[libvirt] [PATCH] Fix a crash when using Open vSwitch virtual ports

[Laine Stump]

On 08/30/2012 01:32 AM, Eric Blake wrote:
> [...]
> That is, I think the real patch here would be simply this (untested)
> version:
>
> diff --git i/src/util/virnetdevopenvswitch.c
> w/src/util/virnetdevopenvswitch.c
> index b903ae4..e8b9f4a 100644
> --- i/src/util/virnetdevopenvswitch.c
> +++ w/src/util/virnetdevopenvswitch.c
> @@ -59,7 +59,7 @@ int virNetDevOpenvswitchAddPort(const char *brname,
> const char *ifname,
>      char *ifaceid_ex_id = NULL;
>      char *profile_ex_id = NULL;
>      char *vmid_ex_id = NULL;
> -    virBufferPtr buf;
> +    virBufferPtr buf = NULL;
>
>      virMacAddrFormat(macaddr, macaddrstr);
>      virUUIDFormat(ovsport->interfaceID, ifuuidstr);
> @@ -79,7 +79,7 @@ int virNetDevOpenvswitchAddPort(const char *brname,
> const char *ifname,
>                          ovsport->profileID) < 0)
>              goto out_of_memory;
>      }
> -    if (virtVlan) {
> +    if (virtVlan && virtVlan->tag[0]) {

If you were to believe that virtVlan might be sent with no tags (which
isn't the case with my patch applied...), then checking for non-0
virtVLan->tag[0] without checking for non-NULL virtVlan->tag would
itself lead to a crash.