syzbot

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BUG: KCSAN: data-race in mmap_region / task_mem

read to 0xffff8880aa33e0d8 of 8 bytes by task 19698 on cpu 0:
 task_mem+0x323/0x450 fs/proc/task_mmu.c:68
 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
 do_loop_readv_writev fs/read_write.c:714 [inline]
 do_loop_readv_writev fs/read_write.c:701 [inline]
 do_iter_read+0x357/0x3d0 fs/read_write.c:935
 vfs_readv+0x9c/0xf0 fs/read_write.c:997
 do_preadv+0x131/0x1d0 fs/read_write.c:1089
 __do_sys_preadv fs/read_write.c:1139 [inline]
 __se_sys_preadv fs/read_write.c:1134 [inline]
 __x64_sys_preadv+0x61/0x80 fs/read_write.c:1134
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880aa33e0d8 of 8 bytes by task 19695 on cpu 1:
 vm_stat_account mm/mmap.c:3310 [inline]
 mmap_region+0x93a/0xd50 mm/mmap.c:1819
 do_mmap+0x6c8/0xba0 mm/mmap.c:1555
 do_mmap_pgoff include/linux/mm.h:2338 [inline]
 vm_mmap_pgoff+0x12d/0x190 mm/util.c:506
 ksys_mmap_pgoff+0x99/0x420 mm/mmap.c:1607
 __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/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19695 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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