CVE-2021-46971

CVE-2021-46971 is a low-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 3.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

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.

Frequently asked questions

What is CVE-2021-46971?
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.
How severe is CVE-2021-46971?
CVE-2021-46971 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-46971 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-46971?
CVE-2021-46971 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-46971?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2021-46971 have an EU (EUVD) identifier?
Yes. CVE-2021-46971 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-33619.
When was CVE-2021-46971 published?
CVE-2021-46971 was published on 2024-02-27 and last updated on 2026-06-17.

References

Affected products (1)

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