Re: [PATCH] soundwire: qcom: fix storing port config out-of-bounds

[Konrad Dybcio]

On 1.06.2023 12:25, Krzysztof Kozlowski wrote:
> The 'qcom_swrm_ctrl->pconfig' has size of QCOM_SDW_MAX_PORTS (14),
> however we index it starting from 1, not 0, to match real port numbers.
> This can lead to writing port config past 'pconfig' bounds and
> overwriting next member of 'qcom_swrm_ctrl' struct.  Reported also by
> smatch:
> 
>   drivers/soundwire/qcom.c:1269 qcom_swrm_get_port_config() error: buffer overflow 'ctrl->pconfig' 14 <= 14
> 
> Fixes: 9916c02ccd74 ("soundwire: qcom: cleanup internal port config indexing")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Reported-by: Dan Carpenter <error27@xxxxxxxxx>
> Link: https://lore.kernel.org/r/202305201301.sCJ8UDKV-lkp@xxxxxxxxx/
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>

Konrad
>  drivers/soundwire/qcom.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
> index 7cb1b7eba814..88a772075907 100644
> --- a/drivers/soundwire/qcom.c
> +++ b/drivers/soundwire/qcom.c
> @@ -202,7 +202,8 @@ struct qcom_swrm_ctrl {
>  	u32 intr_mask;
>  	u8 rcmd_id;
>  	u8 wcmd_id;
> -	struct qcom_swrm_port_config pconfig[QCOM_SDW_MAX_PORTS];
> +	/* Port numbers are 1 - 14 */
> +	struct qcom_swrm_port_config pconfig[QCOM_SDW_MAX_PORTS + 1];
>  	struct sdw_stream_runtime *sruntime[SWRM_MAX_DAIS];
>  	enum sdw_slave_status status[SDW_MAX_DEVICES + 1];
>  	int (*reg_read)(struct qcom_swrm_ctrl *ctrl, int reg, u32 *val);