[PATCH v4 03/16] spi: s3c64xx: avoid possible negative array index

[Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>]

The platform id is used as an index into the fifo_lvl_mask array.
Platforms can come with a negative device ID, PLATFORM_DEVID_NONE (-1),
thus we risked a negative array index. Catch such cases and fail to
probe.

Fixes: 2b90807549e5 ("spi: s3c64xx: add device tree support")
Reviewed-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx>
Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>
---
 drivers/spi/spi-s3c64xx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 2b5bb7604526..c3176a510643 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1189,6 +1189,9 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 					     "Failed to get alias id\n");
 		sdd->port_id = ret;
 	} else {
+		if (pdev->id < 0)
+			return dev_err_probe(&pdev->dev, -EINVAL,
+					     "Negative platform ID is not allowed\n");
 		sdd->port_id = pdev->id;
 	}
 
-- 
2.43.0.594.gd9cf4e227d-goog