ASoC: codecs: wcd938x-sdw: Correct Soundwire ports mask

[ Upstream commit 3f6fb03dae9c7dfba7670858d29e03c8faaa89fe ]

Device has up to WCD938X_MAX_SWR_PORTS number of ports and the array
assigned to prop.src_dpn_prop and prop.sink_dpn_prop has
0..WCD938X_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 WCD938X_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: 16572522aece ("ASoC: codecs: wcd938x-sdw: add SoundWire driver")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20240726-asoc-wcd-wsa-swr-ports-genmask-v1-2-d4d7a8b56f05@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/sound/soc/codecs/wcd938x-sdw.c b/sound/soc/codecs/wcd938x-sdw.c
index a1f04010da95f60278071292254d4f3489a40bba..132c1d24f8f6e788788e6546fa1792ed4da83f7a 100644 (file)
--- a/sound/soc/codecs/wcd938x-sdw.c
+++ b/sound/soc/codecs/wcd938x-sdw.c
@@ -1252,12 +1252,12 @@ static int wcd9380_probe(struct sdw_slave *pdev,
        pdev->prop.lane_control_support = true;
        pdev->prop.simple_clk_stop_capable = true;
        if (wcd->is_tx) {
-               pdev->prop.source_ports = GENMASK(WCD938X_MAX_SWR_PORTS, 0);
+               pdev->prop.source_ports = GENMASK(WCD938X_MAX_SWR_PORTS - 1, 0);
                pdev->prop.src_dpn_prop = wcd938x_dpn_prop;
                wcd->ch_info = &wcd938x_sdw_tx_ch_info[0];
                pdev->prop.wake_capable = true;
        } else {
-               pdev->prop.sink_ports = GENMASK(WCD938X_MAX_SWR_PORTS, 0);
+               pdev->prop.sink_ports = GENMASK(WCD938X_MAX_SWR_PORTS - 1, 0);
                pdev->prop.sink_dpn_prop = wcd938x_dpn_prop;
                wcd->ch_info = &wcd938x_sdw_rx_ch_info[0];
        }