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: [PATCH] decompress_bunzip2: fix rare decompression failure
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>
---
lib/decompress_bunzip2.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/decompress_bunzip2.c b/lib/decompress_bunzip2.c
index 3518e7394eca8..ca736166f1000 100644
--- a/lib/decompress_bunzip2.c
+++ b/lib/decompress_bunzip2.c
@@ -232,7 +232,8 @@ static int INIT get_next_block(struct bunzip_data *bd)
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
--
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