From: Xin Xiong <xiongx18@fudan.edu.cn>
To: Tudor Ambarus <tudor.ambarus@microchip.com>,
Miquel Raynal <miquel.raynal@bootlin.com>,
Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Nicolas Ferre <nicolas.ferre@microchip.com>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
Claudiu Beznea <claudiu.beznea@microchip.com>,
Boris Brezillon <bbrezillon@kernel.org>,
linux-mtd@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: yuanxzhang@fudan.edu.cn, Xin Xiong <xiongx18@fudan.edu.cn>,
Xiyu Yang <xiyuyang19@fudan.edu.cn>,
Xin Tan <tanxin.ctf@gmail.com>
Subject: [PATCH v4] mtd: rawnand: atmel: fix refcount issue in atmel_nand_controller_init
Date: Fri, 4 Mar 2022 16:53:32 +0800 [thread overview]
Message-ID: <20220304085330.3610-1-xiongx18@fudan.edu.cn> (raw)
The reference counting issue happens in several error handling paths
on a refcounted object "nc->dmac". In these paths, the function simply
returns the error code, forgetting to balance the reference count of
"nc->dmac", increased earlier by dma_request_channel(), which may
cause refcount leaks.
Fix it by decrementing the refcount of specific object in those error
paths.
Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
Co-developed-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Co-developed-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
---
V3 -> V4: Removed useless condition check
V2 -> V3: Removed redundant lines
V1 -> V2: Rewrited the error handling block
---
drivers/mtd/nand/raw/atmel/nand-controller.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
index f3276ee9e4fe..ddd93bc38ea6 100644
--- a/drivers/mtd/nand/raw/atmel/nand-controller.c
+++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
@@ -2060,13 +2060,15 @@ static int atmel_nand_controller_init(struct atmel_nand_controller *nc,
nc->mck = of_clk_get(dev->parent->of_node, 0);
if (IS_ERR(nc->mck)) {
dev_err(dev, "Failed to retrieve MCK clk\n");
- return PTR_ERR(nc->mck);
+ ret = PTR_ERR(nc->mck);
+ goto out_release_dma;
}
np = of_parse_phandle(dev->parent->of_node, "atmel,smc", 0);
if (!np) {
dev_err(dev, "Missing or invalid atmel,smc property\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto out_release_dma;
}
nc->smc = syscon_node_to_regmap(np);
@@ -2074,10 +2076,16 @@ static int atmel_nand_controller_init(struct atmel_nand_controller *nc,
if (IS_ERR(nc->smc)) {
ret = PTR_ERR(nc->smc);
dev_err(dev, "Could not get SMC regmap (err = %d)\n", ret);
- return ret;
+ goto out_release_dma;
}
return 0;
+
+out_release_dma:
+ if (nc->dmac)
+ dma_release_channel(nc->dmac);
+
+ return ret;
}
static int
--
2.25.1
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next reply other threads:[~2022-03-04 9:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-04 8:53 Xin Xiong [this message]
2022-03-09 15:08 ` [PATCH v4] mtd: rawnand: atmel: fix refcount issue in atmel_nand_controller_init Claudiu.Beznea
2022-03-14 16:00 ` Miquel Raynal
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