From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     ulf.hansson@linaro.org
Cc:     linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH] mmc: sh_mmcif: Check for null res pointer
Date:   Wed,  5 Jan 2022 17:41:04 +0800
Message-Id: <20220105094104.2457423-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

If there is no suitable resource, platform_get_resource() will return
NULL.
Therefore in order to avoid the dereference of the NULL pointer, it
should be better to check the 'res'.

Fixes: 27cbd7e815a8 ("mmc: sh_mmcif: rework dma channel handling")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
 drivers/mmc/host/sh_mmcif.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index e5e457037235..45dfa3b0be9c 100644
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -405,6 +405,9 @@ static int sh_mmcif_dma_slave_config(struct sh_mmcif_host *host,
 	struct dma_slave_config cfg = { 0, };
 
 	res = platform_get_resource(host->pd, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
 	cfg.direction = direction;
 
 	if (direction == DMA_DEV_TO_MEM) {
-- 
2.25.1