tty: serial: 8250_mtk: Fix potential NULL pointer dereference

GustavoARSilva · gregkh · commit 1575c083a78c · 2019-01-30T09:35:46.000+01:00
There is a potential NULL pointer dereference in case devm_kzalloc() fails and returns NULL. Fix this by adding a NULL check on data->dma This bug was detected with the help of Coccinelle. Fixes: 85b5c1d ("serial: 8250-mtk: add uart DMA support") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
@@ -357,6 +357,9 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
 	if (dmacnt == 2) {
 		data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma),
 					 GFP_KERNEL);
+		if (!data->dma)
+			return -ENOMEM;
+
 		data->dma->fn = mtk8250_dma_filter;
 		data->dma->rx_size = MTK_UART_RX_SIZE;
 		data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER;
