syzbot

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BUG: KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one

write to 0xffff88808eb2fc08 of 8 bytes by task 24158 on cpu 0:
 munlock_vma_pages_range+0x4f/0x790 mm/mlock.c:447
 munlock_vma_pages_all mm/internal.h:344 [inline]
 exit_mmap+0x128/0x3b0 mm/mmap.c:3167
 __mmput+0xa2/0x220 kernel/fork.c:1076
 mmput+0x38/0x40 kernel/fork.c:1097
 exit_mm+0x2c8/0x330 kernel/exit.c:483
 do_exit+0x40f/0x16c0 kernel/exit.c:793
 do_group_exit+0xcb/0x180 kernel/exit.c:903
 get_signal+0xe9f/0x1650 kernel/signal.c:2757
 arch_do_signal+0x25/0x270 arch/x86/kernel/signal.c:811
 exit_to_user_mode_loop kernel/entry/common.c:159 [inline]
 exit_to_user_mode_prepare+0x124/0x210 kernel/entry/common.c:190
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:265
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88808eb2fc08 of 8 bytes by task 24130 on cpu 1:
 try_to_unmap_one+0xac/0x1880 mm/rmap.c:1389
 rmap_walk_file+0x260/0x4f0 mm/rmap.c:1933
 rmap_walk mm/rmap.c:1951 [inline]
 try_to_munlock+0xe7/0x150 mm/rmap.c:1802
 __munlock_isolated_page mm/mlock.c:137 [inline]
 __munlock_pagevec+0x54d/0x7e0 mm/mlock.c:345
 munlock_vma_pages_range+0x591/0x790 mm/mlock.c:498
 munlock_vma_pages_all mm/internal.h:344 [inline]
 exit_mmap+0x128/0x3b0 mm/mmap.c:3167
 __mmput+0xa2/0x220 kernel/fork.c:1076
 mmput+0x38/0x40 kernel/fork.c:1097
 exit_mm+0x2c8/0x330 kernel/exit.c:483
 do_exit+0x40f/0x16c0 kernel/exit.c:793
 do_group_exit+0xcb/0x180 kernel/exit.c:903
 get_signal+0xe9f/0x1650 kernel/signal.c:2757
 arch_do_signal+0x25/0x270 arch/x86/kernel/signal.c:811
 exit_to_user_mode_loop kernel/entry/common.c:159 [inline]
 exit_to_user_mode_prepare+0x124/0x210 kernel/entry/common.c:190
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:265
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 24130 Comm: syz-executor.5 Not tainted 5.9.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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