Blame SOURCES/libxml2-Add-missing-increments-of-recursion-depth-counter-to-XML-parser.patch

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From d88b1b5e55b9ba0962408ff5e0327bf71a79e37a Mon Sep 17 00:00:00 2001
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From: Peter Simons <psimons@suse.com>
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Date: Fri, 15 Apr 2016 11:56:55 +0200
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Subject: [PATCH] Add missing increments of recursion depth counter to XML
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 parser.
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To: libvir-list@redhat.com
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For https://bugzilla.gnome.org/show_bug.cgi?id=765207
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CVE-2016-3705
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The functions xmlParserEntityCheck() and xmlParseAttValueComplex() used to call
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xmlStringDecodeEntities() in a recursive context without incrementing the
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'depth' counter in the parser context. Because of that omission, the parser
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failed to detect attribute recursions in certain documents before running out
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of stack space.
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Signed-off-by: Daniel Veillard <veillard@redhat.com>
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---
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 parser.c | 8 ++++++++
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 1 file changed, 8 insertions(+)
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diff --git a/parser.c b/parser.c
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index 0accf54..32293d0 100644
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--- a/parser.c
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+++ b/parser.c
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@@ -144,8 +144,10 @@ xmlParserEntityCheck(xmlParserCtxtPtr ctxt, size_t size,
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 	ent->checked = 1;
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+        ++ctxt->depth;
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 	rep = xmlStringDecodeEntities(ctxt, ent->content,
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 				  XML_SUBSTITUTE_REF, 0, 0, 0);
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+        --ctxt->depth;
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 	ent->checked = (ctxt->nbentities - oldnbent + 1) * 2;
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 	if (rep != NULL) {
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@@ -3963,8 +3965,10 @@ xmlParseEntityValue(xmlParserCtxtPtr ctxt, xmlChar **orig) {
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 	 * an entity declaration, it is bypassed and left as is.
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 	 * so XML_SUBSTITUTE_REF is not set here.
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 	 */
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+        ++ctxt->depth;
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 	ret = xmlStringDecodeEntities(ctxt, buf, XML_SUBSTITUTE_PEREF,
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 				      0, 0, 0);
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+        --ctxt->depth;
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 	if (orig != NULL)
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 	    *orig = buf;
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 	else
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@@ -4089,9 +4093,11 @@ xmlParseAttValueComplex(xmlParserCtxtPtr ctxt, int *attlen, int normalize) {
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 		} else if ((ent != NULL) &&
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 		           (ctxt->replaceEntities != 0)) {
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 		    if (ent->etype != XML_INTERNAL_PREDEFINED_ENTITY) {
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+			++ctxt->depth;
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 			rep = xmlStringDecodeEntities(ctxt, ent->content,
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 						      XML_SUBSTITUTE_REF,
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 						      0, 0, 0);
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+			--ctxt->depth;
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 			if (rep != NULL) {
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 			    current = rep;
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 			    while (*current != 0) { /* non input consuming */
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@@ -4127,8 +4133,10 @@ xmlParseAttValueComplex(xmlParserCtxtPtr ctxt, int *attlen, int normalize) {
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 			(ent->content != NULL) && (ent->checked == 0)) {
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 			unsigned long oldnbent = ctxt->nbentities;
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+			++ctxt->depth;
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 			rep = xmlStringDecodeEntities(ctxt, ent->content,
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 						  XML_SUBSTITUTE_REF, 0, 0, 0);
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+			--ctxt->depth;
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 			ent->checked = (ctxt->nbentities - oldnbent + 1) * 2;
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 			if (rep != NULL) {
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-- 
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2.5.5
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