linux-kernel - Re: [alsa-devel] [PATCH 1/7 v2] dmaengine: add a simple dma library

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: <Pine.LNX.4.64.1201262206530.10057@axis700.grange>
Date:	Thu, 26 Jan 2012 22:07:50 +0100 (CET)
From:	Guennadi Liakhovetski <g.liakhovetski@....de>
To:	Sascha Hauer <s.hauer@...gutronix.de>
cc:	linux-kernel@...r.kernel.org, alsa-devel@...a-project.org,
	linux-sh@...r.kernel.org, Vinod Koul <vinod.koul@...el.com>,
	Magnus Damm <magnus.damm@...il.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>,
	linux-mmc@...r.kernel.org, Paul Mundt <lethal@...ux-sh.org>,
	linux-serial@...r.kernel.org
Subject: Re: [alsa-devel] [PATCH 1/7 v2] dmaengine: add a simple dma library

Hi Sascha

On Thu, 26 Jan 2012, Sascha Hauer wrote:

> Hi Guennadi,
> 
> On Thu, Jan 26, 2012 at 03:56:18PM +0100, Guennadi Liakhovetski wrote:
> > This patch adds a library of functions, helping to implement dmaengine
> > drivers for hardware, unable to handle scatter-gather lists natively.
> > The first version of this driver only supports memcpy and slave DMA
> > operation.
> > 
> > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@....de>
> > ---
> > 
> 
> [...]
> 
> > +
> > +/*
> > + * For slave DMA we assume, that there is a finite number of DMA slaves in the
> > + * system, and that each such slave can only use a finite number of channels.
> > + * We use slave channel IDs to make sure, that no such slave channel ID is
> > + * allocated more than once.
> > + */
> > +static unsigned int slave_num = 256;
> > +module_param(slave_num, uint, 0444);
> > +
> > +/* A bitmask with slave_num bits */
> > +static unsigned long *simple_slave_used;
> 
> You never check that the slave ids passed into this code are
> within the range of slave_num. Given that this is a user changeable
> value this is a bit flawy.

Right, never trust the user;-) I'll fix that.

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/