CVE-2020-11669

kernel: powerpc: guest can cause DoS on POWER9 KVM hosts

Severity Score

5.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

An issue was discovered in the Linux kernel before 5.2 on the powerpc platform. arch/powerpc/kernel/idle_book3s.S does not have save/restore functionality for PNV_POWERSAVE_AMR, PNV_POWERSAVE_UAMOR, and PNV_POWERSAVE_AMOR, aka CID-53a712bae5dd.

Se detectó un problema en el kernel de Linux versiones anteriores a 5.2, en la plataforma powerpc. El archivo arch/powerpc/kernel/idle_book3s.S no posee la funcionalidad de guardar y restaurar para PNV_POWERSAVE_AMR, PNV_POWERSAVE_UAMOR y PNV_POWERSAVE_AMOR, también se conoce como CID-53a712bae5dd.

A flaw was found in the way Linux kernel running on the Power9 processor saves and restores its registers while going in and coming out of an idle state. The issue occurs when a guest kernel has Kernel Userspace Address Protection (KUAP) feature enabled. The idle_book3s function does not save and restore the Authority Mask Register (AMR), Authority Mask Override Register (AMOR) and User Authority Mask Override Register (UAMOR). A guest user may use this flaw to render the host system unusable resulting in DoS issue.

*Credits: N/A

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Local

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-04-09 CVE Reserved
2020-04-10 CVE Published
2023-03-08 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-393: Return of Wrong Status Code

CAPEC

References (13)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC
http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00035.html	2020-05-28
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=53a712bae5dd919521a58d7bad773b949358add0	2020-05-28
https://github.com/torvalds/linux/commit/53a712bae5dd919521a58d7bad773b949358add0	2020-05-28
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/208660.html	2020-05-28
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/208661.html	2020-05-28
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/208663.html	2020-05-28
https://security.netapp.com/advisory/ntap-20200430-0001	2020-05-28

URL	Date	SRC
https://access.redhat.com/errata/RHSA-2019:3517	2020-05-28
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.2	2020-05-28
https://usn.ubuntu.com/4363-1	2020-05-28
https://usn.ubuntu.com/4368-1	2020-05-28
https://access.redhat.com/security/cve/CVE-2020-11669	2021-04-27
https://bugzilla.redhat.com/show_bug.cgi?id=1824803	2021-04-27

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.2 Search vendor "Linux" for product "Linux Kernel" and version " < 5.2"		-		Affected
Opensuse Search vendor "Opensuse"		Leap Search vendor "Opensuse" for product "Leap"				15.1 Search vendor "Opensuse" for product "Leap" and version "15.1"		-		Affected
Redhat Search vendor "Redhat"		Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux"				7.0 Search vendor "Redhat" for product "Enterprise Linux" and version "7.0"		-		Affected