Source:
https://bugzilla.redhat.com/show_bug.cgi?id=1174851
Info:
http://www.ocert.org/advisories/ocert-2014-011.html

--- a/extract.c	2009-03-14 02:32:52.000000000 +0100
+++ b/extract.c	2014-12-05 22:43:13.000000000 +0100
@@ -2221,10 +2234,17 @@ static int test_compr_eb(__G__ eb, eb_si
     if (compr_offset < 4)                /* field is not compressed: */
         return PK_OK;                    /* do nothing and signal OK */
 
+    /* Return no/bad-data error status if any problem is found:
+     *    1. eb_size is too small to hold the uncompressed size
+     *       (eb_ucsize).  (Else extract eb_ucsize.)
+     *    2. eb_ucsize is zero (invalid).  2014-12-04 SMS.
+     *    3. eb_ucsize is positive, but eb_size is too small to hold
+     *       the compressed data header.
+     */
     if ((eb_size < (EB_UCSIZE_P + 4)) ||
-        ((eb_ucsize = makelong(eb+(EB_HEADSIZE+EB_UCSIZE_P))) > 0L &&
-         eb_size <= (compr_offset + EB_CMPRHEADLEN)))
-        return IZ_EF_TRUNC;               /* no compressed data! */
+     ((eb_ucsize = makelong( eb+ (EB_HEADSIZE+ EB_UCSIZE_P))) == 0L) ||
+     ((eb_ucsize > 0L) && (eb_size <= (compr_offset + EB_CMPRHEADLEN))))
+        return IZ_EF_TRUNC;             /* no/bad compressed data! */
 
     if (
 #ifdef INT_16BIT