[libvirt] [libvirt-php][PATCH 2/3] Fix some leaks related to get_string_from_xpath

[Michal Privoznik]

On 19.04.2016 16:09, Christophe Fergeau wrote:
> On Tue, Apr 19, 2016 at 03:46:41PM +0200, Michal Privoznik wrote:
>> This function not only did not free return value of
>> xmlNodeListGetString() it strdup()-ed its return value. Therefore
>> plenty of memory has been lost definitely upon return from this
>> function.
>>
>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>> ---
>>  src/libvirt-php.c | 110 ++++++++++++++++++++++++++++++------------------------
>>  1 file changed, 62 insertions(+), 48 deletions(-)
>>
>> diff --git a/src/libvirt-php.c b/src/libvirt-php.c
>> index 308e764..fb0679b 100644
>> --- a/src/libvirt-php.c
>> +++ b/src/libvirt-php.c
>> @@ -3232,19 +3232,17 @@ char *get_string_from_xpath(char *xml, char *xpath, zval **val, int *retVal)
>>      if (val != NULL) {
>>          ret = 0;
>>          for (i = 0; i < nodeset->nodeNr; i++) {
>> -            if (xmlNodeListGetString(doc, nodeset->nodeTab[i]->xmlChildrenNode, 1) != NULL) {
>> -                value = (char *)xmlNodeListGetString(doc, nodeset->nodeTab[i]->xmlChildrenNode, 1);
>> -
>> +            if ((value = xmlNodeListGetString(doc, nodeset->nodeTab[i]->xmlChildrenNode, 1))) {
>>                  snprintf(key, sizeof(key), "%d", i);
>>                  VIRT_ADD_ASSOC_STRING(*val, key, value);
>> +                free(value);
>> +                value = NULL;
> 
> 'value' is an xmlChar so must be freed with xmlFree. I'd change the
> return value of get_string_from_xpath() to make it clear that xmlFree needs to
> be used to free it as well.
> 

Yeah, I could not agree more. But problem is that would be a great
patch. Moreover, xmlFree() == free() unless some debug is turned on in
libxml2 during its compilation. And since Vasiliy will make this
function go away, I'd rather push this as is.

Michal