CVE-2020-8834Context Switching Race Condition in Kernel

Severity
6.5MEDIUMNVD
OSV7.1OSV5.5
EPSS
0.1%
top 74.46%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedApr 9
Latest updateAug 13

Description

KVM in the Linux kernel on Power8 processors has a conflicting use of HSTATE_HOST_R1 to store r1 state in kvmppc_hv_entry plus in kvmppc_{save,restore}_tm, leading to a stack corruption. Because of this, an attacker with the ability run code in kernel space of a guest VM can cause the host kernel to panic. There were two commits that, according to the reporter, introduced the vulnerability: f024ee098476 ("KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures") 87a11bb6a7f7

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:HExploitability: 2.0 | Impact: 4.0

Affected Packages5 packages

CVEListV5linux_kernel/linux_kernel4.8unspecified+1
Debianlinux/linux_kernel< 4.18.6-1+3
Ubuntulinux/linux_kernel< 4.15.0-96.97
Ubuntugnome/libcroco< 0.6.13-1ubuntu0.1+3
NVDopensuse/leap15.1

Also affects: Ubuntu Linux 16.04, 18.04

🔴Vulnerability Details

6
OSV
libcroco vulnerabilities2024-08-13
GHSA
GHSA-7fx7-755p-qmjj: KVM in the Linux kernel on Power8 processors has a conflicting use of HSTATE_HOST_R1 to store r1 state in kvmppc_hv_entry plus in kvmppc_{save,restore2022-05-24
OSV
libcroco vulnerabilities2022-04-26
CVEList
Linux kernel KVM Power8 conflicting use of HSTATE_HOST_R12020-04-09
OSV
CVE-2020-8834: KVM in the Linux kernel on Power8 processors has a conflicting use of HSTATE_HOST_R1 to store r1 state in kvmppc_hv_entry plus in kvmppc_{save,restore2020-04-09

📋Vendor Advisories

3
Ubuntu
Linux kernel vulnerabilities2020-04-06
Red Hat
Kernel: ppc: kvm: conflicting use of HSTATE_HOST_R1 to store r1 state leads to host stack corruption2020-04-06
Debian
CVE-2020-8834: linux - KVM in the Linux kernel on Power8 processors has a conflicting use of HSTATE_HOS...2020

💬Community

2
Bugzilla
CVE-2020-8834 kernel: conflicting use of HSTATE_HOST_R1 to store r1 state in kvmppc_hv_entry in KVM leads to stack corruption [fedora-all]2020-04-07
Bugzilla
CVE-2020-8834 Kernel: ppc: kvm: conflicting use of HSTATE_HOST_R1 to store r1 state leads to host stack corruption2020-04-01