Linux Kernel up to 5.4.116/5.10.34/5.11.18/5.12.1 perf security_locked_down access control

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 5.4.116/5.10.34/5.11.18/5.12.1. This vulnerability affects the function security_locked_down of the component perf. Executing a manipulation can lead to access control. This vulnerability is registered as CVE-2021-46971. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.4.116/5.10.34/5.11.18/5.12.1 (Operating System). It has been declared as critical. This vulnerability affects the function security_locked_down of the component perf. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix unconditional security_locked_down() call Currently, the lockdown state is queried unconditionally, even though its result is used only if the PERF_SAMPLE_REGS_INTR bit is set in attr.sample_type. 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.

The weakness was published 02/27/2024. The advisory is available at git.kernel.org. This vulnerability was named CVE-2021-46971. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1068 by the MITRE ATT&CK project.

Upgrading to version 5.4.117, 5.10.35, 5.11.19, 5.12.2 or 5.13 eliminates this vulnerability. Applying the patch b246759284d6/4348d3b5027b/f5809ca4c311/c7b0208ee370/08ef1af4de5f is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.4.116
• 5.10.0
• 5.10.1
• 5.10.2
• 5.10.3
• 5.10.4
• 5.10.5
• 5.10.6
• 5.10.7
• 5.10.8
• 5.10.9
• 5.10.10
• 5.10.11
• 5.10.12
• 5.10.13
• 5.10.14
• 5.10.15
• 5.10.16
• 5.10.17
• 5.10.18
• 5.10.19
• 5.10.20
• 5.10.21
• 5.10.22
• 5.10.23
• 5.10.24
• 5.10.25
• 5.10.26
• 5.10.27
• 5.10.28
• 5.10.29
• 5.10.30
• 5.10.31
• 5.10.32
• 5.10.33
• 5.10.34
• 5.11.0
• 5.11.1
• 5.11.2
• 5.11.3
• 5.11.4
• 5.11.5
• 5.11.6
• 5.11.7
• 5.11.8
• 5.11.9
• 5.11.10
• 5.11.11
• 5.11.12
• 5.11.13
• 5.11.14
• 5.11.15
• 5.11.16
• 5.11.17
• 5.11.18
• 5.12.0
• 5.12.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

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