[alsa-devel] [PATCH 2/2] ALSA: snd-usb: use strncpy() in mixer_quirks.c

[Takashi Iwai]

At Sun, 19 Oct 2014 09:11:26 +0200,
Daniel Mack wrote:
> 
> Out of principles, use strncpy() in favor of strcpy().
> That is, however, an insignificant detail here.
> 
> Signed-off-by: Daniel Mack <daniel at zonque.org>

Well, blindly doing this isn't optimal, IMO.
First off, strlcpy() is a better one.  And, in the code you patched,
we already know all strings to be passed.  That is, if anything is
over the buffer size, it's a clear bug.  This can be caught by static
analyzers, or put some debug codes (either for build time or compile
time) instead of silently trimming the string.


thanks,

Takashi

> ---
>  sound/usb/mixer_quirks.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c
> index f119a41..f406305 100644
> --- a/sound/usb/mixer_quirks.c
> +++ b/sound/usb/mixer_quirks.c
> @@ -446,8 +446,9 @@ static int snd_emu0204_ch_switch_info(struct snd_kcontrol *kcontrol,
>  	uinfo->value.enumerated.items = 2;
>  	if (uinfo->value.enumerated.item > 1)
>  		uinfo->value.enumerated.item = 1;
> -	strcpy(uinfo->value.enumerated.name,
> -		texts[uinfo->value.enumerated.item]);
> +	strncpy(uinfo->value.enumerated.name,
> +		texts[uinfo->value.enumerated.item],
> +		sizeof(uinfo->value.enumerated.name) - 1);
>  
>  	return 0;
>  }
> -- 
> 2.1.0
>