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BUG: KASAN: use-after-free in __write_once_size include/linux/compiler.h:247 [inline]
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:632 [inline]
BUG: KASAN: use-after-free in hlist_del_rcu include/linux/rculist.h:340 [inline]
BUG: KASAN: use-after-free in nf_nat_cleanup_conntrack+0x1ca/0x1e0 net/netfilter/nf_nat_core.c:691
Write of size 8 at addr ffff8801c15da4f8 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.174+ #4
 0000000000000000 bcdf99f0c141d3e4 ffff8801db607a10 ffffffff81aad1a1
 0000000000000001 ffffea0007057680 ffff8801c15da4f8 0000000000000008
 ffffffff82361100 ffff8801db607a48 ffffffff81490120 0000000000000001
Call Trace:
 <IRQ>  [<ffffffff81aad1a1>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ>  [<ffffffff81aad1a1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff81490120>] print_address_description+0x6f/0x21b mm/kasan/report.c:252
 [<ffffffff81490358>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff81490358>] kasan_report mm/kasan/report.c:408 [inline]
 [<ffffffff81490358>] kasan_report.cold+0x8c/0x2be mm/kasan/report.c:393
 [<ffffffff81484f77>] __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:434
 [<ffffffff823612ca>] __write_once_size include/linux/compiler.h:247 [inline]
 [<ffffffff823612ca>] __hlist_del include/linux/list.h:632 [inline]
 [<ffffffff823612ca>] hlist_del_rcu include/linux/rculist.h:340 [inline]
 [<ffffffff823612ca>] nf_nat_cleanup_conntrack+0x1ca/0x1e0 net/netfilter/nf_nat_core.c:691
 [<ffffffff8232d7b0>] __nf_ct_ext_destroy+0x140/0x2a0 net/netfilter/nf_conntrack_extend.c:40
 [<ffffffff8230e217>] nf_ct_ext_destroy include/net/netfilter/nf_conntrack_extend.h:80 [inline]
 [<ffffffff8230e217>] nf_conntrack_free+0x77/0x120 net/netfilter/nf_conntrack_core.c:904
 [<ffffffff823116f0>] destroy_conntrack+0x270/0x380 net/netfilter/nf_conntrack_core.c:365
 [<ffffffff822f6cd9>] nf_conntrack_destroy+0x99/0x1a0 net/netfilter/core.c:389
 [<ffffffff821eff3a>] nf_conntrack_put include/linux/skbuff.h:3377 [inline]
 [<ffffffff821eff3a>] skb_release_head_state+0x15a/0x210 net/core/skbuff.c:649
 [<ffffffff821fd0e6>] skb_release_all+0x16/0x60 net/core/skbuff.c:659
 [<ffffffff821fd257>] __kfree_skb net/core/skbuff.c:675 [inline]
 [<ffffffff821fd257>] kfree_skb+0xf7/0x400 net/core/skbuff.c:696
 [<ffffffff823b8e9a>] inet_frag_rbtree_purge+0xaa/0xf0 net/ipv4/ip_fragment.c:761
 [<ffffffff824e152f>] inet_frag_destroy+0x21f/0x2c0 net/ipv4/inet_fragment.c:156
 [<ffffffff823b8f14>] inet_frag_put include/net/inet_frag.h:124 [inline]
 [<ffffffff823b8f14>] ipq_put+0x34/0x40 net/ipv4/ip_fragment.c:164
 [<ffffffff823b954d>] ip_expire+0x14d/0x880 net/ipv4/ip_fragment.c:265
 [<ffffffff812582dd>] call_timer_fn+0x18d/0x850 kernel/time/timer.c:1185
 [<ffffffff81258ebf>] __run_timers kernel/time/timer.c:1261 [inline]
 [<ffffffff81258ebf>] run_timer_softirq+0x51f/0xb70 kernel/time/timer.c:1444
 [<ffffffff8271bb16>] __do_softirq+0x226/0xa3f kernel/softirq.c:273
 [<ffffffff810e1a8a>] invoke_softirq kernel/softirq.c:350 [inline]
 [<ffffffff810e1a8a>] irq_exit+0x10a/0x150 kernel/softirq.c:391
 [<ffffffff8271b24e>] exiting_irq arch/x86/include/asm/apic.h:652 [inline]
 [<ffffffff8271b24e>] smp_apic_timer_interrupt+0x7e/0xb0 arch/x86/kernel/apic/apic.c:926
 [<ffffffff8271a59d>] apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:768
 <EOI>  [<ffffffff810a1dc2>] ? native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:52
 [<ffffffff81022d50>] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:423
 [<ffffffff811eb4c8>] default_idle_call+0x48/0x70 kernel/sched/idle.c:93
 [<ffffffff811ebca1>] cpuidle_idle_call kernel/sched/idle.c:157 [inline]
 [<ffffffff811ebca1>] cpu_idle_loop kernel/sched/idle.c:253 [inline]
 [<ffffffff811ebca1>] cpu_startup_entry+0x6d1/0x810 kernel/sched/idle.c:301
 [<ffffffff827055f9>] rest_init+0x190/0x199 init/main.c:410
 [<ffffffff831d58a0>] start_kernel+0x64a/0x67e init/main.c:682
 [<ffffffff831d430a>] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196
 [<ffffffff831d4443>] x86_64_start_kernel+0x137/0x15a arch/x86/kernel/head64.c:185

The buggy address belongs to the page:
page:ffffea0007057680 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c15da380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8801c15da400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8801c15da480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff8801c15da500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8801c15da580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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