CVE-2024-0564 Kernel: max page sharing of kernel samepage merging (ksm) may cause memory deduplication

2024-01-3015:01:08

redhat

www.cve.org

linux kernel

memory deduplication

side channel

memory leak

version 4.4.0-96.119

5.3 Medium

CVSS3

Attack Vector

ADJACENT

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

6.2 Medium

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

20.9%

JSON

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.

CNA Affected

[
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        "status": "unaffected",
        "version": "0",
        "lessThan": "4.4.0-96.119",
        "versionType": "semver"
      }
    ],
    "packageName": "kernel",
    "collectionURL": "https://git.kernel.org/pub/scm/linux/kernel",
    "defaultStatus": "affected"
  },
  {
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 6",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "packageName": "kernel",
    "defaultStatus": "unknown",
    "cpes": [
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  {
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    "product": "Red Hat Enterprise Linux 7",
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    "defaultStatus": "unknown",
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:7"
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    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 7",
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    "packageName": "kernel-rt",
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  {
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    "product": "Red Hat Enterprise Linux 8",
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]