xref: /third_party/libxml2/backport-malloc-fail-Fix-memory-leak-in-xmlXIncludeLoadTxt.patch

From ec05f04d8b5a0a60515235f65ed1256644a77741 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Thu, 16 Feb 2023 12:40:02 +0100
Subject: [PATCH] malloc-fail: Fix memory leak in xmlXIncludeLoadTxt

Found with libFuzzer, see #344.

Reference:https://github.com/GNOME/libxml2/commit/ec05f04d8b5a0a60515235f65ed1256644a77741
Conflict:xinclude.c

---
 xinclude.c | 67 +++++++++++++++++++++++-------------------------------
 1 file changed, 28 insertions(+), 39 deletions(-)

diff --git a/xinclude.c b/xinclude.c
index cc22848..c0b4439 100644
--- a/xinclude.c
+++ b/xinclude.c
@@ -1791,14 +1791,15 @@ error:
 static int
 xmlXIncludeLoadTxt(xmlXIncludeCtxtPtr ctxt, const xmlChar *url, int nr) {
     xmlParserInputBufferPtr buf;
-    xmlNodePtr node;
-    xmlURIPtr uri;
-    xmlChar *URL;
+    xmlNodePtr node = NULL;
+    xmlURIPtr uri = NULL;
+    xmlChar *URL = NULL;
     int i;
+    int ret = -1;
     xmlChar *encoding = NULL;
     xmlCharEncoding enc = (xmlCharEncoding) 0;
-    xmlParserCtxtPtr pctxt;
-    xmlParserInputPtr inputStream;
+    xmlParserCtxtPtr pctxt = NULL;
+    xmlParserInputPtr inputStream = NULL;
     int len;
     const xmlChar *content;
 
@@ -1814,21 +1815,19 @@ xmlXIncludeLoadTxt(xmlXIncludeCtxtPtr ctxt, const xmlChar *url, int nr) {
     if (uri == NULL) {
 	xmlXIncludeErr(ctxt, ctxt->incTab[nr]->ref, XML_XINCLUDE_HREF_URI,
 	               "invalid value URI %s\n", url);
-	return(-1);
+	goto error;
     }
     if (uri->fragment != NULL) {
 	xmlXIncludeErr(ctxt, ctxt->incTab[nr]->ref, XML_XINCLUDE_TEXT_FRAGMENT,
 	               "fragment identifier forbidden for text: %s\n",
 		       (const xmlChar *) uri->fragment);
-	xmlFreeURI(uri);
-	return(-1);
+	goto error;
     }
     URL = xmlSaveUri(uri);
-    xmlFreeURI(uri);
     if (URL == NULL) {
 	xmlXIncludeErr(ctxt, ctxt->incTab[nr]->ref, XML_XINCLUDE_HREF_URI,
 	               "invalid value URI %s\n", url);
-	return(-1);
+	goto error;
     }
 
     /*
@@ -1839,8 +1838,7 @@ xmlXIncludeLoadTxt(xmlXIncludeCtxtPtr ctxt, const xmlChar *url, int nr) {
 	xmlXIncludeErr(ctxt, ctxt->incTab[nr]->ref,
 	               XML_XINCLUDE_TEXT_DOCUMENT,
 		       "text serialization of document not available\n", NULL);
-	xmlFree(URL);
-	return(-1);
+	goto error;
     }
 
     /*
@@ -1870,11 +1868,8 @@ xmlXIncludeLoadTxt(xmlXIncludeCtxtPtr ctxt, const xmlChar *url, int nr) {
 	    xmlXIncludeErr(ctxt, ctxt->incTab[nr]->ref,
 	                   XML_XINCLUDE_UNKNOWN_ENCODING,
 			   "encoding %s not supported\n", encoding);
-	    xmlFree(encoding);
-	    xmlFree(URL);
-	    return(-1);
+	    goto error;
 	}
-	xmlFree(encoding);
     }
 
     /*
@@ -1882,27 +1877,18 @@ xmlXIncludeLoadTxt(xmlXIncludeCtxtPtr ctxt, const xmlChar *url, int nr) {
      */
     pctxt = xmlNewParserCtxt();
     inputStream = xmlLoadExternalEntity((const char*)URL, NULL, pctxt);
-    if(inputStream == NULL) {
-	xmlFreeParserCtxt(pctxt);
-	xmlFree(URL);
-	return(-1);
-    }
+    if(inputStream == NULL)
+	goto error;
     buf = inputStream->buf;
-    if (buf == NULL) {
-	xmlFreeInputStream (inputStream);
-	xmlFreeParserCtxt(pctxt);
-	xmlFree(URL);
-	return(-1);
-    }
+    if (buf == NULL)
+	goto error;
     if (buf->encoder)
 	xmlCharEncCloseFunc(buf->encoder);
     buf->encoder = xmlGetCharEncodingHandler(enc);
     node = xmlNewText(NULL);
     if (node == NULL) {
-        xmlFreeInputStream(inputStream);
-        xmlFreeParserCtxt(pctxt);
-        xmlFree(URL);
-        return(-1);
+        xmlXIncludeErrMemory(ctxt, ctxt->incTab[nr]->ref, NULL);
+	goto error;
     }
 
     /*
@@ -1921,28 +1907,31 @@ xmlXIncludeLoadTxt(xmlXIncludeCtxtPtr ctxt, const xmlChar *url, int nr) {
         if (!IS_CHAR(cur)) {
             xmlXIncludeErr(ctxt, ctxt->incTab[nr]->ref, XML_XINCLUDE_INVALID_CHAR,
                            "%s contains invalid char\n", URL);
-            xmlFreeNode(node);
-            xmlFreeInputStream(inputStream);
-            xmlFreeParserCtxt(pctxt);
-            xmlFree(URL);
-            return(-1);
+            goto error;
         }
 
         i += l;
     }
 
     xmlNodeAddContentLen(node, content, len);
-    xmlFreeParserCtxt(pctxt);
     xmlXIncludeAddTxt(ctxt, node->content, URL);
-    xmlFreeInputStream(inputStream);
 
 loaded:
     /*
      * Add the element as the replacement copy.
      */
     ctxt->incTab[nr]->inc = node;
+    node = NULL;
+    ret = 0;
+
+error:
+    xmlFreeNode(node);
+    xmlFreeInputStream(inputStream);
+    xmlFreeParserCtxt(pctxt);
+    xmlFree(encoding);
+    xmlFreeURI(uri);
     xmlFree(URL);
-    return(0);
+    return(ret);
 }
 
 /**
-- 
2.27.0