CVE-2024-0564 Kernel: max page sharing of kernel samepage merging (ksm) may cause memory deduplication
Description
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.
CVSS 3.1 detail
Vector CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NExploitable from the adjacent network, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.
- Attack vector
- Adjacent network
- Attack complexity
- High
- Privileges required
- None
- Interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 6 | Versions not published | |
| Red Hat Enterprise Linux 7 | Versions not published | |
| Red Hat Enterprise Linux 8 | Versions not published | |
| Red Hat Enterprise Linux 9 | Versions not published |