Re: [PATCH 3/4] AUDIT: audit when fcaps increase the permitted or inheritable capabilities

Andrew G. Morgan
2008-10-23T04:13:59Z

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Serge E. Hallyn wrote:
>>> ... except if (!issecure(SECURE_NOROOT) && uid==0) I guess?
>>>
>>> And then it also might be interesting in the case where
>>> (!issecure(SECURE_NOROOT) && uid==0) and pP is not full.
>> I guess so, although this seems like a case of being interested in a
>> (unusual) non-privileged execve().
>
> I'm not sure what you mean - but this can only happen if bits are taken
> out of the capability bounding set, right?

Yes, it can happen as you say.

This is a case of an unprivileged uid==0 execution. Since we don't
appear to want to audit other non-privileged execve()s, its not clear to
me that this one deserves attention.

>>>>> rc = bprm_caps_from_vfs_caps(&vcaps, bprm);
>>>>>
>>>>> + audit_log_bprm_fcaps(bprm, &vcaps);
>>>>> +
>>>> When rc != 0, the execve() will fail. Is it appropriate to log in this case?
>>> It might fail because fP contains bits not in pP', right? That's
>>> probably interesting to auditors.
>> In which case, how is the fact it didn't execute captured in the audit log?
>
> I assume as a FAIL? (Not sure of the exact wording in the logs)

OK. As long as its clearly identified as a failure and the logs are not
misleading - making it look like the execve() succeeded with privilege -
then I'm not as concerned.

Cheers

Andrew
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