syzbot

==================================================================
BUG: KCSAN: data-race in __fput / kernfs_refresh_inode

read to 0xffff88812575c9e0 of 2 bytes by task 3989 on cpu 0:
 __fput+0x1ee/0x520 fs/file_table.c:281
 ____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:164
 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

write to 0xffff88812575c9e0 of 2 bytes by task 7936 on cpu 1:
 kernfs_refresh_inode+0x42/0x140 fs/kernfs/inode.c:172
 kernfs_iop_getattr+0x68/0x90 fs/kernfs/inode.c:191
 vfs_getattr_nosec+0x12e/0x170 fs/stat.c:81
 vfs_getattr+0x54/0x70 fs/stat.c:118
 vfs_statx_fd+0x7a/0xd0 fs/stat.c:145
 vfs_fstat include/linux/fs.h:3265 [inline]
 __do_sys_newfstat+0x49/0xa0 fs/stat.c:378
 __se_sys_newfstat fs/stat.c:375 [inline]
 __x64_sys_newfstat+0x3a/0x50 fs/stat.c:375
 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: 7936 Comm: udevd Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================