linux-kernel - Re: [PATCH 2/3] crypto: api - adjust meaning of CRYPTO_ALG_ALLOCATES

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230705201812.GB866@sol.localdomain>
Date:   Wed, 5 Jul 2023 13:18:12 -0700
From:   Eric Biggers <ebiggers@...nel.org>
To:     Giovanni Cabiddu <giovanni.cabiddu@...el.com>
Cc:     herbert@...dor.apana.org.au, agk@...hat.com, snitzer@...nel.org,
        linux-crypto@...r.kernel.org, dm-devel@...hat.com,
        linux-kernel@...r.kernel.org, qat-linux@...el.com,
        heinzm@...hat.com, meenakshi.aggarwal@....com,
        horia.geanta@....com, V.Sethi@....com, pankaj.gupta@....com,
        gaurav.jain@....com, davem@...emloft.net, iuliana.prodan@....com,
        Fiona Trahe <fiona.trahe@...el.com>
Subject: Re: [PATCH 2/3] crypto: api - adjust meaning of
 CRYPTO_ALG_ALLOCATES_MEMORY

On Wed, Jul 05, 2023 at 05:40:08PM +0100, Giovanni Cabiddu wrote:

> Algorithms that do not set this flag will guarantee

"will guarantee" => "guarantee"
 
> that memory is not allocated during request processing, except in
> the avoidable exception cases described below.

"avoidable exception cases" => "exception cases"

Whether they are avoidable depends on the user.

> * Users can request an algorithm with this flag unset if they can't handle
> * memory allocation failures or sleeping during request processing.

Why add the "sleeping during request processing" part?  Isn't that controlled on
a per-request basis by CRYPTO_TFM_REQ_MAY_SLEEP which is a separate thing?

> * They should also follow the constraints below.

"should" => "must"

> + *	- The input and output scatterlists must have no more than 4 entries.
> + *	  If the scatterlists contain more than 4 entries, the algorithm may
> + *	  allocate memory.

"If the scatterlists contains" => "If either scatterlist contains"

Otherwise it is unclear whether this is talking about the length of each
scatterlist individually, or the sum of their lengths.

- Eric