syzbot

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BUG: KMSAN: uninit-value in flush_tlb_func_remote+0xce/0xf0 arch/x86/mm/tlb.c:553
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.17.0-rc5+ #102
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+0x149/0x260 mm/kmsan/kmsan.c:1084
 __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:686
 flush_tlb_func_remote+0xce/0xf0 arch/x86/mm/tlb.c:553
 flush_smp_call_function_queue+0x2db/0x5f0 kernel/smp.c:243
 generic_smp_call_function_single_interrupt+0x1f/0x30 kernel/smp.c:192
 smp_call_function_single_interrupt+0x22f/0x3d0 arch/x86/kernel/smp.c:295
 call_function_single_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:885
 </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:ffff8801d8e5fdf0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff04
RAX: ffff8801fd431f38 RBX: 0000000000000000 RCX: ffff880000000000
RDX: ffff8801fd031f38 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff8801d8e5fe28 R08: 0000000001080020 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000004 R12: ffff8801d8e5fe8f
R13: ffff8801d8da57c0 R14: ffff8801d8e5fe8c R15: ffff8801d8da6098
 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+0x36d/0x830 kernel/sched/idle.c:262
 cpu_startup_entry+0x45/0x50 kernel/sched/idle.c:368
 start_secondary+0x3a2/0x470 arch/x86/kernel/smpboot.c:269
 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:279 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:294 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:685
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:529
 generic_exec_single+0x499/0x4e0 kernel/smp.c:165
 smp_call_function_single+0x28c/0x4e0 kernel/smp.c:299
 smp_call_function_many+0x662/0xdf0 kernel/smp.c:434
 native_flush_tlb_others+0x4de/0x4f0 arch/x86/mm/tlb.c:595
 flush_tlb_mm_range+0x32f/0x450 arch/x86/mm/tlb.c:644
 tlb_flush_mmu_tlbonly+0x1ce/0x5f0 mm/memory.c:246
 tlb_flush_mmu mm/memory.c:267 [inline]
 arch_tlb_finish_mmu mm/memory.c:283 [inline]
 tlb_finish_mmu+0x202/0x5c0 mm/memory.c:433
 free_ldt_pgtables arch/x86/kernel/ldt.c:216 [inline]
 ldt_arch_exit_mmap+0x130/0x160 arch/x86/kernel/ldt.c:304
 arch_exit_mmap arch/x86/include/asm/mmu_context.h:245 [inline]
 exit_mmap+0x3ef/0x970 mm/mmap.c:3094
 __mmput+0x158/0x600 kernel/fork.c:962
 mmput+0xab/0xf0 kernel/fork.c:983
 exit_mm+0x6ed/0x7a0 kernel/exit.c:545
 do_exit+0xc01/0x38d0 kernel/exit.c:854
 do_group_exit+0x1a0/0x360 kernel/exit.c:970
 get_signal+0xfcb/0x1f40 kernel/signal.c:2482
 do_signal+0xb8/0x1cf0 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+0x1af/0x230 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Local variable description: ----tlb.i@ldt_arch_exit_mmap
Variable was created at:
 ldt_arch_exit_mmap+0x46/0x160 arch/x86/kernel/ldt.c:302
 arch_exit_mmap arch/x86/include/asm/mmu_context.h:245 [inline]
 exit_mmap+0x3ef/0x970 mm/mmap.c:3094
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