Re: [PATCH v1 0/2] doc/admin-guide: update perf-security.rst with CAP_PERFMON usage flows

From: Arnaldo Carvalho de Melo
Date: Tue Oct 20 2020 - 08:01:32 EST


Em Mon, Oct 19, 2020 at 08:15:14PM +0300, Alexey Budankov escreveu:
>
> Assignment of CAP_PERFMON [1] Linux capability to an executable located
> on a file system requires extended attributes (xattrs) [2] to be supported
> by the file system. Even if the file system supports xattrs an fs device
> should be mounted with permission to use xattrs for files located on the
> device (e.g. without nosuid option [3]). No xattrs support and nosuid
> mounts are quite common in HPC and Cloud multiuser environments thus
> applicability of privileged Perf user groups based on file capabilities
> [4] is limited in that environments. Alternative method to confer Linux
> capabilities into a process does still exist and it is thru creation of
> capabilities-enabled-semi-privileged shell environment. Usage of this
> method to extend privileged Perf user groups approach is documented in
> this patch set as an extension to perf-security.rst admin guide file.
>
> [1] https://man7.org/linux/man-pages/man7/capabilities.7.html
> [2] https://man7.org/linux/man-pages/man7/xattr.7.html
> [3] https://man7.org/linux/man-pages/man8/mount.8.html
> [4] https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html#privileged-perf-users-groups



Thanks, applied.

- Arnaldo


> ---
> Alexey Budankov (2):
> doc/admin-guide: note credentials consolidation under CAP_PERFMON
> doc/admin-guide: document creation of CAP_PERFMON privileged shell
>
> Documentation/admin-guide/perf-security.rst | 81 ++++++++++++++++++---
> 1 file changed, 70 insertions(+), 11 deletions(-)
>
> --
> 2.24.1
>

--

- Arnaldo