,0,0) at single_thread_check_locked+0x226 sys/kern/kern_sig.c:2033 userret(ffff8000212a1d48) at userret+0x7c single_thread_check sys/kern/kern_sig.c:2052 [inline] userret(ffff8000212a1d48) at userret+0x7c sys/kern/kern_sig.c:1968 syscall(ffff800021285b80) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff800021285b80) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xa88b9e32600, count: -8