[libvirt] [PATCH] Don't autogenerate seclabels of type 'none'

[Erik Skultety]

On Mon, Aug 14, 2017 at 06:07:10PM -0600, Jim Fehlig wrote:
> When security drivers are active and domain def contains
> no <seclabel> elements, there is no need to autogenerate
> seclabels when starting the domain, e.g.
>
>   <seclabel type='none' model='apparmor'/>
>
> In fact, autogenerating the label can result in needless
> save/restore and migration failures when the security driver
> is not active on the restore/migration target.
>
> The virSecurityManagerGenLabel function in src/security_manager.c
> even has logic to skip autogenerated labels, but the logic
> is a bit flawed. Autogeneration should be skipped when the
> domain has not seclabels, i.e. vm->nseclabels == 0.
>
> Resolves: https://bugzilla.opensuse.org/show_bug.cgi?id=1051017
> Signed-off-by: Jim Fehlig <jfehlig at suse.com>
> ---
>  src/security/security_manager.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/security/security_manager.c b/src/security/security_manager.c
> index 013bbc37e..441c4d1fd 100644
> --- a/src/security/security_manager.c
> +++ b/src/security/security_manager.c
> @@ -670,7 +670,7 @@ virSecurityManagerGenLabel(virSecurityManagerPtr mgr,
>                  virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
>                                 _("Unconfined guests are not allowed on this host"));
>                  goto cleanup;
> -            } else if (vm->nseclabels && generated) {
> +            } else if (vm->nseclabels == 0 && generated) {

This would likely cause a regression like we did prior to commit e4a28a3281
which introduced the condition you're changing, IOW if you specify a seclabel
specifically, you're still going to autogenerate one of type='none'. So my
question is, what's the point of autogenerating seclabel of type='none' anyway?
Shouldn't we just skip type='none' altogether when it's us who generated it?

Erik