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BUG: KMSAN: uninit-value in rcu_cblist_dequeue+0x1fd/0x290 kernel/rcu/rcu_segcblist.c:55
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.16.0+ #87
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:683
 rcu_cblist_dequeue+0x1fd/0x290 kernel/rcu/rcu_segcblist.c:55
 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: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:ffff8801d96bfdf0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff12
RAX: ffff8801fddd81a0 RBX: 0000000000000000 RCX: ffff880000000000
RDX: ffff8801fd9d81a0 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff8801d96bfe28 R08: 0000000001080020 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000100000 R12: 0000000000000000
R13: ffff8801d9633b00 R14: ffff8801d96bfe8c R15: ffff8801d9634418
 arch_cpu_idle+0x20/0x30 arch/x86/kernel/process.c:345
 default_idle_call kernel/sched/idle.c:98 [inline]
 cpuidle_idle_call kernel/sched/idle.c:156 [inline]
 do_idle+0x349/0x790 kernel/sched/idle.c:246
 cpu_startup_entry+0x45/0x50 kernel/sched/idle.c:351
 start_secondary+0x39d/0x470 arch/x86/kernel/smpboot.c:267
 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239

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:3060
 call_rcu_sched+0x32/0x40 kernel/rcu/tree.c:3100
 free_pid+0x441/0x450 kernel/pid.c:156
 __change_pid kernel/pid.c:294 [inline]
 detach_pid+0x35a/0x370 kernel/pid.c:299
 __unhash_process kernel/exit.c:75 [inline]
 __exit_signal kernel/exit.c:156 [inline]
 release_task+0x10a0/0x2530 kernel/exit.c:200
 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: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
Local variable description: ----tlb.i@ldt_arch_exit_mmap
Variable was created at:
 ldt_arch_exit_mmap+0x46/0x160 arch/x86/kernel/ldt.c:298
 arch_exit_mmap arch/x86/include/asm/mmu_context.h:244 [inline]
 exit_mmap+0x30f/0x950 mm/mmap.c:3009
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