soundwire: qcom: gracefully handle too many ports in DT
authorKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Wed, 22 Feb 2023 14:44:12 +0000 (15:44 +0100)
committerVinod Koul <vkoul@kernel.org>
Wed, 12 Apr 2023 10:00:35 +0000 (15:30 +0530)
commit2367e0ecb498764e95cfda691ff0828f7d25f9a4
tree57e3c0fa3120a5763c10300deb5575375cdbf65e
parent208a03ee9db815f28059d3399ee31577aeba0dd7
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: 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.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
drivers/soundwire/qcom.c