[PATCH 19/38] net: atm: add missing put_device call

[PATCH 19/38] net: atm: add missing put_device call

[Levente Kurusa]

This is required so that we give up the last reference to the device.

Signed-off-by: Levente Kurusa <levex@linux.com>
---
 net/atm/atm_sysfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/atm/atm_sysfs.c b/net/atm/atm_sysfs.c
index 350bf62..0e070c2 100644
--- a/net/atm/atm_sysfs.c
+++ b/net/atm/atm_sysfs.c
@@ -154,8 +154,10 @@ int atm_register_sysfs(struct atm_dev *adev, struct device *parent)
 
 	dev_set_name(cdev, "%s%d", adev->type, adev->number);
 	err = device_register(cdev);
-	if (err < 0)
+	if (err < 0) {
+		put_device(cdev);
 		return err;
+	}
 
 	for (i = 0; atm_attrs[i]; i++) {
 		err = device_create_file(cdev, atm_attrs[i]);
-- 
1.8.3.1

Re: [PATCH 19/38] net: atm: add missing put_device call

[David Miller]

From: Levente Kurusa <levex@linux.com>
Date: Thu, 19 Dec 2013 16:03:30 +0100

> This is required so that we give up the last reference to the device.
> 
> Signed-off-by: Levente Kurusa <levex@linux.com>
 ...
> @@ -154,8 +154,10 @@ int atm_register_sysfs(struct atm_dev *adev, struct device *parent)
>  
>  	dev_set_name(cdev, "%s%d", adev->type, adev->number);
>  	err = device_register(cdev);
> -	if (err < 0)
> +	if (err < 0) {
> +		put_device(cdev);
>  		return err;
> +	}

This doesn't make any sense.

Nothing has a reference to 'cdev'.  Yes, 'adev' has a reference,
acquired by the caller of this function, but that's not what we're
working with here.

[PATCH 20/38] net: iucv: add missing put_device call

[Levente Kurusa]

This is required so that we give up the last reference to the device.

Signed-off-by: Levente Kurusa <levex@linux.com>
---
 net/iucv/af_iucv.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index 168aff5..0096206 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -2377,8 +2377,10 @@ static int afiucv_iucv_init(void)
 	af_iucv_dev->release = (void (*)(struct device *))kfree;
 	af_iucv_dev->driver = &af_iucv_driver;
 	err = device_register(af_iucv_dev);
-	if (err)
+	if (err) {
+		put_device(af_iucv_dev);
 		goto out_driver;
+	}
 	return 0;
 
 out_driver:
-- 
1.8.3.1

Re: [PATCH 20/38] net: iucv: add missing put_device call

[David Miller]

From: Levente Kurusa <levex@linux.com>
Date: Thu, 19 Dec 2013 16:03:31 +0100

> This is required so that we give up the last reference to the device.
> 
> Signed-off-by: Levente Kurusa <levex@linux.com>
 ...
> @@ -2377,8 +2377,10 @@ static int afiucv_iucv_init(void)
>  	af_iucv_dev->release = (void (*)(struct device *))kfree;
>  	af_iucv_dev->driver = &af_iucv_driver;
>  	err = device_register(af_iucv_dev);
> -	if (err)
> +	if (err) {
> +		put_device(af_iucv_dev);
>  		goto out_driver;
> +	}

This has the same problem as the ATM patch, there is no reference held on
af_iucv_dev, I mean look at where it comes from:

	af_iucv_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 ...
	dev_set_name(af_iucv_dev, "af_iucv");
	af_iucv_dev->bus = pr_iucv->bus;
	af_iucv_dev->parent = pr_iucv->root;
	af_iucv_dev->release = (void (*)(struct device *))kfree;
	af_iucv_dev->driver = &af_iucv_driver;

No reference count is incremented or set to one for af_iucv_dev.

Please study these code paths more carefully, thank you.