linux-kernel - [PATCH] decompress_bunzip2: Fix rare decompression failure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20240717162016.1514077-1-ross.lagerwall@citrix.com>
Date: Wed, 17 Jul 2024 17:20:16 +0100
From: Ross Lagerwall <ross.lagerwall@...rix.com>
To: linux-kernel@...r.kernel.org
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	Alain Knaff <alain@...ff.lu>,
	"H. Peter Anvin" <hpa@...or.com>,
	Ross Lagerwall <ross.lagerwall@...rix.com>
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.

Fixes: bc22c17e12c1 ("bzip2/lzma: library support for gzip, bzip2 and lzma decompression")
Signed-off-by: Ross Lagerwall <ross.lagerwall@...rix.com>
---
 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 3518e7394eca..ca736166f100 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
-- 
2.45.2