syzbot

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BUG: KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one

write to 0xffff888132b25e90 of 8 bytes by task 28850 on cpu 0:
 munlock_vma_pages_range+0x52/0x430 mm/mlock.c:423
 munlock_vma_pages_all mm/internal.h:367 [inline]
 exit_mmap+0x128/0x400 mm/mmap.c:3192
 __mmput+0x27/0x1c0 kernel/fork.c:1096
 mmput+0x3d/0x50 kernel/fork.c:1117
 exit_mm+0x360/0x450 kernel/exit.c:502
 do_exit+0x3ff/0x1560 kernel/exit.c:813
 do_group_exit+0xce/0x1a0 kernel/exit.c:923
 get_signal+0xfc3/0x1610 kernel/signal.c:2818
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888132b25e90 of 8 bytes by task 28899 on cpu 1:
 try_to_unmap_one+0xb2/0x1320 mm/rmap.c:1409
 rmap_walk_file+0x1f9/0x300 mm/rmap.c:1936
 rmap_walk mm/rmap.c:1954 [inline]
 try_to_munlock+0x8f/0xd0 mm/rmap.c:1805
 __munlock_isolated_page mm/mlock.c:121 [inline]
 __munlock_pagevec+0x95d/0xb50 mm/mlock.c:321
 munlock_vma_pages_range+0x3d8/0x430 mm/mlock.c:474
 munlock_vma_pages_all mm/internal.h:367 [inline]
 exit_mmap+0x128/0x400 mm/mmap.c:3192
 __mmput+0x27/0x1c0 kernel/fork.c:1096
 mmput+0x3d/0x50 kernel/fork.c:1117
 exit_mm+0x360/0x450 kernel/exit.c:502
 do_exit+0x3ff/0x1560 kernel/exit.c:813
 do_group_exit+0xce/0x1a0 kernel/exit.c:923
 get_signal+0xfc3/0x1610 kernel/signal.c:2818
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 28899 Comm: syz-executor.5 Not tainted 5.13.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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