[alsa-devel] [PATCH 2/2] ASoC: fsl: use strncpy() to prevent copying of over-long names

[Takashi Iwai]

At Mon, 20 Oct 2014 07:55:22 +0200,
Mike Looijmans wrote:
> 
> This hardly improves matters. When the source string is larger than the 
> buffer, the destination may not be nul-terminated.
> Also, strncpy ALWAYS writes the full buffer so it may be wasting cycles when 
> the destination buffer is large.

Indeed, strncpy() should be avoided.

> I'm sure the kernel offers a better alternative. Even "snprintf" is a better 
> alternative.

strlcpy() is the best choice.


Takashi


> 
> Mike.
> 
> 
> On 10/19/2014 09:07 AM, Daniel Mack wrote:
> > Use strncpy() instead of strcpy(). That's not a security issue, as the
> > source buffer is taken from DT nodes, but we should still enforce bound
> > checks. Spotted by Coverity.
> >
> > Signed-off-by: Daniel Mack <daniel at zonque.org>
> > ---
> >   sound/soc/fsl/fsl_asrc.c | 2 +-
> >   sound/soc/fsl/fsl_esai.c | 2 +-
> >   2 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/sound/soc/fsl/fsl_asrc.c b/sound/soc/fsl/fsl_asrc.c
> > index 8221104..dd00b9d 100644
> > --- a/sound/soc/fsl/fsl_asrc.c
> > +++ b/sound/soc/fsl/fsl_asrc.c
> > @@ -792,7 +792,7 @@ static int fsl_asrc_probe(struct platform_device *pdev)
> >   		return -ENOMEM;
> >
> >   	asrc_priv->pdev = pdev;
> > -	strcpy(asrc_priv->name, np->name);
> > +	strncpy(asrc_priv->name, np->name, sizeof(asrc_priv->name) - 1);
> >
> >   	/* Get the addresses and IRQ */
> >   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c
> > index a3b29ed..fda1d46 100644
> > --- a/sound/soc/fsl/fsl_esai.c
> > +++ b/sound/soc/fsl/fsl_esai.c
> > @@ -729,7 +729,7 @@ static int fsl_esai_probe(struct platform_device *pdev)
> >   		return -ENOMEM;
> >
> >   	esai_priv->pdev = pdev;
> > -	strcpy(esai_priv->name, np->name);
> > +	strncpy(esai_priv->name, np->name, sizeof(esai_priv->name) - 1);
> >
> >   	if (of_property_read_bool(np, "big-endian"))
> >   		fsl_esai_regmap_config.val_format_endian = REGMAP_ENDIAN_BIG;
> >
> 
> 
> 
> Met vriendelijke groet / kind regards,
> 
> Mike Looijmans
> 
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