CVE-2026-63837

A flaw was found in the Linux kernel's Elastic Network Adapter (ENA) driver. The driver's Precision Time Protocol (PTP) Hardware Clock (PHC) support, specifically the ena_phc_gettimex64() function, fails to check the return code of an internal timestamp retrieval function. This oversight can lead to uninitialized or invalid memory being passed to userspace applications through the PTP ioctl, resulting in an information leak. This vulnerability allows a local user to potentially gain access to sensitive system information.

This vulnerability is rated as Moderate severity because it requires local access on systems equipped with Amazon Elastic Network Adapter (ENA) devices and is limited to reading uninitialized kernel stack contents. Exploitation requires an authenticated local attacker to interact with the PTP hardware clock interface on instances utilizing ENA hardware. The flaw cannot be exploited remotely and does not directly allow arbitrary code execution, privilege escalation, or denial of service.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.