decompress_bunzip2: off by one in get_next_block()
authorDan Carpenter <dan.carpenter@oracle.com>
Sat, 13 Dec 2014 00:58:05 +0000 (16:58 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 13 Dec 2014 20:42:52 +0000 (12:42 -0800)
"origPtr" is used as an offset into the bd->dbuf[] array.  That array is
allocated in start_bunzip() and has "bd->dbufSize" number of elements so
the test here should be >= instead of >.

Later we check "origPtr" again before using it as an offset so I don't
know if this bug can be triggered in real life.

Fixes: bc22c17e12c1 ('bzip2/lzma: library support for gzip, bzip2 and lzma decompression')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib/decompress_bunzip2.c

index 8290e0bef7eabd9f4284b9e2558f8a4e9afab6b0..6dd0335ea61b296b5dfd77818e58e294fb2e805c 100644 (file)
@@ -184,7 +184,7 @@ static int INIT get_next_block(struct bunzip_data *bd)
        if (get_bits(bd, 1))
                return RETVAL_OBSOLETE_INPUT;
        origPtr = get_bits(bd, 24);
-       if (origPtr > dbufSize)
+       if (origPtr >= dbufSize)
                return RETVAL_DATA_ERROR;
        /* mapping table: if some byte values are never used (encoding things
           like ascii text), the compression code removes the gaps to have fewer