Re: [PATCH v5 06/12] evm: Ignore INTEGRITY_NOLABEL/INTEGRITY_NOXATTRS if conditions are safe

From: Mimi Zohar
Date: Mon May 03 2021 - 10:34:45 EST


On Mon, 2021-05-03 at 14:15 +0000, Roberto Sassu wrote:

> > > > if (evm_status != INTEGRITY_PASS)
> > > > integrity_audit_msg(AUDIT_INTEGRITY_METADATA,
> > > d_backing_inode(dentry),
> > > > dentry->d_name.name,
> > > "appraise_metadata",
> > > > @@ -515,7 +535,8 @@ int evm_inode_setattr(struct dentry *dentry,
> > struct
> > > iattr *attr)
> > > > return 0;
> > > > evm_status = evm_verify_current_integrity(dentry);
> > > > if ((evm_status == INTEGRITY_PASS) ||
> > > > - (evm_status == INTEGRITY_NOXATTRS))
> > > > + (evm_status == INTEGRITY_NOXATTRS) ||
> > > > + (evm_ignore_error_safe(evm_status)))
> > >
> > > It would also remove the INTEGRITY_NOXATTRS test duplication here.
> >
> > Ok.
>
> Actually, it does not seem a duplication. Currently, INTEGRITY_NOXATTRS
> is ignored also when the HMAC key is loaded.

The existing INTEGRITY_NOXATTRS exemption is more general and includes
the new case of when EVM HMAC is disabled. The additional exemption is
only needed for INTEGRITY_NOLABEL, when EVM HMAC is disabled.

Mimi