Policies rules generated using "audit2allow -R" questions (risks)

[Todd Sandor]

I'm a selinux newbie using RHEL7.9 and I'm in the process of creating
a "private/application" selinux policy for a
large legacy application.

For some AVCs/denials I've been using the audit2allow to generate some
of the rules/interfaces to resolve the AVCs/denials.

Questions about using the "-R" option to generate the policy rules:

1. What are the risks of using the "-R" option?
Do people use the "interfaces" which the "-R" generates in the
policies deployed in production environments?
When "-R" is used, how does the tool itself determine which
"interface" to use?   Is it Linux distribution and release specific so
if we upgrade will it be a problem?

The redhat documentation and man page (and other vendor's
documentation) specify it is a risk to use this tool (see [1][2]).

2. When the "-R" option is not used, separate rules are generated that
do not include "interface" rules.
Is it safe to use the rules audit2allow generates (without "-R") or
are those a risk as well?

3. Any other suggestions for resolving AVCs/denials ?

[1]
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/htm...

[2] audit2allow man page
man audit2allow
...
       -R | --reference
              Generate reference policy using installed macros.  This
attempts to match denials  against  interfaces  and  may  be
              inaccurate.

Thanks

[justina colmena ~biz]

"Large legacy application."

I'm running for the nearest exit and getting off the property already.

On July 23, 2021 8:49:25 AM AKDT, Todd Sandor  wrote:
> I'm a selinux newbie using RHEL7.9 and I'm in the process of creating
> a "private/application" selinux policy for a
> large legacy application.
>
> For some AVCs/denials I've been using the audit2allow to generate some
> of the rules/interfaces to resolve the AVCs/denials.
>
> Questions about using the "-R" option to generate the policy rules:
> What are the risks of using the "-R" option?
>
> Do people use the "interfaces" which the "-R" generates in the
> policies deployed in production environments?
> When "-R" is used, how does the tool itself determine which
> "interface" to use?   Is it Linux distribution and release specific so
> if we upgrade will it be a problem?
>
> The redhat documentation and man page (and other vendor's
> documentation) specify it is a risk to use this tool (see [1][2]).
> When the "-R" option is not used, separate rules are generated that
>
> do not include "interface" rules.
> Is it safe to use the rules audit2allow generates (without "-R") or
> are those a risk as well?
> Any other suggestions for resolving AVCs/denials ?
>
> [1]
> https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/htm...
>
> [2] audit2allow man page
> man audit2allow
> ...
>       -R | --reference
>              Generate reference policy using installed macros.  This
> attempts to match denials  against  interfaces  and  may  be
>              inaccurate.
>
> Thanks