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authorNatanael Copa <ncopa@alpinelinux.org>2013-04-11 12:27:47 +0000
committerNatanael Copa <ncopa@alpinelinux.org>2013-04-11 12:37:02 +0000
commitce3adccd9865fd634d89940731b9c81c178a9b4c (patch)
treee1f624a425a04778ff4daf267f85fe56b6c25b14 /main/libxml2/CVE-2013-0338.patch
parent17f105dd292281d4e6fb5176e4a0f4d1685c6ac3 (diff)
downloadaports-ce3adccd9865fd634d89940731b9c81c178a9b4c.tar.bz2
aports-ce3adccd9865fd634d89940731b9c81c178a9b4c.tar.xz
main/libxml2: fix (CVE-2013-0338)
fixes #1662
Diffstat (limited to 'main/libxml2/CVE-2013-0338.patch')
-rw-r--r--main/libxml2/CVE-2013-0338.patch151
1 files changed, 151 insertions, 0 deletions
diff --git a/main/libxml2/CVE-2013-0338.patch b/main/libxml2/CVE-2013-0338.patch
new file mode 100644
index 0000000000..201b355620
--- /dev/null
+++ b/main/libxml2/CVE-2013-0338.patch
@@ -0,0 +1,151 @@
+From 23f05e0c33987d6605387b300c4be5da2120a7ab Mon Sep 17 00:00:00 2001
+From: Daniel Veillard <veillard@redhat.com>
+Date: Tue, 19 Feb 2013 02:21:49 +0000
+Subject: Detect excessive entities expansion upon replacement
+
+If entities expansion in the XML parser is asked for,
+it is possble to craft relatively small input document leading
+to excessive on-the-fly content generation.
+This patch accounts for those replacement and stop parsing
+after a given threshold. it can be bypassed as usual with the
+HUGE parser option.
+---
+diff --git a/include/libxml/parser.h b/include/libxml/parser.h
+index e1346e4..3f5730d 100644
+--- a/include/libxml/parser.h
++++ b/include/libxml/parser.h
+@@ -308,6 +308,8 @@ struct _xmlParserCtxt {
+
+ int nodeInfoNr; /* Depth of the parsing stack */
+ int nodeInfoMax; /* Max depth of the parsing stack */
+ xmlParserNodeInfo *nodeInfoTab; /* array of nodeInfos */
++
++ unsigned long sizeentcopy; /* volume of entity copy */
+ };
+
+ /**
+diff --git a/parser.c b/parser.c
+index 91f8c90..ddf3b5b 100644
+--- a/parser.c
++++ b/parser.c
+@@ -122,7 +122,7 @@ xmlCreateEntityParserCtxtInternal(const xmlChar *URL, const xmlChar *ID,
+ */
+ static int
+ xmlParserEntityCheck(xmlParserCtxtPtr ctxt, size_t size,
+- xmlEntityPtr ent)
++ xmlEntityPtr ent, size_t replacement)
+ {
+ size_t consumed = 0;
+
+@@ -130,7 +130,24 @@ xmlParserEntityCheck(xmlParserCtxtPtr ctxt, size_t size,
+ return (0);
+ if (ctxt->lastError.code == XML_ERR_ENTITY_LOOP)
+ return (1);
+- if (size != 0) {
++ if (replacement != 0) {
++ if (replacement < XML_MAX_TEXT_LENGTH)
++ return(0);
++
++ /*
++ * If the volume of entity copy reaches 10 times the
++ * amount of parsed data and over the large text threshold
++ * then that's very likely to be an abuse.
++ */
++ if (ctxt->input != NULL) {
++ consumed = ctxt->input->consumed +
++ (ctxt->input->cur - ctxt->input->base);
++ }
++ consumed += ctxt->sizeentities;
++
++ if (replacement < XML_PARSER_NON_LINEAR * consumed)
++ return(0);
++ } else if (size != 0) {
+ /*
+ * Do the check based on the replacement size of the entity
+ */
+@@ -176,7 +193,6 @@ xmlParserEntityCheck(xmlParserCtxtPtr ctxt, size_t size,
+ */
+ return (0);
+ }
+-
+ xmlFatalErr(ctxt, XML_ERR_ENTITY_LOOP, NULL);
+ return (1);
+ }
+@@ -2743,7 +2759,7 @@ xmlStringLenDecodeEntities(xmlParserCtxtPtr ctxt, const xmlChar *str, int len,
+ while (*current != 0) { /* non input consuming loop */
+ buffer[nbchars++] = *current++;
+ if (nbchars + XML_PARSER_BUFFER_SIZE > buffer_size) {
+- if (xmlParserEntityCheck(ctxt, nbchars, ent))
++ if (xmlParserEntityCheck(ctxt, nbchars, ent, 0))
+ goto int_error;
+ growBuffer(buffer, XML_PARSER_BUFFER_SIZE);
+ }
+@@ -2785,7 +2801,7 @@ xmlStringLenDecodeEntities(xmlParserCtxtPtr ctxt, const xmlChar *str, int len,
+ while (*current != 0) { /* non input consuming loop */
+ buffer[nbchars++] = *current++;
+ if (nbchars + XML_PARSER_BUFFER_SIZE > buffer_size) {
+- if (xmlParserEntityCheck(ctxt, nbchars, ent))
++ if (xmlParserEntityCheck(ctxt, nbchars, ent, 0))
+ goto int_error;
+ growBuffer(buffer, XML_PARSER_BUFFER_SIZE);
+ }
+@@ -7203,7 +7219,7 @@ xmlParseReference(xmlParserCtxtPtr ctxt) {
+ xmlFreeNodeList(list);
+ return;
+ }
+- if (xmlParserEntityCheck(ctxt, 0, ent)) {
++ if (xmlParserEntityCheck(ctxt, 0, ent, 0)) {
+ xmlFreeNodeList(list);
+ return;
+ }
+@@ -7361,6 +7377,13 @@ xmlParseReference(xmlParserCtxtPtr ctxt) {
+ xmlNodePtr nw = NULL, cur, firstChild = NULL;
+
+ /*
++ * We are copying here, make sure there is no abuse
++ */
++ ctxt->sizeentcopy += ent->length;
++ if (xmlParserEntityCheck(ctxt, 0, ent, ctxt->sizeentcopy))
++ return;
++
++ /*
+ * when operating on a reader, the entities definitions
+ * are always owning the entities subtree.
+ if (ctxt->parseMode == XML_PARSE_READER)
+@@ -7400,6 +7423,14 @@ xmlParseReference(xmlParserCtxtPtr ctxt) {
+ } else if ((list == NULL) || (ctxt->inputNr > 0)) {
+ xmlNodePtr nw = NULL, cur, next, last,
+ firstChild = NULL;
++
++ /*
++ * We are copying here, make sure there is no abuse
++ */
++ ctxt->sizeentcopy += ent->length;
++ if (xmlParserEntityCheck(ctxt, 0, ent, ctxt->sizeentcopy))
++ return;
++
+ /*
+ * Copy the entity child list and make it the new
+ * entity child list. The goal is to make sure any
+@@ -14767,6 +14798,7 @@ xmlCtxtReset(xmlParserCtxtPtr ctxt)
+ ctxt->catalogs = NULL;
+ ctxt->nbentities = 0;
+ ctxt->sizeentities = 0;
++ ctxt->sizeentcopy = 0;
+ xmlInitNodeInfoSeq(&ctxt->node_seq);
+
+ if (ctxt->attsDefault != NULL) {
+diff --git a/parserInternals.c b/parserInternals.c
+index 02032d5..f8a7041 100644
+--- a/parserInternals.c
++++ b/parserInternals.c
+@@ -1757,6 +1757,8 @@
+ ctxt->charset = XML_CHAR_ENCODING_UTF8;
+ ctxt->catalogs = NULL;
+ ctxt->nbentities = 0;
++ ctxt->sizeentities = 0;
++ ctxt->sizeentcopy = 0;
+ xmlInitNodeInfoSeq(&ctxt->node_seq);
+ return(0);
+ }
+--