[libvirt] [PATCH] network: fix crash when portgroup has no name

[Martin Kletzander]

On 11/28/2012 06:08 AM, Laine Stump wrote:
> This resolves: https://bugzilla.redhat.com/show_bug.cgi?id=879473
> 
> The name attribute is required for portgroup elements (yes, the RNG
> specifies that), and there is code in libvirt that assumes it is
> non-null.  Unfortunately, the portgroup parsing function wasn't
> checking for lack of portgroup. One adverse result of this was that
> attempts to update a network by adding a portgroup with no name would
> cause libvirtd to segfault. For example:
> 
>    virsh net-update default add portgroup "<portgroup default='yes'/>"
> 
> This patch causes virNetworkPortGroupParseXML to fail if no name is
> specified, thus avoiding any later problems.

Looking at the code, I see it's required on more places, yes.  And
according to the documentation the name is needed.

> ---
>  src/conf/network_conf.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c
> index 228951d..6ce2e63 100644
> --- a/src/conf/network_conf.c
> +++ b/src/conf/network_conf.c
> @@ -1175,6 +1175,12 @@ virNetworkPortGroupParseXML(virPortGroupDefPtr def,
>  
>      /* grab raw data from XML */
>      def->name = virXPathString("string(./@name)", ctxt);
> +    if (!def->name) {
> +        virReportError(VIR_ERR_XML_ERROR, "%s",
> +                       _("Missing required name attribute in portgroup"));
> +        goto error;
> +    }
> +
>      isDefault = virXPathString("string(./@default)", ctxt);
>      def->isDefault = isDefault && STRCASEEQ(isDefault, "yes");
>  
> 

Just a question; there's a similar check for (!def->name), for networks
particularly, and that one uses VIR_ERR_NO_NAME (specified as a error
for missing _domain_ name).  Should one of these be changed (in a
separate patch, of course)?
Anyway, ACK for this one,

Martin