linux-kernel - Re: [PATCH] crypto: af_alg - add async support to algif

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: <56AA3B19.8080604@intel.com>
Date:	Thu, 28 Jan 2016 08:00:25 -0800
From:	Tadeusz Struk <tadeusz.struk@...el.com>
To:	Stephan Mueller <smueller@...onox.de>
Cc:	herbert@...dor.apana.org.au, linux-crypto@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] crypto: af_alg - add async support to algif_aead

Hi Stephan,
On 01/27/2016 10:26 PM, Stephan Mueller wrote:
>> +	for (i = 0; i < areq->tsgls; i++)
>> > +		put_page(sg_page(sg + i));
> Shouldn't here be the same logic as in put_sgl? I.e.
> 
>         for (i = 0; i < sgl->cur; i++) {
>                 if (!sg_page(sg + i))
>                         continue;
> 
>                 put_page(sg_page(sg + i));
>                 sg_assign_page(sg + i, NULL);
>         }
> 

Thanks for reviewing.
I don't think it is possible that there ever will be any gaps in the tsgl.
In fact if there is such a possibility then it is a serious problem, because
it would mean that we are sending NULL ptrs to the ciphers (see line 640):

	sg_mark_end(sgl->sg + sgl->cur - 1);
	aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->first_rsgl.sgl.sg,
			       used, ctx->iv);

I don't see any implementation checking for null in sgls. Most of them just do:

	for_each_sg(sgl, sg, nents, i)
		sg_virt(sg)...

So it would Oops there. I think this check in put_sgl is redundant.
Thanks,
-- 
TS