Messages in this thread | | | Subject | Re: [PATCH 08/28] SECURITY: Allow kernel services to override LSM settings for task actions [try #2] | From | Stephen Smalley <> | Date | Tue, 15 Jan 2008 09:56:42 -0500 |
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On Mon, 2008-01-14 at 14:01 +0000, David Howells wrote: > Stephen Smalley <sds@tycho.nsa.gov> wrote: > > > > avc_has_perm(daemon_tsec->sid, nominated_sid, > > > SECCLASS_CACHE, CACHE__USE_AS_OVERRIDE, NULL); > > > > > > And I assume this doesn't care if one, the other or both of the two SIDs > > > mentioned are of SECCLASS_PROCESS rather than of SECCLASS_CACHE. > > > > Right, the latter is reasonable. > > Okay... It looks like I want four security operations/hooks for cachefiles: > > (1) Check that a daemon can nominate a secid for use by the kernel to override > the process subjective secid. > > (2) Set the secid mentioned in (1). > > (3) Check that the kernel may create files as a particular secid (this could > be specified indirectly by specifying an inode, which would hide the secid > inside the LSM).
I don't think this check is on the kernel per se but rather the ability of the daemon to nominate a secid for use on files created later by the kernel module.
> (4) Set the fscreate secid mentioned in (3). > > Now, it's possible to condense (1) and (2) into a single op, and condense (3) > and (4) into a single op. That, however, might make the ops unusable by nfsd, > which may well want to bypass the checks or do them elsewhere. > > Any thoughts?
I think it is fine to combine them.
-- Stephen Smalley National Security Agency
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