Re: [PATCH] mac80211: aes_ccm: move struct aead_req off the stack

[Ard Biesheuvel]

> On 14 Oct 2016, at 14:46, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote:
> 
> 
>> 
>> Is the aad[] actually reused? I would assume it only affects the mac
>> on encryption, and the verification on decryption but I don't think
>> we actually need it back from the crypto routines.
> 
> I don't think it's reused.
> 
>> Exactly what you said above :-) My patch only touches CCM but as you
>> said,
>> 
>> """
>> 'Also there's B_0/J_0 for CCM/GCM, and the 'zero' thing that GMAC
>> has.
>> """
> 
> Ah, but we can/should do the same for the others, no?
> 

Yes, but then we end up kmalloc/kfreeing chunks of 16 bytes, which is actually another problem.

I still think we are not violating the api by putting aead_req on the stack (but herbert should confirm). The aad[] issue does violate the api, so it deserves a separate fix imo