[libxml2] CVE-2015-5312 Another entity expansion issue

[Daniel Veillard <veillard src gnome org>]

commit 69030714cde66d525a8884bda01b9e8f0abf8e1e
Author: David Drysdale <drysdale google com>
Date:   Fri Nov 20 11:13:45 2015 +0800

    CVE-2015-5312 Another entity expansion issue
    
    For https://bugzilla.gnome.org/show_bug.cgi?id=756733
    It is one case where the code in place to detect entities expansions
    failed to exit when the situation was detected, leading to DoS
    Problem reported by Kostya Serebryany @ Google
    Patch provided by David Drysdale @ Google

 parser.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/parser.c b/parser.c
index b7b6668..da6e729 100644
--- a/parser.c
+++ b/parser.c
@@ -2806,6 +2806,10 @@ xmlStringLenDecodeEntities(xmlParserCtxtPtr ctxt, const xmlChar *str, int len,
                                              0, 0, 0);
                ctxt->depth--;
 
+               if ((ctxt->lastError.code == XML_ERR_ENTITY_LOOP) ||
+                   (ctxt->lastError.code == XML_ERR_INTERNAL_ERROR))
+                   goto int_error;
+
                if (rep != NULL) {
                    current = rep;
                    while (*current != 0) { /* non input consuming loop */