From 11493f26856a6098de6fe2d93e9eefebca3e31d6 Mon Sep 17 00:00:00 2001
From: Wen Yang <yellowriver2010@hotmail.com>
Date: Thu, 7 Feb 2019 14:01:23 +0000
Subject: [PATCH] mtd: rawnand: jz4780: fix possible object reference leak

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@hotmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/raw/jz4780_bch.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/raw/jz4780_bch.c b/drivers/mtd/nand/raw/jz4780_bch.c
index 7201827809e9a..c5f74ed858626 100644
--- a/drivers/mtd/nand/raw/jz4780_bch.c
+++ b/drivers/mtd/nand/raw/jz4780_bch.c
@@ -281,12 +281,15 @@ 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;
-- 
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