The MITRE CVE dictionary describes this issue as:
Systems with microprocessors utilizing speculative execution and Intel software guard extensions (Intel SGX) may allow unauthorized disclosure of information residing in the L1 data cache from an enclave to an attacker with local user access via a side-channel analysis.
Find out more about CVE-2018-3615 from the
MITRE CVE dictionary dictionary and
Not vulnerable. This issue did not affect the versions of kernel as shipped with any Red Hat product.