2022-05-23 11:13:28

by CGEL

Subject: [PATCH] firmware: arm_scmi: Avoid leak OF node on error

From: Minghao Chi <[email protected]>

The OF node should be put before returning error in smc_chan_available(),
otherwise node's refcount will be leaked.

Reported-by: Zeal Robot <[email protected]>
Signed-off-by: Minghao Chi <[email protected]>
---
drivers/firmware/arm_scmi/smc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
index 745acfdd0b3d..43018be70edc 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -55,10 +55,10 @@ static irqreturn_t smc_msg_done_isr(int irq, void *data)
static bool smc_chan_available(struct device *dev, int idx)
{
struct device_node *np = of_parse_phandle(dev->of_node, "shmem", 0);
+ of_node_put(np);
if (!np)
return false;

- of_node_put(np);
return true;
}

--
2.25.1

2022-05-23 11:54:17

by Johan Hovold

Subject: Re: [PATCH] firmware: arm_scmi: Avoid leak OF node on error

On Mon, May 23, 2022 at 11:11:16AM +0000, [email protected] wrote:
> From: Minghao Chi <[email protected]>
>
> The OF node should be put before returning error in smc_chan_available(),
> otherwise node's refcount will be leaked.
>
> Reported-by: Zeal Robot <[email protected]>
> Signed-off-by: Minghao Chi <[email protected]>
> ---
> drivers/firmware/arm_scmi/smc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
> index 745acfdd0b3d..43018be70edc 100644
> --- a/drivers/firmware/arm_scmi/smc.c
> +++ b/drivers/firmware/arm_scmi/smc.c
> @@ -55,10 +55,10 @@ static irqreturn_t smc_msg_done_isr(int irq, void *data)
> static bool smc_chan_available(struct device *dev, int idx)
> {
> struct device_node *np = of_parse_phandle(dev->of_node, "shmem", 0);
> + of_node_put(np);
> if (!np)
> return false;
>
> - of_node_put(np);
> return true;
> }

NAK

2022-05-23 13:29:31

by Sudeep Holla

Subject: Re: [PATCH] firmware: arm_scmi: Avoid leak OF node on error

On Mon, May 23, 2022 at 11:11:16AM +0000, [email protected] wrote:
> From: Minghao Chi <[email protected]>
>
> The OF node should be put before returning error in smc_chan_available(),
> otherwise node's refcount will be leaked.
>
> Reported-by: Zeal Robot <[email protected]>
> Signed-off-by: Minghao Chi <[email protected]>
> ---
> drivers/firmware/arm_scmi/smc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
> index 745acfdd0b3d..43018be70edc 100644
> --- a/drivers/firmware/arm_scmi/smc.c
> +++ b/drivers/firmware/arm_scmi/smc.c
> @@ -55,10 +55,10 @@ static irqreturn_t smc_msg_done_isr(int irq, void *data)
> static bool smc_chan_available(struct device *dev, int idx)
> {
> struct device_node *np = of_parse_phandle(dev->of_node, "shmem", 0);
> + of_node_put(np);

While this may work as of_node_put handles NULL as argument, what is the
point of unnecessary of_node_put(NULL) here ?

--
Regards,
Sudeep