Commit 2367e0ec authored by Krzysztof Kozlowski's avatar Krzysztof Kozlowski Committed by Vinod Koul
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soundwire: qcom: gracefully handle too many ports in DT 



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: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: default avatarKonrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230222144412.237832-2-krzysztof.kozlowski@linaro.org


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 208a03ee

drivers/soundwire/qcom.c

+3 −0
Original line number Diff line number Diff line
@@ -1218,6 +1218,9 @@ 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);