PT-2018-2601 · Linux+5 · Linux Kernel+5

Zhipeng Xie · Published 2018-04-06 · Updated 2023-08-16 · CVE-2018-20784

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 4.20.2

Description The issue is related to the implementation of the update blocked averages() function in the Linux kernel, which can lead to an infinite loop due to an unreachable exit condition. This can be exploited by a remote attacker to cause a denial of service. The vulnerability is caused by the mishandling of leaf cfs rq's in the kernel/sched/fair.c file, allowing attackers to induce a high load and potentially have other unspecified impacts.

Recommendations For Linux kernel versions prior to 4.20.2, update to version 4.20.2 or later to resolve the issue. As a temporary workaround, consider restricting system load to minimize the risk of exploitation.

Fix

DoS

Infinite Loop

Weakness Enumeration

CWE-835

Related Identifiers

ALT-PU-2018-1557

ALT-PU-2019-1046

ALT-PU-2019-1048

ALT-PU-2019-1139

BDU:2019-01113

CESA-2019_1959

CESA-2019_1971

CVE-2018-20784

RHSA-2019:1959

RHSA-2019:1971

RHSA-2019_1959

RHSA-2019_1971

SUSE-SU-2022:2077-1

SUSE-SU-2022:2082-1

SUSE-SU-2023:2805-1

SUSE-SU-2023:3324-1

USN-4115-1

USN-4115-2

USN-4118-1

USN-4211-1

USN-4211-2

Affected Products

Alt Linux

Centos

Linux Kernel

Red Hat

Suse

Ubuntu

References · 287

• https://github.com/torvalds/linux/commit/c40f7d74c741a907cfaeb73a7697081881c497d0 · Patch
• https://ubuntu.com/security/CVE-2018-14610 · Vendor Advisory
• https://ubuntu.com/security/CVE-2018-13097 · Vendor Advisory
• https://ubuntu.com/security/CVE-2018-14615 · Vendor Advisory
• https://ubuntu.com/security/CVE-2019-9506 · Vendor Advisory
• https://ubuntu.com/security/CVE-2019-17075 · Vendor Advisory
• https://ubuntu.com/security/CVE-2019-11085 · Vendor Advisory
• https://usn.ubuntu.com/4115-1 · Vendor Advisory
• https://access.redhat.com/errata/RHSA-2019:1971 · Vendor Advisory
• https://ubuntu.com/security/CVE-2019-12818 · Vendor Advisory
• https://usn.ubuntu.com/4118-1 · Vendor Advisory
• https://osv.dev/vulnerability/USN-4115-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2018-20784 · Security Note
• https://ubuntu.com/security/CVE-2019-3900 · Vendor Advisory
• https://ubuntu.com/security/CVE-2018-16862 · Vendor Advisory