Messages in this thread | | | Subject | Re: [PATCH v6 01/10] capabilities: introduce CAP_PERFMON to kernel and user space | From | Stephen Smalley <> | Date | Thu, 6 Feb 2020 13:30:56 -0500 |
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On 2/6/20 1:26 PM, Alexey Budankov wrote: > > On 06.02.2020 21:23, Stephen Smalley wrote: >> On 2/5/20 12:30 PM, Alexey Budankov wrote: >>> >>> Introduce CAP_PERFMON capability designed to secure system performance >>> monitoring and observability operations so that CAP_PERFMON would assist >>> CAP_SYS_ADMIN capability in its governing role for performance monitoring >>> and observability subsystems. >>> >>> CAP_PERFMON hardens system security and integrity during performance >>> monitoring and observability operations by decreasing attack surface that >>> is available to a CAP_SYS_ADMIN privileged process [2]. Providing the access >>> to system performance monitoring and observability operations under CAP_PERFMON >>> capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes >>> chances to misuse the credentials and makes the operation more secure. >>> Thus, CAP_PERFMON implements the principal of least privilege for performance >>> monitoring and observability operations (POSIX IEEE 1003.1e: 2.2.2.39 principle >>> of least privilege: A security design principle that states that a process >>> or program be granted only those privileges (e.g., capabilities) necessary >>> to accomplish its legitimate function, and only for the time that such >>> privileges are actually required) >>> >>> CAP_PERFMON meets the demand to secure system performance monitoring and >>> observability operations for adoption in security sensitive, restricted, >>> multiuser production environments (e.g. HPC clusters, cloud and virtual compute >>> environments), where root or CAP_SYS_ADMIN credentials are not available to >>> mass users of a system, and securely unblocks accessibility of system performance monitoring and observability operations beyond root and CAP_SYS_ADMIN use cases. >>> >>> CAP_PERFMON takes over CAP_SYS_ADMIN credentials related to system performance >>> monitoring and observability operations and balances amount of CAP_SYS_ADMIN >>> credentials following the recommendations in the capabilities man page [1] >>> for CAP_SYS_ADMIN: "Note: this capability is overloaded; see Notes to kernel >>> developers, below." For backward compatibility reasons access to system >>> performance monitoring and observability subsystems of the kernel remains >>> open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN capability >>> usage for secure system performance monitoring and observability operations >>> is discouraged with respect to the designed CAP_PERFMON capability. >>> >>> Although the software running under CAP_PERFMON can not ensure avoidance >>> of related hardware issues, the software can still mitigate these issues >>> following the official hardware issues mitigation procedure [2]. The bugs >>> in the software itself can be fixed following the standard kernel development >>> process [3] to maintain and harden security of system performance monitoring >>> and observability operations. >>> >>> [1] http://man7.org/linux/man-pages/man7/capabilities.7.html >>> [2] https://www.kernel.org/doc/html/latest/process/embargoed-hardware-issues.html >>> [3] https://www.kernel.org/doc/html/latest/admin-guide/security-bugs.html >>> >>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> >> >> This will require a small update to the selinux-testsuite to correctly reflect the new capability requirements, but that's easy enough. > > Is the suite a part of the kernel sources or something else?
It is external, https://github.com/SELinuxProject/selinux-testsuite
I wasn't suggesting that your patch be blocked on updating the testsuite, just noting that it will need to be done.
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