CVE-2021-46971

Source
https://nvd.nist.gov/vuln/detail/CVE-2021-46971
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-46971.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2021-46971
Related
Published
2024-02-27T19:04:07Z
Modified
2024-09-11T02:00:05Z
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved:

perf/core: Fix unconditional securitylockeddown() call

Currently, the lockdown state is queried unconditionally, even though its result is used only if the PERFSAMPLEREGSINTR bit is set in attr.sampletype. While that doesn't matter in case of the Lockdown LSM, it causes trouble with the SELinux's lockdown hook implementation.

SELinux implements the locked_down hook with a check whether the current task's type has the corresponding "lockdown" class permission ("integrity" or "confidentiality") allowed in the policy. This means that calling the hook when the access control decision would be ignored generates a bogus permission check and audit record.

Fix this by checking sample_type first and only calling the hook when its result would be honored.

References

Affected packages

Debian:11 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
5.10.38-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:12 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
5.10.38-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:13 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
5.10.38-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}