[PATCH v3 2/3] mtd: rawnand: jz4780: fix possible object reference leak

[Wen Yang <yellowriver2010@xxxxxxxxxxx>]

of_find_device_by_node() takes a reference to the struct device
when it finds a match via get_device, there is no need to call
get_device() twice.
We also should make sure to drop the reference to the device
taken by of_find_device_by_node() on driver unbind.

Fixes: ae02ab00aa3c ("mtd: nand: jz4780: driver for NAND devices on JZ4780 SoCs")
Signed-off-by: Wen Yang <yellowriver2010@xxxxxxxxxxx>
Suggested-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Acked-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Cc: Harvey Hunt <harveyhuntnexus@xxxxxxxxx>
Cc: Boris Brezillon <bbrezillon@xxxxxxxxxx>
Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Cc: Richard Weinberger <richard@xxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Brian Norris <computersforpeace@xxxxxxxxx>
Cc: Marek Vasut <marek.vasut@xxxxxxxxx>
Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
v3->v2: Avoid two times of calling grtform_get_drvdata()
v2->v1: Since there is the only one user, let's remove the err_put_device label.

 drivers/mtd/nand/raw/jz4780_bch.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/raw/jz4780_bch.c b/drivers/mtd/nand/raw/jz4780_bch.c
index 7201827..7aab851 100644
--- a/drivers/mtd/nand/raw/jz4780_bch.c
+++ b/drivers/mtd/nand/raw/jz4780_bch.c
@@ -281,12 +281,14 @@ static struct jz4780_bch *jz4780_bch_get(struct device_node *np)
 	struct jz4780_bch *bch;
 
 	pdev = of_find_device_by_node(np);
-	if (!pdev || !platform_get_drvdata(pdev))
+	if (!pdev)
 		return ERR_PTR(-EPROBE_DEFER);
-
-	get_device(&pdev->dev);
-
 	bch = platform_get_drvdata(pdev);
+	if (!bch) {
+		put_device(&pdev->dev);
+		return ERR_PTR(-EPROBE_DEFER);
+	}
+
 	clk_prepare_enable(bch->clk);
 
 	return bch;
-- 
2.7.4


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