[libvirt PATCH 5/6] src: don't use VIR_FREE on an object allocation

[Michal Privoznik]

On 5/19/20 7:41 PM, Daniel P. Berrangé wrote:
> Memory allocated using g_object_new must never be released using
> VIR_FREE/g_free because g_object_new uses a special allocation
> strategy internally.
> 
> Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
> ---
>   src/rpc/virnettlscontext.c | 5 +----
>   1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/src/rpc/virnettlscontext.c b/src/rpc/virnettlscontext.c
> index 02c17124a1..ced0cbdcd8 100644
> --- a/src/rpc/virnettlscontext.c
> +++ b/src/rpc/virnettlscontext.c
> @@ -750,12 +750,9 @@ static virNetTLSContextPtr virNetTLSContextNew(const char *cacert,
>       return ctxt;
>   
>    error:
> +    virObjectUnref(ctxt);
>       if (isServer)
>           gnutls_dh_params_deinit(ctxt->dhParams);
> -    if (ctxt->x509cred)
> -        gnutls_certificate_free_credentials(ctxt->x509cred);
> -    VIR_FREE(ctxt->priority);
> -    VIR_FREE(ctxt);

The unref call needs to go exactly here, where you remove these lines, 
because at the point we jump onto the error label, @ctxt has exactly one 
reference. And if you decrease it, the object is freed and the 
subsequent call to gnutls_whatever() would deref invalid pointer.

Michal