lkml.org 
[lkml]   [2021]   [May]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: [PATCH v5 06/12] evm: Ignore INTEGRITY_NOLABEL/INTEGRITY_NOXATTRS if conditions are safe
From
Date
On Mon, 2021-05-03 at 07:55 +0000, Roberto Sassu wrote:
>
> > > diff --git a/security/integrity/evm/evm_main.c
> > b/security/integrity/evm/evm_main.c

> > > @@ -354,6 +372,8 @@ static int evm_protect_xattr(struct dentry *dentry,
> > const char *xattr_name,
> > > -EPERM, 0);
> > > }
> > > out:
> > > + if (evm_ignore_error_safe(evm_status))
> > > + return 0;
> >
> > I agree with the concept, but the function name doesn't provide enough
> > context. Perhaps defining a function more along the lines of
> > "evm_hmac_disabled()" would be more appropriate and at the same time
> > self documenting.
>
> Since the function checks if the passed error can be ignored,
> would evm_ignore_error_hmac_disabled() also be ok?

The purpose of evm_protect_xattr() is to prevent allowing an invalid
security.evm xattr from being re-calculated and updated, making it
valid. Refer to the first line of the function description. That
hasn't changed.

One of the reasons for defining a new function is to avoid code
duplication, but it should not come at the expense of clear and easily
understood code. In this case, the reason for "ignoring" certain
return codes needs to be highlighted, not hidden.
(is_)evm_hmac_disabled() makes this very clear.

Please update the function description to include the reason why making
an exception is safe.

thanks,

Mimi

> > > if (evm_status != INTEGRITY_PASS)
> > > integrity_audit_msg(AUDIT_INTEGRITY_METADATA,
> > d_backing_inode(dentry),
> > > dentry->d_name.name,
> > "appraise_metadata",
\
 
 \ /
  Last update: 2021-05-03 14:08    [W:0.162 / U:0.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site