[libvirt] [PATCH v2 01/12] conf: Fix possible memleak in capabilities

[Erik Skultety]

On Thu, Apr 06, 2017 at 11:12:54AM +0200, Martin Kletzander wrote:
> On Thu, Apr 06, 2017 at 09:50:49AM +0200, Erik Skultety wrote:
> > On Wed, Apr 05, 2017 at 04:36:24PM +0200, Martin Kletzander wrote:
> > > If formatting NUMA topology fails, the function returns immediatelly,
> > > but the buffer structure allocated on the stack references lot of
> > > heap-allocated memory and that would get lost in such case.
> > >
> > > Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
> > > ---
> > >  src/conf/capabilities.c | 6 +++++-
> > >  1 file changed, 5 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/src/conf/capabilities.c b/src/conf/capabilities.c
> > > index 08907aced1b9..be95c50cfb67 100644
> > > --- a/src/conf/capabilities.c
> > > +++ b/src/conf/capabilities.c
> > > @@ -955,7 +955,7 @@ virCapabilitiesFormatXML(virCapsPtr caps)
> > >      if (caps->host.nnumaCell &&
> > >          virCapabilitiesFormatNUMATopology(&buf, caps->host.nnumaCell,
> > >                                            caps->host.numaCell) < 0)
> > > -        return NULL;
> > > +        goto error;
> >
> > Personally, I'd more like cleanup, but looking at other XML formatting methods,
> > I'm fine with this as well, at least we stay consistent.
> >
> > >
> > >      for (i = 0; i < caps->host.nsecModels; i++) {
> > >          virBufferAddLit(&buf, "<secmodel>\n");
> > > @@ -1072,6 +1072,10 @@ virCapabilitiesFormatXML(virCapsPtr caps)
> > >          return NULL;
> > >
> >
> > Git discarded the context here, so squash this in:
> >
> > diff --git a/src/conf/capabilities.c b/src/conf/capabilities.c
> > index be95c50cf..ea6d4b19d 100644
> > --- a/src/conf/capabilities.c
> > +++ b/src/conf/capabilities.c
> > @@ -1069,7 +1069,7 @@ virCapabilitiesFormatXML(virCapsPtr caps)
> >     virBufferAddLit(&buf, "</capabilities>\n");
> >
> >     if (virBufferCheckError(&buf) < 0)
> > -        return NULL;
> > +        goto error;
> >
> >     return virBufferContentAndReset(&buf);
> >
>
> I don't really understand why would I need to do that.

Because buf->content might be non-NULL.

>
> >
> > >      return virBufferContentAndReset(&buf);
> > > +
> > > + error:
> > > +    virBufferFreeAndReset(&buf);
> > > +    return NULL;
> > >  }
> > >
> > >  /* get the maximum ID of cpus in the host */
> > > --
> > > 2.12.2
> > >
> >
> > ACK with the bit above squashed in.
> >
> > Erik