The patch titled
Subject: decompress_bunzip2: fix rare decompression failure
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
decompress_bunzip2-fix-rare-decompression-failure.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/decompress_bunzip2-fix-rare-decompression-failure.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
Subject: decompress_bunzip2: fix rare decompression failure
Date: Wed, 17 Jul 2024 17:20:16 +0100
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>
---
lib/decompress_bunzip2.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/lib/decompress_bunzip2.c~decompress_bunzip2-fix-rare-decompression-failure
+++ a/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
_
Patches currently in -mm which might be from ross.lagerwall@xxxxxxxxxx are
decompress_bunzip2-fix-rare-decompression-failure.patch
