Messages in this thread Patch in this message | | | From | Xin Xiong <> | Subject | [PATCH] mtd: rawnand: atmel: fix refcount leaks in atmel_nand_controller_init | Date | Tue, 25 Jan 2022 20:31:56 +0800 |
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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 increased earlier by dma_request_channel(), which may cause refcount leaks. What's more, the "nc->mck" object also needs to be handled correctly.
Fix it by adding specific error handling code in those error paths.
Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn> Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> --- drivers/mtd/nand/raw/atmel/nand-controller.c | 22 +++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c index f3276ee9e..b3801ebd2 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_put_clk; } nc->smc = syscon_node_to_regmap(np); @@ -2074,10 +2076,24 @@ 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_put_clk; } return 0; + +out_put_clk: + clk_put(nc->mck); + nc->mck = NULL; + +out_release_dma: + if (nc->caps->has_dma && !atmel_nand_avoid_dma) { + if (!IS_ERR_OR_NULL(nc->dmac)) { + dma_release_channel(nc->dmac); + nc->dmac = NULL; + } + } + + return ret; } static int -- 2.25.1
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