2022-05-11 08:49:02

by Miaoqian Lin

Subject: [PATCH] ata: pata_octeon_cf: Fix refcount leak in octeon_cf_probe

of_find_device_by_node() takes reference, we should use put_device()
to release it when not need anymore.
Add missing put_device() in error path to avoid refcount
leak.

Fixes: 43f01da0f279 ("MIPS/OCTEON/ata: Convert pata_octeon_cf.c to use device tree.")
Signed-off-by: Miaoqian Lin <[email protected]>
---
drivers/ata/pata_octeon_cf.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/ata/pata_octeon_cf.c b/drivers/ata/pata_octeon_cf.c
index 6b5ed3046b44..65688459acf1 100644
--- a/drivers/ata/pata_octeon_cf.c
+++ b/drivers/ata/pata_octeon_cf.c
@@ -857,12 +857,14 @@ static int octeon_cf_probe(struct platform_device *pdev)
res_dma = platform_get_resource(dma_dev, IORESOURCE_MEM, 0);
if (!res_dma) {
of_node_put(dma_node);
+ put_device(&dma_dev->dev);
return -EINVAL;
}
cf_port->dma_base = (u64)devm_ioremap(&pdev->dev, res_dma->start,
resource_size(res_dma));
if (!cf_port->dma_base) {
of_node_put(dma_node);
+ put_device(&dma_dev->dev);
return -EINVAL;
}

--
2.25.1

2022-05-11 10:43:29

by Damien Le Moal

Subject: Re: [PATCH] ata: pata_octeon_cf: Fix refcount leak in octeon_cf_probe

On 2022/05/11 8:27, Miaoqian Lin wrote:
> of_find_device_by_node() takes reference, we should use put_device()
> to release it when not need anymore.
> Add missing put_device() in error path to avoid refcount
> leak.
>
> Fixes: 43f01da0f279 ("MIPS/OCTEON/ata: Convert pata_octeon_cf.c to use device tree.")
> Signed-off-by: Miaoqian Lin <[email protected]>
> ---
> drivers/ata/pata_octeon_cf.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/ata/pata_octeon_cf.c b/drivers/ata/pata_octeon_cf.c
> index 6b5ed3046b44..65688459acf1 100644
> --- a/drivers/ata/pata_octeon_cf.c
> +++ b/drivers/ata/pata_octeon_cf.c
> @@ -857,12 +857,14 @@ static int octeon_cf_probe(struct platform_device *pdev)
> res_dma = platform_get_resource(dma_dev, IORESOURCE_MEM, 0);
> if (!res_dma) {
> of_node_put(dma_node);
> + put_device(&dma_dev->dev);
> return -EINVAL;
> }
> cf_port->dma_base = (u64)devm_ioremap(&pdev->dev, res_dma->start,
> resource_size(res_dma));
> if (!cf_port->dma_base) {
> of_node_put(dma_node);
> + put_device(&dma_dev->dev);
> return -EINVAL;
> }
>

The extra reference should also be dropped at the end of the "if (dma_node)"
too, no ? Otherwise, early returns due to errors after that "if (dma_node)" will
also leak the extra ref.

Note that looking around at places where of_find_device_by_node() is being used,
very few users call put_device()... Looks like there are lots of device ref
leaks with that.

--
Damien Le Moal
Western Digital Research

2022-05-11 12:01:00

by Sergey Shtylyov

Subject: Re: [PATCH] ata: pata_octeon_cf: Fix refcount leak in octeon_cf_probe

Hello!

On 5/11/22 9:27 AM, Miaoqian Lin wrote:

> of_find_device_by_node() takes reference, we should use put_device()
> to release it when not need anymore.
> Add missing put_device() in error path to avoid refcount
> leak.
>
> Fixes: 43f01da0f279 ("MIPS/OCTEON/ata: Convert pata_octeon_cf.c to use device tree.")
> Signed-off-by: Miaoqian Lin <[email protected]>
> ---
> drivers/ata/pata_octeon_cf.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/ata/pata_octeon_cf.c b/drivers/ata/pata_octeon_cf.c
> index 6b5ed3046b44..65688459acf1 100644
> --- a/drivers/ata/pata_octeon_cf.c
> +++ b/drivers/ata/pata_octeon_cf.c
> @@ -857,12 +857,14 @@ static int octeon_cf_probe(struct platform_device *pdev)
> res_dma = platform_get_resource(dma_dev, IORESOURCE_MEM, 0);
> if (!res_dma) {
> of_node_put(dma_node);
> + put_device(&dma_dev->dev);
> return -EINVAL;
> }
> cf_port->dma_base = (u64)devm_ioremap(&pdev->dev, res_dma->start,
> resource_size(res_dma));
> if (!cf_port->dma_base) {
> of_node_put(dma_node);
> + put_device(&dma_dev->dev);
> return -EINVAL;
> }
>

It seems you forgot to call put_device() at the end of the enclosing *if*, where of_node_put()
is also called...

MBR, Sergey