[libvirt] [PATCH] Clear/invalidate partially parsed UUIDs

[Matthias Bolte]

2010/5/26 Stefan Berger <stefanb at linux.vnet.ibm.com>:
> Getting paranoid now... Clear possibly partially parsed UUIDs. Question
> is whether to do this in the parsing function itself.
>
> Signed-off-by: Stefan Berger <stefanb at us.ibm.com>
>
> ---
>  src/util/uuid.c |    7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> Index: libvirt-acl/src/util/uuid.c
> ===================================================================
> --- libvirt-acl.orig/src/util/uuid.c
> +++ libvirt-acl/src/util/uuid.c
> @@ -289,14 +289,19 @@ virSetHostUUIDStr(const char *uuid)
>         if (!getDMISystemUUID(dmiuuid, sizeof(dmiuuid))) {
>             if (!virUUIDParse(dmiuuid, host_uuid))
>                 return 0;
> +            // clear partially parsed UUID
> +            memset(host_uuid, 0x0, sizeof(host_uuid));
>         }
>
>         if (!virUUIDIsValid(host_uuid))
>             return virUUIDGenerate(host_uuid);
>     } else {
>         rc = virUUIDParse(uuid, host_uuid);
> -        if (rc)
> +        if (rc) {
> +            // clear partially parsed UUID
> +            memset(host_uuid, 0x0, sizeof(host_uuid));
>             return rc;
> +        }
>         if (!virUUIDIsValid(host_uuid))
>             return EINVAL;
>     }
>

If we want to be paranoid we should do the memset in virUUIDParse itself.

I just grepped for virUUIDParse and found issue: virUUIDParse is used
in some places without checking the return value.

Matthias