From 2367e0ecb498764e95cfda691ff0828f7d25f9a4 Mon Sep 17 00:00:00 2001

From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Date: Wed, 22 Feb 2023 15:44:12 +0100

Subject: [PATCH] soundwire: qcom: gracefully handle too many ports in DT

Git-commit: 2367e0ecb498764e95cfda691ff0828f7d25f9a4

Patch-mainline: v6.4-rc1

References: git-fixes

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>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 drivers/soundwire/qcom.c | 3 +++

 1 file changed, 3 insertions(+)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c

index 79bebcecde6d..c296e0bf897b 100644

--- a/drivers/soundwire/qcom.c

+++ b/drivers/soundwire/qcom.c

@@ -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);

-- 

2.35.3