==================================================================
BUG: KCSAN: data-race in file_remove_privs / vfs_write

read-write to 0xffff88813b7ca44c of 4 bytes by task 5768 on cpu 0:
 inode_has_no_xattr include/linux/fs.h:3395 [inline]
 file_remove_privs+0x2ce/0x370 fs/inode.c:1945
 __generic_file_write_iter+0xda/0x330 mm/filemap.c:3608
 generic_file_write_iter+0x309/0x3f0 mm/filemap.c:3694
 call_write_iter include/linux/fs.h:1887 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x617/0x690 fs/read_write.c:605
 ksys_pwrite64 fs/read_write.c:712 [inline]
 __do_sys_pwrite64 fs/read_write.c:722 [inline]
 __se_sys_pwrite64 fs/read_write.c:719 [inline]
 __x64_sys_pwrite64+0xf5/0x150 fs/read_write.c:719
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88813b7ca44c of 4 bytes by task 5721 on cpu 1:
 iocb_flags include/linux/fs.h:3250 [inline]
 init_sync_kiocb include/linux/fs.h:2052 [inline]
 new_sync_write fs/read_write.c:514 [inline]
 vfs_write+0x33d/0x690 fs/read_write.c:605
 ksys_pwrite64 fs/read_write.c:712 [inline]
 __do_sys_pwrite64 fs/read_write.c:722 [inline]
 __se_sys_pwrite64 fs/read_write.c:719 [inline]
 __x64_sys_pwrite64+0xf5/0x150 fs/read_write.c:719
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5721 Comm: syz-executor.2 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 5721 Comm: syz-executor.2 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x116/0x15d lib/dump_stack.c:118
 panic+0x1e7/0x5fa kernel/panic.c:231
 kcsan_report+0x67b/0x680 kernel/kcsan/report.c:634
 kcsan_setup_watchpoint+0x46a/0x4d0 kernel/kcsan/core.c:568
 iocb_flags include/linux/fs.h:3250 [inline]
 init_sync_kiocb include/linux/fs.h:2052 [inline]
 new_sync_write fs/read_write.c:514 [inline]
 vfs_write+0x33d/0x690 fs/read_write.c:605
 ksys_pwrite64 fs/read_write.c:712 [inline]
 __do_sys_pwrite64 fs/read_write.c:722 [inline]
 __se_sys_pwrite64 fs/read_write.c:719 [inline]
 __x64_sys_pwrite64+0xf5/0x150 fs/read_write.c:719
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4179b7
Code: 12 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 a1 18 00 00 c3 48 83 ec 08 e8 07 fa ff ff 48 89 04 24 49 89 ca b8 12 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 4d fa ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f4bb4460a20 EFLAGS: 00000293 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 000000000000efa6 RCX: 00000000004179b7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000020018340 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 4000080000000000
R13: 0000000000000003 R14: 0000000000000003 R15: 0000000020167ae0
Kernel Offset: disabled
Rebooting in 86400 seconds..