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From:   Mattijs Korpershoek <mkorpershoek@baylibre.com>
To:     Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Matthias Brugger <matthias.bgg@gmail.com>
Cc:     fparent@baylibre.com,
        Mattijs Korpershoek <mkorpershoek@baylibre.com>,
        linux-input@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/7] Input: mtk-pmic-keys - check for NULL on of_match_device()
Date:   Wed, 28 Apr 2021 18:42:13 +0200
Message-Id: <20210428164219.1115537-2-mkorpershoek@baylibre.com>
In-Reply-To: <20210428164219.1115537-1-mkorpershoek@baylibre.com>
References: <20210428164219.1115537-1-mkorpershoek@baylibre.com>
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mtk-pmic-keys being a child device of mt6397, it will always get probed
when mt6397_probe() is called.

This also happens when we have no device tree node matching
mediatek,mt6397-keys.

In that case, the mfd core warns us:

  [    0.352175] mtk-pmic-keys: Failed to locate of_node [id: -1]

Check return value from call to of_match_device()
in order to prevent a NULL pointer dereference.

In case of NULL print error message and return -ENODEV

Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
 drivers/input/keyboard/mtk-pmic-keys.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/input/keyboard/mtk-pmic-keys.c b/drivers/input/keyboard/mtk-pmic-keys.c
index 62391d6c7da6..12c449eed026 100644
--- a/drivers/input/keyboard/mtk-pmic-keys.c
+++ b/drivers/input/keyboard/mtk-pmic-keys.c
@@ -247,6 +247,9 @@ static int mtk_pmic_keys_probe(struct platform_device *pdev)
 	const struct of_device_id *of_id =
 		of_match_device(of_mtk_pmic_keys_match_tbl, &pdev->dev);
 
+	if (!of_id)
+		return -ENODEV;
+
 	keys = devm_kzalloc(&pdev->dev, sizeof(*keys), GFP_KERNEL);
 	if (!keys)
 		return -ENOMEM;
-- 
2.27.0