4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx> commit bf6acd5d16057d7accbbb1bf7dc6d8c56eeb4ecc upstream. The decompression code parses a huffman tree and counts the number of symbols for a given bit length. In rare cases, there may be >= 256 symbols with a given bit length, causing the unsigned char to overflow. This causes a decompression failure later when the code tries and fails to find the bit length for a given symbol. Since the maximum number of symbols is 258, use unsigned short instead. Link: https://lkml.kernel.org/r/20240717162016.1514077-1-ross.lagerwall@xxxxxxxxxx Fixes: bc22c17e12c1 ("bzip2/lzma: library support for gzip, bzip2 and lzma decompression") Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx> Cc: Alain Knaff <alain@xxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- lib/decompress_bunzip2.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/lib/decompress_bunzip2.c +++ b/lib/decompress_bunzip2.c @@ -232,7 +232,8 @@ static int INIT get_next_block(struct bu RUNB) */ symCount = symTotal+2; for (j = 0; j < groupCount; j++) { - unsigned char length[MAX_SYMBOLS], temp[MAX_HUFCODE_BITS+1]; + unsigned char length[MAX_SYMBOLS]; + unsigned short temp[MAX_HUFCODE_BITS+1]; int minLen, maxLen, pp; /* Read Huffman code lengths for each symbol. They're stored in a way similar to mtf; record a starting
