[Freedreno] [PATCH] drm/msm: Use scnprintf() for avoiding potential buffer overflow

[Jordan Crouse]

On Wed, Mar 11, 2020 at 08:34:10AM +0100, Takashi Iwai wrote:
> Since snprintf() returns the would-be-output size instead of the
> actual output size, the succeeding calls may go beyond the given
> buffer limit.  Fix it by replacing with scnprintf().

How embarrassing. I'm usually the guy singing the praises of scnprintf().
Thanks for the fix.

Reviewed-by: Jordan Crouse <jcrouse at codeaurora.org>

> Signed-off-by: Takashi Iwai <tiwai at suse.de>
> ---
>  drivers/gpu/drm/msm/adreno/adreno_gpu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> index 7fd29829b2fa..1d5c43c22269 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> @@ -673,7 +673,7 @@ static char *adreno_gpu_ascii85_encode(u32 *src, size_t len)
>  		return NULL;
>  
>  	for (i = 0; i < l; i++)
> -		buf_itr += snprintf(buf + buf_itr, buffer_size - buf_itr, "%s",
> +		buf_itr += scnprintf(buf + buf_itr, buffer_size - buf_itr, "%s",
>  				ascii85_encode(src[i], out));
>  
>  	return buf;
> -- 
> 2.16.4
> 

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