Messages in this thread | | | Subject | Re: [PATCH v2 1/2] Documentation/admin-guide: introduce perf-security.rst file | From | Alexey Budankov <> | Date | Mon, 26 Nov 2018 11:57:21 +0300 |
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Hello Jon,
On 25.11.2018 22:47, Jonathan Corbet wrote: > On Wed, 21 Nov 2018 12:14:14 +0300 > Alexey Budankov <alexey.budankov@linux.intel.com> wrote: > >> +For the purpose of performing security checks Linux implementation splits >> +processes into two categories [6]_ : a) privileged processes (whose effective >> +user ID is 0, referred to as superuser or root), and b) unprivileged processes >> +(whose effective UID is nonzero). > > Is that really what's going on here? If I understand things correctly, > it's looking for CAP_SYS_PTRACE rather than a specific UID; am I missing > something here?
You are right regarding CAP_SYS_PTRACE but this capability is not the only one which is used by perf_events for security checks, so the capabilities clarification is kept aside of these patches, because patches initial intention is to clarify security specifics of sysctl_perf_even_paranoid settings.
I agree that the document can be extended with details clarifying capabilities used by perf_events for security checks.
> > (Also, you would want "*the* Linux implementation" in the first sentence > above).
Accepted.
> > One other thing: > >> +(whose effective UID is nonzero). Privileged processes bypass all kernel >> +security permission checks so perf_events performance monitoring is fully >> +available to privileged processes without *access*, *scope* and *resource* >> +restrictions. > > Could I ask for a slight toning down of the markup here? There's a lot of > *emphasis* here that isn't really needed and tends to get in the way.
Accepted.
Thanks, Alexey
> > Thanks, > > jon >
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