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 <[email protected]>
Signed-off-by: Xiyu Yang <[email protected]>
Signed-off-by: Xin Tan <[email protected]>
---
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
Hi Xin,
[email protected] wrote on Tue, 25 Jan 2022 20:31:56 +0800:
> 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.
You might want to split this into two commits.
>
> Fix it by adding specific error handling code in those error paths.
You need a Fixes tag here.
> Signed-off-by: Xin Xiong <[email protected]>
> Signed-off-by: Xiyu Yang <[email protected]>
> Signed-off-by: Xin Tan <[email protected]>
You can't do that. The patch is rather straightforward, so 3
authorship seem a little bit too much.
If someone suggested you a change, or sent you a proposal, you should
use a Suggested-by. If it was reported by a colleague, use Reported-by.
If it was co-developped, use the right tag and the right Signed-off-by
as documented in the submitted-process.rst file. If you picked the
patch from someone else, you must preserve the authorship and just add
your SoB.
> ---
> 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)) {
&& !IS_ERR...
> + dma_release_channel(nc->dmac);
> + nc->dmac = NULL;
> + }
> + }
> +
> + return ret;
> }
>
> static int
Thanks,
Miquèl