Public on 2024-01-30
Modified on 2024-02-01
A flaw was found in the Linux kernel's memory deduplication mechanism. The max page sharing of Kernel Samepage Merging (KSM), added in Linux kernel version 4.4.0-96.119, can create a side channel. When the attacker and the victim share the same host and the default setting of KSM is "max page sharing=256", it is possible for the attacker to time the unmap to merge with the victim's page. The unmapping time depends on whether it merges with the victim's page and additional physical pages are created beyond the KSM's "max page share". Through these operations, the attacker can leak the victim's page.
Medium severity
CVSS v3 Base Score
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 1 kernel No Fix Planned
Amazon Linux 2 - Core kernel Pending Fix
Amazon Linux 2 - Kernel-5.10 Extra kernel Pending Fix
Amazon Linux 2 - Kernel-5.4 Extra kernel Pending Fix
Amazon Linux 2 - Kernel-5.15 Extra kernel Not Affected
Amazon Linux 2023 kernel Not Affected

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 4.7 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N