memory: jz4780_nemc: Fix potential NULL dereference in jz4780_nemc_probe()

[ Upstream commit 4bfa07300b9334b487ed4f3d4901c35ebb31b7ca ]

platform_get_resource() may fail and return NULL, so we should
better check it's return value to avoid a NULL pointer dereference
a bit later in the code.

This is detected by Coccinelle semantic patch.

Fixes: 911a88829725 ("memory: jz4780-nemc: driver for the NEMC on JZ4780 SoCs")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/1607070717-32880-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/memory/jz4780-nemc.c b/drivers/memory/jz4780-nemc.c
index 3ec5cb0..465ea92 100644 (file)
--- a/drivers/memory/jz4780-nemc.c
+++ b/drivers/memory/jz4780-nemc.c
@@ -291,6 +291,8 @@ static int jz4780_nemc_probe(struct platform_device *pdev)
        nemc->dev = dev;
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res)
+               return -EINVAL;
 
        /*
         * The driver currently only uses the registers up to offset