More format string warnings with possible format string vulnerability
For https://bugzilla.gnome.org/show_bug.cgi?id=761029
adds a new xmlEscapeFormatString() function to escape composed format
strings
diff --git a/xmlstring.c b/xmlstring.c
index 42e380f..cc85777 100644
--- a/xmlstring.c
+++ b/xmlstring.c
@@ -987,5 +987,60 @@
return(xmlUTF8Strndup(utf, len));
}
+/**
+ * xmlEscapeFormatString:
+ * @msg: a pointer to the string in which to escape '%' characters.
+ * Must be a heap-allocated buffer created by libxml2 that may be
+ * returned, or that may be freed and replaced.
+ *
+ * Replaces the string pointed to by 'msg' with an escaped string.
+ * Returns the same string with all '%' characters escaped.
+ */
+xmlChar *
+xmlEscapeFormatString(xmlChar **msg)
+{
+ xmlChar *msgPtr = NULL;
+ xmlChar *result = NULL;
+ xmlChar *resultPtr = NULL;
+ size_t count = 0;
+ size_t msgLen = 0;
+ size_t resultLen = 0;
+
+ if (!msg || !*msg)
+ return(NULL);
+
+ for (msgPtr = *msg; *msgPtr != '\0'; ++msgPtr) {
+ ++msgLen;
+ if (*msgPtr == '%')
+ ++count;
+ }
+
+ if (count == 0)
+ return(*msg);
+
+ resultLen = msgLen + count + 1;
+ result = (xmlChar *) xmlMallocAtomic(resultLen * sizeof(xmlChar));
+ if (result == NULL) {
+ /* Clear *msg to prevent format string vulnerabilities in
+ out-of-memory situations. */
+ xmlFree(*msg);
+ *msg = NULL;
+ xmlErrMemory(NULL, NULL);
+ return(NULL);
+ }
+
+ for (msgPtr = *msg, resultPtr = result; *msgPtr != '\0'; ++msgPtr, ++resultPtr) {
+ *resultPtr = *msgPtr;
+ if (*msgPtr == '%')
+ *(++resultPtr) = '%';
+ }
+ result[resultLen - 1] = '\0';
+
+ xmlFree(*msg);
+ *msg = result;
+
+ return *msg;
+}
+
#define bottom_xmlstring
#include "elfgcchack.h"