[sureglymop]

So you're telling me my size 0 file may unknowingly be a large key/value db? Neat.

The system call to read these attributes is getxattr(), for anyone curious.

[alance]

Ha, it suddenly sounds like trouble.

Eg: one could piggy-back an entirely new file onto an existing file (it might have to be text encoded?).

It looks like the kernel might impose a limit of 64KiB on a file's metadata, but that's still quite a lot of room for data smuggling...