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Subject: Re: [PATCH 1/2] integrity: Add errno field in audit message
To:     Mimi Zohar <zohar@linux.ibm.com>, sgrubb@redhat.com,
        paul@paul-moore.com
Cc:     rgb@redhat.com, linux-integrity@vger.kernel.org,
        linux-audit@redhat.com, linux-kernel@vger.kernel.org
References: <20200611000400.3771-1-nramas@linux.microsoft.com>
 <1591989920.11061.90.camel@linux.ibm.com>
From:   Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Message-ID: <42482562-d74c-2678-069f-1d8ef4feffac@linux.microsoft.com>
Date:   Fri, 12 Jun 2020 12:50:14 -0700
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On 6/12/20 12:25 PM, Mimi Zohar wrote:

> The idea is a good idea, but you're assuming that "result" is always
> errno.  That was probably true originally, but isn't now.  For
> example, ima_appraise_measurement() calls xattr_verify(), which
> compares the security.ima hash with the calculated file hash.  On
> failure, it returns the result of memcmp().  Each and every code path
> will need to be checked.
> 

Good catch Mimi.

Instead of "errno" should we just use "result" and log the value given 
in the result parameter?

 From the audit field dictionary (link given below) "result" is already 
a known field that is used to indicate the result of the audited operation.

@Steve\Paul:
Like "res" is "result" also expected to have only values "0" or "1", or 
can it be any result code?

https://github.com/linux-audit/audit-documentation/blob/master/specs/fields/field-dictionary.csv

res 	alphanumeric 	result of the audited operation(success/fail) 	

result 	alphanumeric 	result of the audited operation(success/fail)

thanks,
  -lakshmi