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BUG: KMSAN: uninit-value in rcu_cblist_dequeue+0x1bb/0x290 kernel/rcu/rcu_segcblist.c:54
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.17.0-rc3+ #88
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+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
 rcu_cblist_dequeue+0x1bb/0x290 kernel/rcu/rcu_segcblist.c:54
 rcu_do_batch kernel/rcu/tree.c:2673 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2930 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2897 [inline]
 rcu_process_callbacks+0x17f9/0x2020 kernel/rcu/tree.c:2914
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
 invoke_softirq kernel/softirq.c:365 [inline]
 irq_exit+0x202/0x240 kernel/softirq.c:405
 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:525
 smp_apic_timer_interrupt+0x64/0x90 arch/x86/kernel/apic/apic.c:1055
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
 </IRQ>
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:55 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:97 [inline]
RIP: 0010:default_idle+0x1fb/0x3c0 arch/x86/kernel/process.c:354
RSP: 0018:ffffffff8ac0fd88 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff8801fd431d78 RBX: 0000000000000000 RCX: ffff880000000000
RDX: ffff8801fd031d78 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffffffff8ac0fdc0 R08: 0000000001080020 R09: 0000000000000002
R10: 0000002254e1d6a2 R11: 0000000000000000 R12: ffffffff8ac372c0
R13: ffffffff8ac37b98 R14: ffffffff8ac0fe24 R15: ffffffff8ac37b98
 arch_cpu_idle+0x20/0x30 arch/x86/kernel/process.c:345
 default_idle_call kernel/sched/idle.c:93 [inline]
 cpuidle_idle_call kernel/sched/idle.c:153 [inline]
 do_idle+0x458/0x850 kernel/sched/idle.c:262
 cpu_startup_entry+0x45/0x50 kernel/sched/idle.c:368
 rest_init+0x1c1/0x1f0 init/main.c:442
 start_kernel+0x10fa/0x1110 init/main.c:739
 x86_64_start_reservations arch/x86/kernel/head64.c:454 [inline]
 x86_64_start_kernel+0x2fa/0x310 arch/x86/kernel/head64.c:435
 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:528
 rcu_cblist_dequeue+0x1e0/0x290 kernel/rcu/rcu_segcblist.c:54
 rcu_do_batch kernel/rcu/tree.c:2672 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2930 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2897 [inline]
 rcu_process_callbacks+0x15f4/0x2020 kernel/rcu/tree.c:2914
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:528
 rcu_segcblist_enqueue+0x24c/0x2d0 kernel/rcu/rcu_segcblist.c:150
 __call_rcu+0x227/0xef0 kernel/rcu/tree.c:3057
 call_rcu_sched+0x32/0x40 kernel/rcu/tree.c:3097
 release_task+0x24b9/0x2530 kernel/exit.c:223
 exit_notify kernel/exit.c:736 [inline]
 do_exit+0x2d91/0x38d0 kernel/exit.c:887
 do_group_exit+0x1a0/0x360 kernel/exit.c:970
 get_signal+0x1320/0x1f20 kernel/signal.c:2469
 do_signal+0xb8/0x1c80 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop arch/x86/entry/common.c:162 [inline]
 prepare_exit_to_usermode+0x271/0x3a0 arch/x86/entry/common.c:196
 syscall_return_slowpath+0xe9/0x700 arch/x86/entry/common.c:265
 do_syscall_64+0x1a6/0x220 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:528
 search_extable+0xfb/0x110 lib/extable.c:123
 search_exception_tables+0x8b/0x120 kernel/extable.c:60
 fixup_exception+0x84/0x190 arch/x86/mm/extable.c:192
 math_error+0x44d/0x600 arch/x86/kernel/traps.c:844
 do_coprocessor_error+0x29/0x30 arch/x86/kernel/traps.c:875
 coprocessor_error+0x14/0x20 arch/x86/entry/entry_64.S:999
 fpu__drop+0x27f/0x4f0 arch/x86/kernel/fpu/core.c:345
 exit_thread+0x168/0x1d0 arch/x86/kernel/process.c:128
 do_exit+0x10f0/0x38d0 kernel/exit.c:868
 do_group_exit+0x1a0/0x360 kernel/exit.c:970
 get_signal+0x1320/0x1f20 kernel/signal.c:2469
 do_signal+0xb8/0x1c80 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop arch/x86/entry/common.c:162 [inline]
 prepare_exit_to_usermode+0x271/0x3a0 arch/x86/entry/common.c:196
 syscall_return_slowpath+0xe9/0x700 arch/x86/entry/common.c:265
 do_syscall_64+0x1a6/0x220 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Local variable description: ----success.i.i.i.i.i.i.i.i.i@gup_pgd_range
Variable was created at:
 gup_pgd_range+0xe0/0x2e90 mm/gup.c:1702
 get_user_pages_fast+0x27a/0x780 mm/gup.c:1820
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