mtd: rawnand: atmel: fix refcount issue in atmel_nand_controller_init

[ Upstream commit fecbd4a317 ]

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: f88fc122cc ("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>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220304085330.3610-1-xiongx18@fudan.edu.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Xin Xiong 2022-03-04 16:53:32 +08:00 committed by Greg Kroah-Hartman
parent d29cda15ca
commit fe0e2ce5c8

View file

@ -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