| From bf6acd5d16057d7accbbb1bf7dc6d8c56eeb4ecc Mon Sep 17 00:00:00 2001 |
| From: Ross Lagerwall <ross.lagerwall@citrix.com> |
| Date: Wed, 17 Jul 2024 17:20:16 +0100 |
| Subject: decompress_bunzip2: fix rare decompression failure |
| |
| From: Ross Lagerwall <ross.lagerwall@citrix.com> |
| |
| 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@citrix.com |
| Fixes: bc22c17e12c1 ("bzip2/lzma: library support for gzip, bzip2 and lzma decompression") |
| Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> |
| Cc: Alain Knaff <alain@knaff.lu> |
| Cc: "H. Peter Anvin" <hpa@zytor.com> |
| Cc: <stable@vger.kernel.org> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| 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 |
