Out-of-bounds read in Linux kernel - CVE-2021-38166

 

Out-of-bounds read in Linux kernel - CVE-2021-38166

Published: August 7, 2021 / Updated: April 1, 2022


Vulnerability identifier: #VU90365
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-38166
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to execute arbitrary code.

The vulnerability exists due to an out-of-bounds read error within the kvmalloc() function in kernel/bpf/hashtab.c. A local user can execute arbitrary code.


Affected software

Linux kernel
SUSE MicroOS
SUSE Linux Enterprise Module for Public Cloud
SUSE Linux Enterprise Workstation Extension
SUSE Linux Enterprise Module for Live Patching
SUSE Linux Enterprise Module for Legacy Software
SUSE Linux Enterprise Module for Development Tools
SUSE Linux Enterprise Module for Basesystem
SUSE Linux Enterprise High Availability
Ubuntu
Fedora
kernel-livepatch-SLE15-SP3_Update_6-debugsource
kernel-livepatch-5_3_18-59_24-default-debuginfo
kernel-livepatch-5_3_18-59_24-default
kernel-syms-azure
kernel-devel-azure
kernel-source-azure
kernel-azure-debuginfo
kernel-azure
kernel-azure-devel-debuginfo
kernel-azure-devel
kernel-azure-debugsource
kernel-default
kernel-64kb
kernel-64kb-debuginfo
kernel-64kb-debugsource
kernel-64kb-devel
kernel-64kb-devel-debuginfo
kernel-devel
kernel-macros
kernel-zfcpdump
kernel-preempt
kernel-zfcpdump-debuginfo
kernel-zfcpdump-debugsource
cluster-md-kmp-default
cluster-md-kmp-default-debuginfo
dlm-kmp-default
dlm-kmp-default-debuginfo
gfs2-kmp-default
gfs2-kmp-default-debuginfo
ocfs2-kmp-default
ocfs2-kmp-default-debuginfo
kernel-default-debuginfo
kernel-default-debugsource
kernel-default-devel
kernel-default-extra
kernel-default-extra-debuginfo
kernel-preempt-debuginfo
kernel-preempt-debugsource
kernel-preempt-extra
kernel-preempt-extra-debuginfo
kernel-default-livepatch
kernel-default-livepatch-devel
reiserfs-kmp-default
reiserfs-kmp-default-debuginfo
kernel-obs-build
kernel-obs-build-debugsource
kernel-syms
kernel-preempt-devel
kernel-preempt-devel-debuginfo
kernel-docs
kernel-source
kernel-default-devel-debuginfo
kernel-default-base
linux-image-5.13.0-1014-oem (Ubuntu package)
linux-image-oem-20.04c (Ubuntu package)
kernel

How to mitigate CVE-2021-38166

Install update from vendor's website.

kernel-livepatch-SLE15-SP3_Update_6-debugsource - update to 1-7.5.1
kernel-livepatch-5_3_18-59_24-default-debuginfo - update to 1-7.5.1
kernel-livepatch-5_3_18-59_24-default - update to 1-7.5.1
kernel-syms-azure - update to 5.3.18-38.22.1
kernel-devel-azure - update to 5.3.18-38.22.1
kernel-source-azure - update to 5.3.18-38.22.1
kernel-azure-debuginfo - update to 5.3.18-38.22.2
kernel-azure - update to 5.3.18-38.22.2
kernel-azure-devel-debuginfo - update to 5.3.18-38.22.2
kernel-azure-devel - update to 5.3.18-38.22.2
kernel-azure-debugsource - update to 5.3.18-38.22.2
kernel-default - update to 5.3.18-59.24.1
kernel-64kb - update to 5.3.18-59.24.1
kernel-64kb-debuginfo - update to 5.3.18-59.24.1
kernel-64kb-debugsource - update to 5.3.18-59.24.1
kernel-64kb-devel - update to 5.3.18-59.24.1
kernel-64kb-devel-debuginfo - update to 5.3.18-59.24.1
kernel-devel - update to 5.3.18-59.24.1
kernel-macros - update to 5.3.18-59.24.1
kernel-zfcpdump - update to 5.3.18-59.24.1
kernel-preempt - update to 5.3.18-59.24.1
kernel-zfcpdump-debuginfo - update to 5.3.18-59.24.1
kernel-zfcpdump-debugsource - update to 5.3.18-59.24.1
cluster-md-kmp-default - update to 5.3.18-59.24.1
cluster-md-kmp-default-debuginfo - update to 5.3.18-59.24.1
dlm-kmp-default - update to 5.3.18-59.24.1
dlm-kmp-default-debuginfo - update to 5.3.18-59.24.1
gfs2-kmp-default - update to 5.3.18-59.24.1
gfs2-kmp-default-debuginfo - update to 5.3.18-59.24.1
ocfs2-kmp-default - update to 5.3.18-59.24.1
ocfs2-kmp-default-debuginfo - update to 5.3.18-59.24.1
kernel-default-debuginfo - update to 5.3.18-59.24.1
kernel-default-debugsource - update to 5.3.18-59.24.1
kernel-default-devel - update to 5.3.18-59.24.1
kernel-default-extra - update to 5.3.18-59.24.1
kernel-default-extra-debuginfo - update to 5.3.18-59.24.1
kernel-preempt-debuginfo - update to 5.3.18-59.24.1
kernel-preempt-debugsource - update to 5.3.18-59.24.1
kernel-preempt-extra - update to 5.3.18-59.24.1
kernel-preempt-extra-debuginfo - update to 5.3.18-59.24.1
kernel-default-livepatch - update to 5.3.18-59.24.1
kernel-default-livepatch-devel - update to 5.3.18-59.24.1
reiserfs-kmp-default - update to 5.3.18-59.24.1
reiserfs-kmp-default-debuginfo - update to 5.3.18-59.24.1
kernel-obs-build - update to 5.3.18-59.24.1
kernel-obs-build-debugsource - update to 5.3.18-59.24.1
kernel-syms - update to 5.3.18-59.24.1
kernel-preempt-devel - update to 5.3.18-59.24.1
kernel-preempt-devel-debuginfo - update to 5.3.18-59.24.1
kernel-docs - update to 5.3.18-59.24.1
kernel-source - update to 5.3.18-59.24.1
kernel-default-devel-debuginfo - update to 5.3.18-59.24.1
kernel-default-base - update to 5.3.18-59.24.1.18.12.1
linux-image-5.13.0-1014-oem (Ubuntu package) - update to 5.13.0-1014.18
linux-image-oem-20.04c (Ubuntu package) - update to 5.13.0.1014.18
kernel - addressed in versions 5.13.10-100.fc33, 5.13.10-200.fc34

External References

Related Security Bulletins