syzbot

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BUG: KCSAN: data-race in __fput / pid_update_inode

read to 0xffff8881252a0ac8 of 2 bytes by task 7701 on cpu 1:
 fsnotify_close include/linux/fsnotify.h:286 [inline]
 __fput+0xca/0x520 fs/file_table.c:266
 ____fput+0x1f/0x30 fs/file_table.c:313
 task_work_run+0xf6/0x130 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x353/0x370 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8881252a0ac8 of 2 bytes by task 7705 on cpu 0:
 pid_update_inode+0x51/0x70 fs/proc/base.c:1820
 pid_revalidate+0x91/0xd0 fs/proc/base.c:1841
 d_revalidate fs/namei.c:758 [inline]
 d_revalidate fs/namei.c:755 [inline]
 lookup_fast+0x618/0x700 fs/namei.c:1612
 do_last fs/namei.c:3274 [inline]
 path_openat+0x2ac/0x36e0 fs/namei.c:3525
 do_filp_open+0x11e/0x1b0 fs/namei.c:3555
 do_sys_open+0x3b3/0x4f0 fs/open.c:1097
 __do_sys_open fs/open.c:1115 [inline]
 __se_sys_open fs/open.c:1110 [inline]
 __x64_sys_open+0x55/0x70 fs/open.c:1110
 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: 0 PID: 7705 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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