Re: [PATCH] crypto: hash.h: Prevent use of req->digest in ahash update
From: Kamil Konieczny
Date: Wed Mar 07 2018 - 05:22:34 EST
On 06.03.2018 19:04, Tom Lendacky wrote:
> On 3/6/2018 5:45 AM, Kamil Konieczny wrote:
>> Prevent improper use of req->digest field in ahash update, init, export and
>
> Shouldn't that be req->result (here and below)?
Yes, it should, I will send version 2 soon,
thank you.
Best regards,
Kamil Konieczny
>> import functions in drivers code. A driver should use ahash request context
>> if it needs to save internal state.
>>
>> Signed-off-by: Kamil Konieczny <k.konieczny@xxxxxxxxxxxxxxxxxxx>
>> ---
>> include/crypto/hash.h | 11 +++++++----
>> 1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/include/crypto/hash.h b/include/crypto/hash.h
>> index 2d1849dffb80..e97c2e662d6a 100644
>> --- a/include/crypto/hash.h
>> +++ b/include/crypto/hash.h
>> @@ -74,7 +74,8 @@ struct ahash_request {
>> * @init: **[mandatory]** Initialize the transformation context. Intended only to initialize the
>> * state of the HASH transformation at the beginning. This shall fill in
>> * the internal structures used during the entire duration of the whole
>> - * transformation. No data processing happens at this point.
>> + * transformation. No data processing happens at this point. Driver code
>> + * implementation must not use req->digest.
>> * @update: **[mandatory]** Push a chunk of data into the driver for transformation. This
>> * function actually pushes blocks of data from upper layers into the
>> * driver, which then passes those to the hardware as seen fit. This
>> @@ -83,7 +84,8 @@ struct ahash_request {
>> * transformation. This function shall not modify the transformation
>> * context, as this function may be called in parallel with the same
>> * transformation object. Data processing can happen synchronously
>> - * [SHASH] or asynchronously [AHASH] at this point.
>> + * [SHASH] or asynchronously [AHASH] at this point. Driver must not use
>> + * req->digest.
>> * @final: **[mandatory]** Retrieve result from the driver. This function finalizes the
>> * transformation and retrieves the resulting hash from the driver and
>> * pushes it back to upper layers. No data processing happens at this
>> @@ -120,11 +122,12 @@ struct ahash_request {
>> * you want to save partial result of the transformation after
>> * processing certain amount of data and reload this partial result
>> * multiple times later on for multiple re-use. No data processing
>> - * happens at this point.
>> + * happens at this point. Driver must not use req->digest.
>> * @import: Import partial state of the transformation. This function loads the
>> * entire state of the ongoing transformation from a provided block of
>> * data so the transformation can continue from this point onward. No
>> - * data processing happens at this point.
>> + * data processing happens at this point. Driver must not use
>> + * req->digest.
>> * @halg: see struct hash_alg_common
>> */
>> struct ahash_alg {
>>
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