Lzss

How buffer overflow happens in C LZSS decompression and how to fix it

A high-severity buffer overflow vulnerability was discovered in `user/libprtos/common/lzss.c`, where the LZSS decompression routine failed to validate offset and length values decoded from compressed input before using them as indices into the `text_buf` ring buffer. An attacker supplying crafted compressed data could trigger out-of-bounds reads or writes, potentially leading to memory corruption, information disclosure, or arbitrary code execution. The fix introduces strict bounds validation on