[PATCH net] phy: fix error case of phy_led_triggers_(un)register

[PATCH net] phy: fix error case of phy_led_triggers_(un)register

[Woojung.Huh]

From: Woojung Huh <woojung.huh@microchip.com>

When phy_init_hw() fails at phy_attach_direct();
- phy_detach() calls phy_led_triggers_unregister() without 
  previous call of phy_led_triggers_register().
- still call phy_led_triggers_register() and cause memory leak.

Signed-off-by: Woojung Huh <woojung.huh@microchip.com>
---
 drivers/net/phy/phy_device.c       | 6 +++---
 drivers/net/phy/phy_led_triggers.c | 3 +++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 9e8f048..094a959 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -915,10 +915,10 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
 	err = phy_init_hw(phydev);
 	if (err)
 		phy_detach(phydev);
-	else
+	else {
 		phy_resume(phydev);
-
-	phy_led_triggers_register(phydev);
+		phy_led_triggers_register(phydev);
+	}
 
 	return err;
 
diff --git a/drivers/net/phy/phy_led_triggers.c b/drivers/net/phy/phy_led_triggers.c
index cda600a..3b0b726 100644
--- a/drivers/net/phy/phy_led_triggers.c
+++ b/drivers/net/phy/phy_led_triggers.c
@@ -128,6 +128,9 @@ void phy_led_triggers_unregister(struct phy_device *phy)
 {
 	int i;
 
+	if (!phy->phy_num_led_triggers)
+		return;
+
 	for (i = 0; i < phy->phy_num_led_triggers; i++)
 		phy_led_trigger_unregister(&phy->phy_led_triggers[i]);
 
-- 
2.7.4

Re: [PATCH net] phy: fix error case of phy_led_triggers_(un)register

[Sergei Shtylyov]

Hello.

On 11/24/2016 12:39 AM, Woojung.Huh@microchip.com wrote:

> From: Woojung Huh <woojung.huh@microchip.com>
>
> When phy_init_hw() fails at phy_attach_direct();
> - phy_detach() calls phy_led_triggers_unregister() without
>   previous call of phy_led_triggers_register().
> - still call phy_led_triggers_register() and cause memory leak.
>
> Signed-off-by: Woojung Huh <woojung.huh@microchip.com>
> ---
>  drivers/net/phy/phy_device.c       | 6 +++---
>  drivers/net/phy/phy_led_triggers.c | 3 +++
>  2 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 9e8f048..094a959 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -915,10 +915,10 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
>  	err = phy_init_hw(phydev);
>  	if (err)
>  		phy_detach(phydev);
> -	else
> +	else {

    CodingStyle: all *if* branches should have {} if at least one has {}.

>  		phy_resume(phydev);
> -
> -	phy_led_triggers_register(phydev);
> +		phy_led_triggers_register(phydev);
> +	}
>
>  	return err;
>
[...]

MBR, Sergei

Re: [PATCH net] phy: fix error case of phy_led_triggers_(un)register

[Andrew Lunn]

On Wed, Nov 23, 2016 at 09:39:37PM +0000, Woojung.Huh@microchip.com wrote:
> From: Woojung Huh <woojung.huh@microchip.com>
> 
> When phy_init_hw() fails at phy_attach_direct();
> - phy_detach() calls phy_led_triggers_unregister() without 
>   previous call of phy_led_triggers_register().
> - still call phy_led_triggers_register() and cause memory leak.
> 
> Signed-off-by: Woojung Huh <woojung.huh@microchip.com>
> ---
>  drivers/net/phy/phy_device.c       | 6 +++---
>  drivers/net/phy/phy_led_triggers.c | 3 +++
>  2 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 9e8f048..094a959 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -915,10 +915,10 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
>  	err = phy_init_hw(phydev);
>  	if (err)
>  		phy_detach(phydev);
> -	else
> +	else {
>  		phy_resume(phydev);
> -
> -	phy_led_triggers_register(phydev);
> +		phy_led_triggers_register(phydev);
> +	}

Hi Woojung

The code layout is rather unusual, putting the success case inside the
else {}. It would be better to do a goto out: on error, and detach the
phy there.

>  
>  	return err;
>  
> diff --git a/drivers/net/phy/phy_led_triggers.c b/drivers/net/phy/phy_led_triggers.c
> index cda600a..3b0b726 100644
> --- a/drivers/net/phy/phy_led_triggers.c
> +++ b/drivers/net/phy/phy_led_triggers.c
> @@ -128,6 +128,9 @@ void phy_led_triggers_unregister(struct phy_device *phy)
>  {
>  	int i;
>  
> +	if (!phy->phy_num_led_triggers)
> +		return;
> +
>  	for (i = 0; i < phy->phy_num_led_triggers; i++)
>  		phy_led_trigger_unregister(&phy->phy_led_triggers[i]);

And this seems to be the wrong fix. The point of devm_kzalloc() is
that you don't need to free it, it will happen automatically. So why
not just remove the devm_kfree(&phy->mdio.dev, phy->phy_led_triggers).

    Andrew

Re: [PATCH net] phy: fix error case of phy_led_triggers_(un)register

[Florian Fainelli]

Le 23/11/2016 à 13:39, Woojung.Huh@microchip.com a écrit :
> From: Woojung Huh <woojung.huh@microchip.com>
> 
> When phy_init_hw() fails at phy_attach_direct();
> - phy_detach() calls phy_led_triggers_unregister() without 
>   previous call of phy_led_triggers_register().
> - still call phy_led_triggers_register() and cause memory leak.
> 
> Signed-off-by: Woojung Huh <woojung.huh@microchip.com>

Since you probably have to resubmit this, can you also add a Fixes tag:

Fixes: 2e0bc452f472 ("net: phy: leds: add support for led triggers on
phy link state change")

Thanks!
-- 
Florian