The rustix crate's extended-attribute functions in versions >=1.0.0 and <1.1.6 incorrectly mark unwritten bytes as initialized when given a zero-length buffer, leading to undefined behavior accessible from safe Rust code. This occurs because the functions mark as initialized the number of bytes reported by the system call, even though no bytes are written when the buffer length is zero. The issue is fixed in version 1.1.6 by returning empty results for zero-length buffers and introducing new query functions to safely obtain size information.