syzbot

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BUG: KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one

write to 0xffff8880a7afe500 of 8 bytes by task 18773 on cpu 1:
 munlock_vma_pages_range+0x59/0x790 mm/mlock.c:448
 munlock_vma_pages_all mm/internal.h:306 [inline]
 exit_mmap+0x24f/0x300 mm/mmap.c:3124
 __mmput kernel/fork.c:1082 [inline]
 mmput+0xea/0x280 kernel/fork.c:1103
 exit_mm kernel/exit.c:485 [inline]
 do_exit+0x4ac/0x18c0 kernel/exit.c:784
 do_group_exit+0xb4/0x1c0 kernel/exit.c:895
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x2f/0x6c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880a7afe500 of 8 bytes by task 18724 on cpu 0:
 try_to_unmap_one+0x105/0x16f0 mm/rmap.c:1382
 rmap_walk_file+0x23c/0x590 mm/rmap.c:1920
 rmap_walk+0x118/0x190 mm/rmap.c:1938
 try_to_munlock+0x8b/0xb0 mm/rmap.c:1789
 __munlock_isolated_page+0x89/0x1a0 mm/mlock.c:138
 __munlock_pagevec+0x392/0x7a0 mm/mlock.c:346
 munlock_vma_pages_range+0x5cc/0x790 mm/mlock.c:499
 munlock_vma_pages_all mm/internal.h:306 [inline]
 exit_mmap+0x24f/0x300 mm/mmap.c:3124
 __mmput kernel/fork.c:1082 [inline]
 mmput+0xea/0x280 kernel/fork.c:1103
 exit_mm kernel/exit.c:485 [inline]
 do_exit+0x4ac/0x18c0 kernel/exit.c:784
 do_group_exit+0xb4/0x1c0 kernel/exit.c:895
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x2f/0x6c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18724 Comm: syz-executor.5 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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