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SubjectRe: [PATCH] ima: avoid appraise error for hash calc interrupt
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On 11/12/2019 9:14 AM, Mimi Zohar wrote:

> On Mon, 2019-11-11 at 14:29 -0800, Lakshmi Ramasubramanian wrote:
>> 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)?
>
> The "while" statement enforces that.
>
> Mimi

Yes - but that check happens after the call to crypto_shash_update().

Perhaps integrity_kernel_read() will never return (rbuf_len) that will
=> violate the check in the "while" statement.
=> number of bytes read that is greater than the memory allocated for
rbuf even in error conditions.

Just making sure.

thanks,
-lakshmi

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

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