conf: forbid negative values in virDomainParseScaledValue

It makes sense for none of the callers to have negative value as an
output and, fortunately, if anyone tried defining domain with negative
memory or any other value parsed by virDomainParseScaledValue(), the
resulting value was 0.  That means we can error out during parsing as
it won't break anything.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1155843

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 39befb0c2ee59f19c5afb370fc61593ac72f965f..a351382323840dcd2e5af41918ac476424a283dc 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -6334,28 +6334,34 @@ virDomainParseScaledValue(const char *xpath,
 {
     char *xpath_full = NULL;
     char *unit = NULL;
+    char *bytes_str = NULL;
     int ret = -1;
     unsigned long long bytes;
 
     *val = 0;
     if (virAsprintf(&xpath_full, "string(%s)", xpath) < 0)
         goto cleanup;
-    ret = virXPathULongLong(xpath_full, ctxt, &bytes);
-    if (ret < 0) {
-        if (ret == -2)
-            virReportError(VIR_ERR_XML_ERROR,
-                           _("could not parse element %s"),
-                           xpath);
-        else if (required)
+
+    bytes_str = virXPathString(xpath_full, ctxt);
+    if (!bytes_str) {
+        if (!required) {
+            ret = 0;
+        } else {
             virReportError(VIR_ERR_XML_ERROR,
                            _("missing element %s"),
                            xpath);
-        else
-            ret = 0;
+        }
         goto cleanup;
     }
     VIR_FREE(xpath_full);
 
+    if (virStrToLong_ullp(bytes_str, NULL, 10, &bytes) < 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Invalid value '%s' for element '%s'"),
+                       bytes_str, xpath);
+        goto cleanup;
+    }
+
     if (virAsprintf(&xpath_full, "string(%s/@unit)", xpath) < 0)
         goto cleanup;
     unit = virXPathString(xpath_full, ctxt);
@@ -6366,6 +6372,7 @@ virDomainParseScaledValue(const char *xpath,
     *val = bytes;
     ret = 1;
  cleanup:
+    VIR_FREE(bytes_str);
     VIR_FREE(xpath_full);
     VIR_FREE(unit);
     return ret;