==================================================================
BUG: KMSAN: uninit-value in rcu_cblist_dequeue+0x1bb/0x290 kernel/rcu/rcu_segcblist.c:54
CPU: 1 PID: 3564 Comm: sshd Not tainted 4.16.0+ #82
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
 rcu_cblist_dequeue+0x1bb/0x290 kernel/rcu/rcu_segcblist.c:54
 rcu_do_batch kernel/rcu/tree.c:2672 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2933 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2900 [inline]
 rcu_process_callbacks+0x17cf/0x2070 kernel/rcu/tree.c:2917
 __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:541
 smp_apic_timer_interrupt+0x64/0x90 arch/x86/kernel/apic/apic.c:1055
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:857
 </IRQ>
RIP: 0010:do_syscall_64+0x6b/0x430 arch/x86/entry/common.c:277
RSP: 0018:ffff8801ad11fea0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff12
RAX: 0000000000000000 RBX: 00000000100801c1 RCX: ffff880000000000
RDX: ffff8801cc58ffd0 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff8801ad11ff48 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000000e
R13: ffff8801aa6de198 R14: ffff8801ad11ffd0 R15: ffff8801aa6dd880
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x7fbb30e963e0
RSP: 002b:00007ffeb4739038 EFLAGS: 00000246 ORIG_RAX: 000000000000000e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbb30e963e0
RDX: 0000000000000000 RSI: 00007ffeb4739050 RDI: 0000000000000002
RBP: 00005564d6c12c88 R08: 00007ffeb4739110 R09: 0101010101010101
R10: 0000000000000008 R11: 0000000000000246 R12: 00005564d81e0b60
R13: 00005564d6c10fb4 R14: 0000000000000028 R15: 00005564d6c12ca0

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:521
 rcu_cblist_dequeue+0x1e0/0x290 kernel/rcu/rcu_segcblist.c:54
 rcu_do_batch kernel/rcu/tree.c:2671 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2933 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2900 [inline]
 rcu_process_callbacks+0x15cd/0x2070 kernel/rcu/tree.c:2917
 __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:521
 rcu_segcblist_enqueue+0x24c/0x2d0 kernel/rcu/rcu_segcblist.c:150
 __call_rcu+0x227/0xef0 kernel/rcu/tree.c:3060
 call_rcu_sched+0x32/0x40 kernel/rcu/tree.c:3100
 file_free fs/file_table.c:55 [inline]
 __fput+0x90e/0xa10 fs/file_table.c:226
 ____fput+0x37/0x40 fs/file_table.c:243
 task_work_run+0x243/0x2c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x10e1/0x38d0 kernel/exit.c:867
 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:809
 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+0x36d/0x430 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
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:521
 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+0x1b/0x40 arch/x86/entry/entry_64.S:993
 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
 SYSC_exit_group+0x21/0x30 kernel/exit.c:981
 SyS_exit_group+0x25/0x30 kernel/exit.c:979
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Local variable description: ----key1.i@do_futex
Variable was created at:
 do_futex+0x341/0x6ad0 kernel/futex.c:3499
 SYSC_futex+0x3e1/0x810 kernel/futex.c:3587