[Sound-open-firmware] [PATCH] DMIC: Add robustness against erroneous configuration parameters

[Liam Girdwood]

On Tue, 2018-05-22 at 20:07 +0300, Seppo Ingalsuo wrote:
> This patch ensures that modes matching request returns immediately if
> the results length would exceed the allocated length. The caller function
> will issue an error in such case.
> 
> Also the possibility of using array pdm[] in the IPM helper function
> as uninitialized is avoided by initializing it with zeros.
> 
> Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo at linux.intel.com>
> ---
>  src/drivers/dmic.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/src/drivers/dmic.c b/src/drivers/dmic.c
> index 33783f8..5c8591c 100644
> --- a/src/drivers/dmic.c
> +++ b/src/drivers/dmic.c
> @@ -334,6 +334,11 @@ static void match_modes(struct matched_modes *c, struct
> decim_modes *a,
>  		return;
>  	}
>  
> +	/* Ensure that num_of_modes is sane. */
> +	if (a->num_of_modes > DMIC_MAX_MODES ||
> +		b->num_of_modes > DMIC_MAX_MODES)
> +		return;
> +
>  	/* Check for request only for FIFO A or B. In such case pass list for
>  	 * A or B as such.
>  	 */
> @@ -633,7 +638,7 @@ static int select_mode(struct dmic_configuration *cfg,
>  static inline void ipm_helper(int *ipm, int stereo[], int swap[],
>  	struct sof_ipc_dai_dmic_params *dmic)
>  {
> -	int pdm[DMIC_HW_CONTROLLERS];
> +	int pdm[DMIC_HW_CONTROLLERS] = {0};
>  	int cnt;
>  	int i;
>  

Applied.

Thanks

Liam