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…
Does this matter?
Lower severity and a low EPSS score (0.23%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 3.3 LOWCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 0.23% probability · 14th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9bPatch
- https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1cePatch
- https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ffPatch
- https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1Patch
- https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895ePatch
- https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9bPatch
- https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1cePatch
- https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ffPatch
- https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1Patch
- https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895ePatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.