syzbot

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BUG: KASAN: slab-out-of-bounds in hlist_add_head include/linux/list.h:673 [inline]
BUG: KASAN: slab-out-of-bounds in enqueue_timer kernel/time/timer.c:520 [inline]
BUG: KASAN: slab-out-of-bounds in __internal_add_timer+0x275/0x2d0 kernel/time/timer.c:531
Write of size 8 at addr ffff88004bee3a48 by task swapper/2/0

CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.13.0-next-20170915+ #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x24e/0x340 mm/kasan/report.c:409
 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:435
 hlist_add_head include/linux/list.h:673 [inline]
 enqueue_timer kernel/time/timer.c:520 [inline]
 __internal_add_timer+0x275/0x2d0 kernel/time/timer.c:531
 internal_add_timer kernel/time/timer.c:573 [inline]
 __mod_timer kernel/time/timer.c:1024 [inline]
 mod_timer+0x622/0x15b0 kernel/time/timer.c:1071
 neigh_timer_handler+0x55b/0xca0 net/core/neighbour.c:976
 call_timer_fn+0x246/0x850 kernel/time/timer.c:1281
 expire_timers kernel/time/timer.c:1320 [inline]
 __run_timers+0x7fd/0xb90 kernel/time/timer.c:1620
 run_timer_softirq+0x4c/0xb0 kernel/time/timer.c:1646
 __do_softirq+0x2bb/0xbd0 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1d3/0x210 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:638 [inline]
 smp_apic_timer_interrupt+0x177/0x710 arch/x86/kernel/apic/apic.c:1048
 apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:577
 </IRQ>
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53
RSP: 0018:ffff88006dad7db0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
RAX: dffffc0000000000 RBX: 1ffff1000db5afb9 RCX: 0000000000000000
RDX: 1ffffffff0b59340 RSI: 0000000000000001 RDI: ffffffff85ac9a00
RBP: ffff88006dad7db0 R08: ffffffff8161bd49 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff85ac99f0
R13: ffff88006dad7e68 R14: 0000000000000000 R15: ffff88006dac6040
 arch_safe_halt arch/x86/include/asm/paravirt.h:93 [inline]
 default_idle+0xbf/0x460 arch/x86/kernel/process.c:341
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:332
 default_idle_call+0x36/0x90 kernel/sched/idle.c:98
 cpuidle_idle_call kernel/sched/idle.c:156 [inline]
 do_idle+0x256/0x3b0 kernel/sched/idle.c:246
 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:351
 start_secondary+0x2ea/0x3f0 arch/x86/kernel/smpboot.c:277
 secondary_startup_64+0xa5/0xa5 arch/x86/kernel/head_64.S:235

Allocated by task 5241:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:666 [inline]
 tipc_nametbl_init+0x241/0x5e0 net/tipc/name_table.c:810
 tipc_init_net+0x347/0x570 net/tipc/core.c:69
 ops_init+0x10a/0x570 net/core/net_namespace.c:118
 setup_net+0x319/0x720 net/core/net_namespace.c:294
 copy_net_ns+0x27c/0x580 net/core/net_namespace.c:418
 create_new_namespaces+0x425/0x880 kernel/nsproxy.c:107
 unshare_nsproxy_namespaces+0xae/0x1e0 kernel/nsproxy.c:206
 SYSC_unshare kernel/fork.c:2348 [inline]
 SyS_unshare+0x653/0xfa0 kernel/fork.c:2298
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 4155:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xca/0x250 mm/slab.c:3820
 kvfree+0x36/0x60 mm/util.c:416
 netdev_freemem net/core/dev.c:7970 [inline]
 free_netdev+0x2cf/0x360 net/core/dev.c:8132
 tun_set_iff drivers/net/tun.c:2105 [inline]
 __tun_chr_ioctl+0x2cf6/0x3d20 drivers/net/tun.c:2276
 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2521
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe

The buggy address belongs to the object at ffff88004bee0640
 which belongs to the cache kmalloc-16384 of size 16384
The buggy address is located 13320 bytes inside of
 16384-byte region [ffff88004bee0640, ffff88004bee4640)
The buggy address belongs to the page:
page:ffffea00012fb800 count:1 mapcount:0 mapping:ffff88004bee0640 index:0x0 compound_mapcount: 0
flags: 0x500000000008100(slab|head)
raw: 0500000000008100 ffff88004bee0640 0000000000000000 0000000100000001
raw: ffffea0001284620 ffffea00012e2a20 ffff88003e802200 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88004bee3900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88004bee3980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88004bee3a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                              ^
 ffff88004bee3a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88004bee3b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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