ASoC: codecs: wsa883x: Correct Soundwire ports mask

Device has up to WSA883X_MAX_SWR_PORTS number of ports and the array
assigned to prop.sink_dpn_prop has 0..WSA883X_MAX_SWR_PORTS-1 elements.
On the other hand, GENMASK(high, low) creates an inclusive mask between
<high, low>, so we need the mask from 0 up to WSA883X_MAX_SWR_PORTS-1.

Theoretically, too wide mask could cause an out of bounds read in
sdw_get_slave_dpn_prop() in stream.c, however only in the case of buggy
driver, e.g. adding incorrect number of ports via
sdw_stream_add_slave().

Fixes: 43b8c7dc85a1 ("ASoC: codecs: add wsa883x amplifier support")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20240726-asoc-wcd-wsa-swr-ports-genmask-v1-5-d4d7a8b56f05@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/wsa883x.c b/sound/soc/codecs/wsa883x.c
index d0ab4e2..3e4fdaa 100644 (file)
--- a/sound/soc/codecs/wsa883x.c
+++ b/sound/soc/codecs/wsa883x.c
@@ -1406,7 +1406,7 @@ static int wsa883x_probe(struct sdw_slave *pdev,
                                        WSA883X_MAX_SWR_PORTS))
                dev_dbg(dev, "Static Port mapping not specified\n");
 
-       pdev->prop.sink_ports = GENMASK(WSA883X_MAX_SWR_PORTS, 0);
+       pdev->prop.sink_ports = GENMASK(WSA883X_MAX_SWR_PORTS - 1, 0);
        pdev->prop.simple_clk_stop_capable = true;
        pdev->prop.sink_dpn_prop = wsa_sink_dpn_prop;
        pdev->prop.scp_int1_mask = SDW_SCP_INT1_BUS_CLASH | SDW_SCP_INT1_PARITY;