LZ4_decompress_fast(9)

💖 NAME 💖

okay bestie, welcome to LZ4_decompress_fast(9) from the Kernel API Manual — this page is literally about LZ4_decompress_fast — Decompresses data from source into dest. ✨

✨ SYNOPSIS ✨

the signature is giving exactly this:

int LZ4_decompress_fast (const char *source , char *dest , int
originalSize );

🎀 ARGUMENTS 🎀

• source — source address of the compressed data 🫶
• dest — output buffer address of the uncompressed data which must be already allocated with originalSize bytes 💅
• originalSize — is the original and therefore uncompressed size 🌸

🦋 DESCRIPTION 🦋

okay so this function decompresses data from source into dest, and it fully respects memory boundaries for properly formed compressed data — no cap. it is a bit faster than LZ4_decompress_safe, which is iconic, BUT 😭 it does not provide any protection against intentionally modified data stream (malicious input). use this function in trusted environment only (data to decode comes from a trusted source). periodt. 🔥

bestie, this is the warning moment: trusted environment only — intentionally modified data stream / malicious input is not it. 🚨

🌸 RETURN 🌸

it returns the number of bytes read from the source buffer, or a negative result if decompression fails. that’s the whole return tea. 💜

🔥 SEE ALSO 🔥

kernel file ./include/linux/lz4.h, plus the whole squad:

• LZ4_compressBound(9)
• LZ4_compress_default(9)
• LZ4_compress_fast(9)
• LZ4_compress_destSize(9)
• LZ4_decompress_safe(9)
• LZ4_decompress_safe_partial(9)
• LZ4_compress_HC(9)
• LZ4_resetStreamHC(9)
• LZ4_loadDictHC(9)
• LZ4_compress_HC_continue(9)
• LZ4_saveDictHC(9)
• LZ4_resetStream(9)
• LZ4_loadDict(9)
• LZ4_saveDict(9)
• LZ4_compress_fast_continue(9)
• LZ4_setStreamDecode(9)
• LZ4_decompress_safe_continue(9)
• LZ4_decompress_fast_continue(9)
• LZ4_decompress_safe_usingDict(9)
• LZ4_decompress_fast_usingDict(9)

okay that’s the page, bestie: source ./include/linux, version/date October 2026, and this is LZ4_decompress_fast(9) — byeee 💅✨