syzbot

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BUG: KCSAN: data-race in __vfs_write / file_remove_privs

write to 0xffff88811e7f907c of 4 bytes by task 17675 on cpu 1:
 inode_has_no_xattr include/linux/fs.h:3573 [inline]
 file_remove_privs+0x2e0/0x370 fs/inode.c:1943
 __generic_file_write_iter+0xda/0x330 mm/filemap.c:3374
 generic_file_write_iter+0x2f3/0x3e0 mm/filemap.c:3460
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write fs/read_write.c:484 [inline]
 __vfs_write+0x2d8/0x340 fs/read_write.c:497
 vfs_write+0x19b/0x350 fs/read_write.c:559
 ksys_pwrite64 fs/read_write.c:666 [inline]
 __do_sys_pwrite64 fs/read_write.c:676 [inline]
 __se_sys_pwrite64 fs/read_write.c:673 [inline]
 __x64_sys_pwrite64+0xf5/0x150 fs/read_write.c:673
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811e7f907c of 4 bytes by task 17655 on cpu 0:
 iocb_flags include/linux/fs.h:3432 [inline]
 init_sync_kiocb include/linux/fs.h:2080 [inline]
 new_sync_write fs/read_write.c:480 [inline]
 __vfs_write+0x153/0x340 fs/read_write.c:497
 vfs_write+0x19b/0x350 fs/read_write.c:559
 ksys_pwrite64 fs/read_write.c:666 [inline]
 __do_sys_pwrite64 fs/read_write.c:676 [inline]
 __se_sys_pwrite64 fs/read_write.c:673 [inline]
 __x64_sys_pwrite64+0xf5/0x150 fs/read_write.c:673
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17655 Comm: syz-executor.3 Not tainted 5.8.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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