syzbot

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BUG: KCSAN: data-race in mmap_region / task_vsize

write to 0xffff88811e57f700 of 8 bytes by task 7520 on cpu 0:
 vm_stat_account mm/mmap.c:3324 [inline]
 mmap_region+0x328/0xd50 mm/mmap.c:1841
 do_mmap+0x6d4/0xba0 mm/mmap.c:1577
 do_mmap_pgoff include/linux/mm.h:2348 [inline]
 vm_mmap_pgoff+0x12d/0x190 mm/util.c:496
 ksys_mmap_pgoff+0x99/0x420 mm/mmap.c:1629
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline]
 __x64_sys_mmap+0x2e/0x40 arch/x86/kernel/sys_x86_64.c:91
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811e57f700 of 8 bytes by task 7530 on cpu 1:
 task_vsize+0x24/0x40 fs/proc/task_mmu.c:84
 do_task_stat+0xff/0x1370 fs/proc/array.c:455
 proc_tgid_stat+0x3d/0x60 fs/proc/array.c:632
 proc_single_show+0x89/0xe0 fs/proc/base.c:756
 seq_read+0x350/0x960 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/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7530 Comm: ps Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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