KCSAN: data-race in __do_munmap / task

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __do_munmap / task_mem (2) mm				3	1024d	1062d	0/26	auto-closed as invalid on 2021/09/03 02:16

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BUG: KCSAN: data-race in __do_munmap / task_mem

read to 0xffff88812b74c540 of 8 bytes by task 6360 on cpu 1:
 task_mem+0xd0/0x450 fs/proc/task_mmu.c:46
 proc_pid_status+0x825/0x1000 fs/proc/array.c:416
 proc_single_show+0x92/0x120 fs/proc/base.c:756
 seq_read+0x350/0x9d0 fs/seq_file.c:229
 __vfs_read+0x67/0xc0 fs/read_write.c:425
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446
 ksys_read+0xd5/0x1b0 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff88812b74c540 of 8 bytes by task 28789 on cpu 0:
 vm_stat_account mm/mmap.c:3303 [inline]
 remove_vma_list mm/mmap.c:2581 [inline]
 __do_munmap+0x7a9/0xb60 mm/mmap.c:2826
 __vm_munmap+0xb2/0x130 mm/mmap.c:2846
 __do_sys_munmap mm/mmap.c:2872 [inline]
 __se_sys_munmap mm/mmap.c:2868 [inline]
 __x64_sys_munmap+0x4c/0x60 mm/mmap.c:2868
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 28789 Comm: udevd 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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