powerpc/pseries/dlpar: Fix a missing check in dlpar_parse_cc_property()

In dlpar_parse_cc_property(), 'prop->name' is allocated by kstrdup().
kstrdup() may return NULL, so it should be checked and handle error.
And prop should be freed if 'prop->name' is NULL.
Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

CVE-2019-12614

(cherry picked from commit efa9ace6)
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/powerpc/platforms/pseries/dlpar.c

@@ -55,6 +55,10 @@ static struct property *dlpar_parse_cc_property(struct cc_workarea *ccwa)
 
 	name = (char *)ccwa + be32_to_cpu(ccwa->name_offset);
 	prop->name = kstrdup(name, GFP_KERNEL);
+	if (!prop->name) {
+		dlpar_free_cc_property(prop);
+		return NULL;
+	}
 
 	prop->length = be32_to_cpu(ccwa->prop_length);
 	value = (char *)ccwa + be32_to_cpu(ccwa->prop_offset);