Device has up to WCD937X_MAX_TX_SWR_PORTS (or WCD937X_MAX_SWR_PORTS for sink) number of ports and the array assigned to prop.src_dpn_prop and prop.sink_dpn_prop has 0..WCD937X_MAX_TX_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 WCD937X_MAX_TX_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: c99a515ff153 ("ASoC: codecs: wcd937x-sdw: add SoundWire driver") Signed-off-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org
---
Not adding Cc-stable because I don't think the issue can lead to real out-of-bounds read. --- sound/soc/codecs/wcd937x-sdw.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/soc/codecs/wcd937x-sdw.c b/sound/soc/codecs/wcd937x-sdw.c index 3abc8041406a..0c33f7f3dc25 100644 --- a/sound/soc/codecs/wcd937x-sdw.c +++ b/sound/soc/codecs/wcd937x-sdw.c @@ -1049,7 +1049,7 @@ static int wcd9370_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(WCD937X_MAX_TX_SWR_PORTS, 0); + pdev->prop.source_ports = GENMASK(WCD937X_MAX_TX_SWR_PORTS - 1, 0); pdev->prop.src_dpn_prop = wcd937x_dpn_prop; wcd->ch_info = &wcd937x_sdw_tx_ch_info[0]; pdev->prop.wake_capable = true; @@ -1062,7 +1062,7 @@ static int wcd9370_probe(struct sdw_slave *pdev, /* Start in cache-only until device is enumerated */ regcache_cache_only(wcd->regmap, true); } else { - pdev->prop.sink_ports = GENMASK(WCD937X_MAX_SWR_PORTS, 0); + pdev->prop.sink_ports = GENMASK(WCD937X_MAX_SWR_PORTS - 1, 0); pdev->prop.sink_dpn_prop = wcd937x_dpn_prop; wcd->ch_info = &wcd937x_sdw_rx_ch_info[0]; }