syzbot

==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / vfs_fsync_range

write to 0xffff8881076e2590 of 8 bytes by task 30155 on cpu 1:
 __mark_inode_dirty+0x117/0x7d0 fs/fs-writeback.c:2437
 mark_inode_dirty include/linux/fs.h:2306 [inline]
 generic_write_end+0x172/0x230 fs/buffer.c:2307
 fat_write_end+0x4e/0x160 fs/fat/inode.c:244
 generic_perform_write+0x267/0x410 mm/filemap.c:3929
 __generic_file_write_iter+0xa1/0x120 mm/filemap.c:4013
 generic_file_write_iter+0x7d/0x1c0 mm/filemap.c:4039
 do_iter_write+0x4ad/0x770 fs/read_write.c:860
 vfs_iter_write+0x56/0x70 fs/read_write.c:901
 iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
 splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff8881076e2590 of 8 bytes by task 30180 on cpu 0:
 vfs_fsync_range+0xa2/0x120 fs/sync.c:186
 generic_write_sync include/linux/fs.h:2653 [inline]
 generic_file_write_iter+0x191/0x1c0 mm/filemap.c:4043
 do_iter_write+0x4ad/0x770 fs/read_write.c:860
 vfs_iter_write+0x56/0x70 fs/read_write.c:901
 iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
 splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000000804 -> 0x0000000000000007

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 30180 Comm: syz-executor.2 Not tainted 6.7.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================