On 22/02/2023 14:44, Krzysztof Kozlowski wrote:
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@xxxxxxxxxx>
---
Thanks Krzysztof, it make sense.
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
--srini
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);
