[PATCH 6/6] ASoC: codecs: wsa884x: Correct Soundwire ports mask

From: Krzysztof Kozlowski
Date: Fri Jul 26 2024 - 10:12:32 EST


Device has up to WSA884X_MAX_SWR_PORTS number of ports and the array
assigned to prop.sink_dpn_prop has 0..WSA884X_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 WSA884X_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: aa21a7d4f68a ("ASoC: codecs: wsa884x: Add WSA884x family of speakers")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>

---

Not adding Cc-stable because I don't think the issue can lead to real
out-of-bounds read.
---
sound/soc/codecs/wsa884x.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/codecs/wsa884x.c b/sound/soc/codecs/wsa884x.c
index d17ae17b2938..89eb5e03a617 100644
--- a/sound/soc/codecs/wsa884x.c
+++ b/sound/soc/codecs/wsa884x.c
@@ -1895,7 +1895,7 @@ static int wsa884x_probe(struct sdw_slave *pdev,
WSA884X_MAX_SWR_PORTS))
dev_dbg(dev, "Static Port mapping not specified\n");

- pdev->prop.sink_ports = GENMASK(WSA884X_MAX_SWR_PORTS, 0);
+ pdev->prop.sink_ports = GENMASK(WSA884X_MAX_SWR_PORTS - 1, 0);
pdev->prop.simple_clk_stop_capable = true;
pdev->prop.sink_dpn_prop = wsa884x_sink_dpn_prop;
pdev->prop.scp_int1_mask = SDW_SCP_INT1_BUS_CLASH | SDW_SCP_INT1_PARITY;

--
2.43.0