SB20260720431 - Use of Uninitialized Variable in Linux kernel amazon ena driver

Description

This security bulletin contains information about 1 vulnerability.

1) Use of Uninitialized Variable (CVE-ID: CVE-2026-63837)

CWE-ID: CWE-457 - Use of Uninitialized Variable

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to use of uninitialized memory in ena_phc_gettimex64() when handling a PTP ioctl after ena_com_phc_get_timestamp() returns an error. A local user can invoke the affected ioctl to disclose sensitive information.

The issue can occur when PHC is disabled or in a blocked state, and invalid hardware values may also be exposed to userspace.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/24a08d7d6218d60c033015cf4870b6096446e734
• https://git.kernel.org/stable/c/bddf59818ae5102e6d82a4dae5add6df8da38fb0
• https://git.kernel.org/stable/c/edcb049d836e175e7b3d5e0d05657104545b5e65