==================================================================
BUG: KASAN: use-after-free in hlist_move_list include/linux/list.h:729 [inline]
BUG: KASAN: use-after-free in __collect_expired_timers kernel/time/timer.c:1339 [inline]
BUG: KASAN: use-after-free in collect_expired_timers kernel/time/timer.c:1569 [inline]
BUG: KASAN: use-after-free in __run_timers+0xa2e/0xb90 kernel/time/timer.c:1616
Write of size 8 at addr ffff8801c365c048 by task syz-executor6/4763

CPU: 0 PID: 4763 Comm: syz-executor6 Not tainted 4.14.0-rc3+ #22
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 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+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:435
 hlist_move_list include/linux/list.h:729 [inline]
 __collect_expired_timers kernel/time/timer.c:1339 [inline]
 collect_expired_timers kernel/time/timer.c:1569 [inline]
 __run_timers+0xa2e/0xb90 kernel/time/timer.c:1616
 run_timer_softirq+0x4c/0xb0 kernel/time/timer.c:1646
 __do_softirq+0x29d/0xbb2 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:770
 </IRQ>
RIP: 0023:0x804a84b
RSP: 002b:000000000846f8e0 EFLAGS: 00000a07 ORIG_RAX: ffffffffffffff10
RAX: 0000000097bc4e01 RBX: 0000000008128000 RCX: 0000000000012f78
RDX: 00000000ba182d36 RSI: 0000000000000753 RDI: 0000000000002547
RBP: 0000000000001af2 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000216 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4003:
 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
 __do_kmalloc_node mm/slab.c:3689 [inline]
 __kmalloc_node+0x47/0x70 mm/slab.c:3696
 kmalloc_node include/linux/slab.h:535 [inline]
 kvmalloc_node+0x64/0xd0 mm/util.c:397
 kvmalloc include/linux/mm.h:529 [inline]
 kvzalloc include/linux/mm.h:537 [inline]
 alloc_netdev_mqs+0x16e/0xed0 net/core/dev.c:8023
 tun_set_iff drivers/net/tun.c:2022 [inline]
 __tun_chr_ioctl+0x12be/0x3d20 drivers/net/tun.c:2276
 tun_chr_compat_ioctl+0x29/0x30 drivers/net/tun.c:2549
 C_SYSC_ioctl fs/compat_ioctl.c:1593 [inline]
 compat_SyS_ioctl+0x1d7/0x3290 fs/compat_ioctl.c:1540
 do_syscall_32_irqs_on arch/x86/entry/common.c:329 [inline]
 do_fast_syscall_32+0x3f2/0xf05 arch/x86/entry/common.c:391
 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:124

Freed by task 4003:
 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:7975 [inline]
 free_netdev+0x2cf/0x360 net/core/dev.c:8137
 tun_set_iff drivers/net/tun.c:2105 [inline]
 __tun_chr_ioctl+0x2cf6/0x3d20 drivers/net/tun.c:2276
 tun_chr_compat_ioctl+0x29/0x30 drivers/net/tun.c:2549
 C_SYSC_ioctl fs/compat_ioctl.c:1593 [inline]
 compat_SyS_ioctl+0x1d7/0x3290 fs/compat_ioctl.c:1540
 do_syscall_32_irqs_on arch/x86/entry/common.c:329 [inline]
 do_fast_syscall_32+0x3f2/0xf05 arch/x86/entry/common.c:391
 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:124

The buggy address belongs to the object at ffff8801c3658c40
 which belongs to the cache kmalloc-16384 of size 16384
The buggy address is located 13320 bytes inside of
 16384-byte region [ffff8801c3658c40, ffff8801c365cc40)
The buggy address belongs to the page:
page:ffffea00070d9600 count:1 mapcount:0 mapping:ffff8801c3658c40 index:0x0 compound_mapcount: 0
flags: 0x200000000008100(slab|head)
raw: 0200000000008100 ffff8801c3658c40 0000000000000000 0000000100000001
raw: ffffea0007111820 ffff8801dac01c50 ffff8801dac02200 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c365bf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801c365bf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801c365c000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8801c365c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801c365c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================