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BUG: KASAN: use-after-free in tcp_orphan_retries net/ipv4/tcp_timer.c:127 [inline]
BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:362 [inline]
BUG: KASAN: use-after-free in tcp_write_timer_handler+0x90f/0x930 net/ipv4/tcp_timer.c:591
Read of size 4 at addr ffff888070f2c8e8 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.0.0-rc3+ #19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:134
 tcp_orphan_retries net/ipv4/tcp_timer.c:127 [inline]
 tcp_probe_timer net/ipv4/tcp_timer.c:362 [inline]
 tcp_write_timer_handler+0x90f/0x930 net/ipv4/tcp_timer.c:591
 tcp_write_timer+0x10e/0x1d0 net/ipv4/tcp_timer.c:607
 call_timer_fn+0x254/0x900 kernel/time/timer.c:1325
 expire_timers kernel/time/timer.c:1362 [inline]
 __run_timers+0x6fc/0xd50 kernel/time/timer.c:1681
 run_timer_softirq+0x52/0xb0 kernel/time/timer.c:1694
 __do_softirq+0x30b/0xb11 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x180/0x1d0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x1b7/0x760 arch/x86/kernel/apic/apic.c:1062
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:58
Code: ff ff ff 48 89 c7 48 89 45 d8 e8 29 6e d1 f9 48 8b 45 d8 e9 ce fe ff ff 48 89 df e8 18 6e d1 f9 eb 82 90 90 90 90 90 90 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90
RSP: 0018:ffffffff89807c60 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1325021 RBX: 1ffffffff1300f8f RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff8987e73c
RBP: ffffffff89807d20 R08: ffffffff8987dec0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff89807cf8 R14: 0000000000000000 R15: ffffffff899280f8
 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:555
 default_idle_call+0x36/0x90 kernel/sched/idle.c:93
 cpuidle_idle_call kernel/sched/idle.c:153 [inline]
 do_idle+0x386/0x5d0 kernel/sched/idle.c:262
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:353
 rest_init+0x245/0x37b init/main.c:442
 arch_call_rest_init+0xe/0x1b
 start_kernel+0x87c/0x8b7 init/main.c:740
 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470
 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

The buggy address belongs to the page:
page:ffffea0001c3cb00 count:0 mapcount:-128 mapping:0000000000000000 index:0xffff888070f2c180
flags: 0x1fffc0000000000()
raw: 01fffc0000000000 ffffea00026cc708 ffffea0001758408 0000000000000000
raw: ffff888070f2c180 0000000000000002 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888070f2c780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888070f2c800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888070f2c880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                          ^
 ffff888070f2c900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888070f2c980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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