[PATCH] spi: sh-msiof: Fix potential NULL dereference in sh_msiof_request_dma

[Zhang Qilong <zhangqilong3@xxxxxxxxxx>]

platform_get_resource() may return NULL, add proper check to
avoid potential NULL dereferencing.

Fixes: b0d0ce8b6b91a ("spi: sh-msiof: Add DMA support")
Signed-off-by: Zhang Qilong <zhangqilong3@xxxxxxxxxx>
---
 drivers/spi/spi-sh-msiof.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index d0012b30410c..9d2754cc72b4 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -1191,6 +1191,9 @@ static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
 	if (!res)
 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 
+	if (!res)
+		return -ENOENT;
+
 	ctlr = p->ctlr;
 	ctlr->dma_tx = sh_msiof_request_dma_chan(dev, DMA_MEM_TO_DEV,
 						 dma_tx_id, res->start + SITFDR);
-- 
2.17.1