Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] ima: avoid appraise error for hash calc interrupt
To:     Patrick Callaghan <patrickc@linux.ibm.com>,
        linux-integrity@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Mimi Zohar <zohar@linux.ibm.com>
References: <20191111192348.30535-1-patrickc@linux.ibm.com>
From:   Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Message-ID: <e3f520ce-a290-206d-8097-b852123357ca@linux.microsoft.com>
Date:   Mon, 11 Nov 2019 14:29:52 -0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.9.0
MIME-Version: 1.0
In-Reply-To: <20191111192348.30535-1-patrickc@linux.ibm.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 11/11/19 11:23 AM, Patrick Callaghan wrote:

> -		if (rbuf_len == 0)
> +		if (rbuf_len == 0) {	/* unexpected EOF */
> +			rc = -EINVAL;
>   			break;
> +		}
>   		offset += rbuf_len;

Should there be an additional check to validate that (offset + rbuf_len) 
is less than i_size before calling cypto_shash_update (since rbuf_len is 
one of the parameters for this call)?

                if ((rbuf_len == 0) || (offset + rbuf_len >= i_size)) {
                         rc = -EINVAL;
                         break;
                }
                offset += rbuf_len;

>   	       rc = crypto_shash_update(shash, rbuf, rbuf_len);

  -lakshmi