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BUG: KMSAN: uninit-value in rcu_segcblist_pend_cbs+0xa9/0xf0 kernel/rcu/rcu_segcblist.c:104
CPU: 1 PID: 3642 Comm: syz-executor2 Not tainted 4.16.0+ #84
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_segcblist_pend_cbs+0xa9/0xf0 kernel/rcu/rcu_segcblist.c:104
 rcu_accelerate_cbs+0x7e/0xca0 kernel/rcu/tree.c:1809
 rcu_report_qs_rdp kernel/rcu/tree.c:2513 [inline]
 rcu_check_quiescent_state kernel/rcu/tree.c:2552 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2884 [inline]
 rcu_process_callbacks+0x6fc/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:finish_lock_switch+0x38/0x50 kernel/sched/core.c:2632
RSP: 0018:ffff880169effbe8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff12
RAX: ffff88021f2da8c0 RBX: ffff880169ed8918 RCX: ffff880000000000
RDX: ffff88021f2db8c0 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff880169effc00 R08: 0000000001080020 R09: 0000000000000002
R10: ffffffff7fffffff R11: 0000000000100000 R12: ffff88021fd3e8c0
R13: 0000000000000001 R14: 0000000000000000 R15: ffff88021f2da8c0
 finish_task_switch+0xdb/0x230 kernel/sched/core.c:2719
 context_switch kernel/sched/core.c:2869 [inline]
 __schedule+0x68e/0x730 kernel/sched/core.c:3446
 schedule+0x1cc/0x2f0 kernel/sched/core.c:3505
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_nanosleep+0x2c3/0x9b0 kernel/time/hrtimer.c:1640
 hrtimer_nanosleep kernel/time/hrtimer.c:1694 [inline]
 SYSC_nanosleep+0x420/0x6a0 kernel/time/hrtimer.c:1726
 SyS_nanosleep+0x46/0x70 kernel/time/hrtimer.c:1713
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x480a30
RSP: 002b:0000000000a3ea98 EFLAGS: 00000246 ORIG_RAX: 0000000000000023
RAX: ffffffffffffffda RBX: 000000000000002c RCX: 0000000000480a30
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000a3eaa0
RBP: 0000000000017c66 R08: 0000000000000001 R09: 0000000001863940
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000006 R14: 000000000000019f R15: 0000000000017c36

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+0x275/0x2d0 kernel/rcu/rcu_segcblist.c:151
 __call_rcu+0x227/0xef0 kernel/rcu/tree.c:3060
 call_rcu_sched+0x32/0x40 kernel/rcu/tree.c:3100
 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: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@exit_mmap
Variable was created at:
 exit_mmap+0x48/0x950 mm/mmap.c:2992
 __mmput+0x16c/0x610 kernel/fork.c:961
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