From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     davem@davemloft.net
Cc:     linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH] ide: Check for null pointer after calling devm_ioremap
Date:   Fri,  7 Jan 2022 11:17:33 +0800
Message-Id: <20220107031733.3588290-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

As the possible failure of the devres_alloc(), the devm_ioremap() and
devm_ioport_map() may return NULL pointer.
And then, the 'base' and 'alt_base' is used in plat_ide_setup_ports().
Therefore, it should be better to add the check in order to avoid the
dereference of the NULL pointer.

Fixes: 2bfba3c444fe ("ide: remove useless subdirs from drivers/ide/")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
 drivers/ide/ide_platform.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/ide/ide_platform.c b/drivers/ide/ide_platform.c
index 91639fd6c276..8c6e1af7b6eb 100644
--- a/drivers/ide/ide_platform.c
+++ b/drivers/ide/ide_platform.c
@@ -85,6 +85,10 @@ static int plat_ide_probe(struct platform_device *pdev)
 		alt_base = devm_ioport_map(&pdev->dev,
 			res_alt->start, resource_size(res_alt));
 	}
+	if (!base || !alt_base) {
+		ret = -ENOMEM;
+		goto out;
+	}
 
 	memset(&hw, 0, sizeof(hw));
 	plat_ide_setup_ports(&hw, base, alt_base, pdata, res_irq->start);
-- 
2.25.1