From: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org

[ Upstream commit 2367e0ecb498764e95cfda691ff0828f7d25f9a4 ]

There are two issues related to the number of ports coming from Devicetree when exceeding in total QCOM_SDW_MAX_PORTS. Both lead to incorrect memory accesses: 1. With DTS having too big value of input or output ports, the driver, when copying port parameters from local/stack arrays into 'pconfig' array in 'struct qcom_swrm_ctrl', will iterate over their sizes.

2. If DTS also has too many parameters for these ports (e.g. qcom,ports-sinterval-low), the driver will overflow buffers on the stack when reading these properties from DTS.

Add a sanity check so incorrect DTS will not cause kernel memory corruption.

Signed-off-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org Reviewed-by: Srinivas Kandagatla srinivas.kandagatla@linaro.org Reviewed-by: Konrad Dybcio konrad.dybcio@linaro.org Link: https://lore.kernel.org/r/20230222144412.237832-2-krzysztof.kozlowski@linaro... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/soundwire/qcom.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c index 500035a1fd460..e76d4cee5e7f4 100644 --- a/drivers/soundwire/qcom.c +++ b/drivers/soundwire/qcom.c @@ -1142,6 +1142,9 @@ static int qcom_swrm_get_port_config(struct qcom_swrm_ctrl *ctrl) ctrl->num_dout_ports = val;

nports = ctrl->num_dout_ports + ctrl->num_din_ports; + if (nports > QCOM_SDW_MAX_PORTS) + return -EINVAL; + /* Valid port numbers are from 1-14, so mask out port 0 explicitly */ set_bit(0, &ctrl->dout_port_mask); set_bit(0, &ctrl->din_port_mask);