From 03e6da41ba5d588fe072465589a64def3dc4d82b Mon Sep 17 00:00:00 2001
From: OpenWrt community <openwrt-devel@lists.openwrt.org>
Date: Mon, 30 Oct 2023 14:44:08 +0100
Subject: [PATCH] fix: heap-based buffer overflow in the test_compr_eb
 function

https://nvd.nist.gov/vuln/detail/CVE-2014-8140

CVE: CVE-2014-8140
---
 extract.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/extract.c b/extract.c
index df0fa1c..ec31e60 100644
--- a/extract.c
+++ b/extract.c
@@ -2232,10 +2232,17 @@ static int test_compr_eb(__G__ eb, eb_size, compr_offset, test_uc_ebdata)
     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
-- 

