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* [PATCH] cpuidle: Fix memory leaks
@ 2021-09-06 18:34 Anel Orazgaliyeva
  2021-09-15 12:14 ` Rafael J. Wysocki
  0 siblings, 1 reply; 4+ messages in thread
From: Anel Orazgaliyeva @ 2021-09-06 18:34 UTC (permalink / raw)
  Cc: anelkz, Aman Priyadarshi, Rafael J. Wysocki, Daniel Lezcano,
	linux-pm, linux-kernel

Commit c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
fixes the cleanup of kobjects; however, it removes kfree() calls
altogether, leading to memory leaks.

Fix those and also defer the initialization of dev->kobj_dev until
after the error check, so that we do not end up with a dangling
pointer.

Signed-off-by: Anel Orazgaliyeva <anelkz@amazon.de>
Suggested-by: Aman Priyadarshi <apeureka@amazon.de>
---
 drivers/cpuidle/sysfs.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index 53ec9585ccd4..469e18547d06 100644
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -488,6 +488,7 @@ static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 					   &kdev->kobj, "state%d", i);
 		if (ret) {
 			kobject_put(&kobj->kobj);
+			kfree(kobj);
 			goto error_state;
 		}
 		cpuidle_add_s2idle_attr_group(kobj);
@@ -619,6 +620,7 @@ static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 				   &kdev->kobj, "driver");
 	if (ret) {
 		kobject_put(&kdrv->kobj);
+		kfree(kdrv);
 		return ret;
 	}
 
@@ -705,7 +707,6 @@ int cpuidle_add_sysfs(struct cpuidle_device *dev)
 	if (!kdev)
 		return -ENOMEM;
 	kdev->dev = dev;
-	dev->kobj_dev = kdev;
 
 	init_completion(&kdev->kobj_unregister);
 
@@ -713,9 +714,11 @@ int cpuidle_add_sysfs(struct cpuidle_device *dev)
 				   "cpuidle");
 	if (error) {
 		kobject_put(&kdev->kobj);
+		kfree(kdev);
 		return error;
 	}
 
+	dev->kobj_dev = kdev;
 	kobject_uevent(&kdev->kobj, KOBJ_ADD);
 
 	return 0;
-- 
2.32.0




Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879




^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] cpuidle: Fix memory leaks
  2021-09-06 18:34 [PATCH] cpuidle: Fix memory leaks Anel Orazgaliyeva
@ 2021-09-15 12:14 ` Rafael J. Wysocki
  2021-09-15 15:44   ` Anel Orazgaliyeva
  0 siblings, 1 reply; 4+ messages in thread
From: Rafael J. Wysocki @ 2021-09-15 12:14 UTC (permalink / raw)
  To: Anel Orazgaliyeva
  Cc: Aman Priyadarshi, Rafael J. Wysocki, Daniel Lezcano, Linux PM,
	Linux Kernel Mailing List

On Mon, Sep 6, 2021 at 8:35 PM Anel Orazgaliyeva <anelkz@amazon.de> wrote:
>
> Commit c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
> fixes the cleanup of kobjects; however, it removes kfree() calls
> altogether, leading to memory leaks.

Wait, won't the cleanup be done by cpuidle_free_state_kobj()?

> Fix those and also defer the initialization of dev->kobj_dev until
> after the error check, so that we do not end up with a dangling
> pointer.
>
> Signed-off-by: Anel Orazgaliyeva <anelkz@amazon.de>
> Suggested-by: Aman Priyadarshi <apeureka@amazon.de>
> ---
>  drivers/cpuidle/sysfs.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
> index 53ec9585ccd4..469e18547d06 100644
> --- a/drivers/cpuidle/sysfs.c
> +++ b/drivers/cpuidle/sysfs.c
> @@ -488,6 +488,7 @@ static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
>                                            &kdev->kobj, "state%d", i);
>                 if (ret) {
>                         kobject_put(&kobj->kobj);
> +                       kfree(kobj);
>                         goto error_state;
>                 }
>                 cpuidle_add_s2idle_attr_group(kobj);
> @@ -619,6 +620,7 @@ static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
>                                    &kdev->kobj, "driver");
>         if (ret) {
>                 kobject_put(&kdrv->kobj);
> +               kfree(kdrv);
>                 return ret;
>         }
>
> @@ -705,7 +707,6 @@ int cpuidle_add_sysfs(struct cpuidle_device *dev)
>         if (!kdev)
>                 return -ENOMEM;
>         kdev->dev = dev;
> -       dev->kobj_dev = kdev;
>
>         init_completion(&kdev->kobj_unregister);
>
> @@ -713,9 +714,11 @@ int cpuidle_add_sysfs(struct cpuidle_device *dev)
>                                    "cpuidle");
>         if (error) {
>                 kobject_put(&kdev->kobj);
> +               kfree(kdev);
>                 return error;
>         }
>
> +       dev->kobj_dev = kdev;
>         kobject_uevent(&kdev->kobj, KOBJ_ADD);
>
>         return 0;
> --
> 2.32.0
>
>
>
>
> Amazon Development Center Germany GmbH
> Krausenstr. 38
> 10117 Berlin
> Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
> Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
> Sitz: Berlin
> Ust-ID: DE 289 237 879
>
>
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] cpuidle: Fix memory leaks
  2021-09-15 12:14 ` Rafael J. Wysocki
@ 2021-09-15 15:44   ` Anel Orazgaliyeva
  2021-10-01 18:45     ` Rafael J. Wysocki
  0 siblings, 1 reply; 4+ messages in thread
From: Anel Orazgaliyeva @ 2021-09-15 15:44 UTC (permalink / raw)
  To: Rafael J. Wysocki
  Cc: Aman Priyadarshi, Daniel Lezcano, linux-pm, linux-kernel

> On Wed, Sep 15, 2021 at 02:14:56PM +0200, Rafael J. Wysocki wrote:
> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
> 
> 
> 
> On Mon, Sep 6, 2021 at 8:35 PM Anel Orazgaliyeva <anelkz@amazon.de> wrote:
> >
> > Commit c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
> > fixes the cleanup of kobjects; however, it removes kfree() calls
> > altogether, leading to memory leaks.
> 
> Wait, won't the cleanup be done by cpuidle_free_state_kobj()?

For state cleanup, cpuidle_free_state_kobj() is called on the all the previously created kobjs:

error_state:
        for (i = i - 1; i >= 0; i--)
                cpuidle_free_state_kobj(device, i);

so we still need to cleanup the kobj created in the current iteration.


For overall sysfs, the flow is as follows:

cpuidle_register_device
     ret = cpuidle_add_sysfs(dev);
    if (ret)
        goto out_unregister;

out_unregister:
    __cpuidle_unregister_device(dev);
   goto out_unlock;

so when there is an error in cpuidle_add_sysfs() dev doesn’t get freed.

> 
> > Fix those and also defer the initialization of dev->kobj_dev until
> > after the error check, so that we do not end up with a dangling
> > pointer.
> >
> > Signed-off-by: Anel Orazgaliyeva <anelkz@amazon.de>
> > Suggested-by: Aman Priyadarshi <apeureka@amazon.de>
> > ---
> >  drivers/cpuidle/sysfs.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
> > index 53ec9585ccd4..469e18547d06 100644
> > --- a/drivers/cpuidle/sysfs.c
> > +++ b/drivers/cpuidle/sysfs.c
> > @@ -488,6 +488,7 @@ static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
> >                                            &kdev->kobj, "state%d", i);
> >                 if (ret) {
> >                         kobject_put(&kobj->kobj);
> > +                       kfree(kobj);
> >                         goto error_state;
> >                 }
> >                 cpuidle_add_s2idle_attr_group(kobj);
> > @@ -619,6 +620,7 @@ static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
> >                                    &kdev->kobj, "driver");
> >         if (ret) {
> >                 kobject_put(&kdrv->kobj);
> > +               kfree(kdrv);
> >                 return ret;
> >         }
> >
> > @@ -705,7 +707,6 @@ int cpuidle_add_sysfs(struct cpuidle_device *dev)
> >         if (!kdev)
> >                 return -ENOMEM;
> >         kdev->dev = dev;
> > -       dev->kobj_dev = kdev;
> >
> >         init_completion(&kdev->kobj_unregister);
> >
> > @@ -713,9 +714,11 @@ int cpuidle_add_sysfs(struct cpuidle_device *dev)
> >                                    "cpuidle");
> >         if (error) {
> >                 kobject_put(&kdev->kobj);
> > +               kfree(kdev);
> >                 return error;
> >         }
> >
> > +       dev->kobj_dev = kdev;
> >         kobject_uevent(&kdev->kobj, KOBJ_ADD);
> >
> >         return 0;
> > --
> > 2.32.0
> >
> >
> >
> >
> > Amazon Development Center Germany GmbH
> > Krausenstr. 38
> > 10117 Berlin
> > Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
> > Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
> > Sitz: Berlin
> > Ust-ID: DE 289 237 879

On Wed, Sep 15, 2021 at 02:14:56PM +0200, Rafael J. Wysocki wrote:
> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
> 
> 
> 
> On Mon, Sep 6, 2021 at 8:35 PM Anel Orazgaliyeva <anelkz@amazon.de> wrote:
> >
> > Commit c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
> > fixes the cleanup of kobjects; however, it removes kfree() calls
> > altogether, leading to memory leaks.
> 
> Wait, won't the cleanup be done by cpuidle_free_state_kobj()?
> 
> > Fix those and also defer the initialization of dev->kobj_dev until
> > after the error check, so that we do not end up with a dangling
> > pointer.
> >
> > Signed-off-by: Anel Orazgaliyeva <anelkz@amazon.de>
> > Suggested-by: Aman Priyadarshi <apeureka@amazon.de>
> > ---
> >  drivers/cpuidle/sysfs.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
> > index 53ec9585ccd4..469e18547d06 100644
> > --- a/drivers/cpuidle/sysfs.c
> > +++ b/drivers/cpuidle/sysfs.c
> > @@ -488,6 +488,7 @@ static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
> >                                            &kdev->kobj, "state%d", i);
> >                 if (ret) {
> >                         kobject_put(&kobj->kobj);
> > +                       kfree(kobj);
> >                         goto error_state;
> >                 }
> >                 cpuidle_add_s2idle_attr_group(kobj);
> > @@ -619,6 +620,7 @@ static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
> >                                    &kdev->kobj, "driver");
> >         if (ret) {
> >                 kobject_put(&kdrv->kobj);
> > +               kfree(kdrv);
> >                 return ret;
> >         }
> >
> > @@ -705,7 +707,6 @@ int cpuidle_add_sysfs(struct cpuidle_device *dev)
> >         if (!kdev)
> >                 return -ENOMEM;
> >         kdev->dev = dev;
> > -       dev->kobj_dev = kdev;
> >
> >         init_completion(&kdev->kobj_unregister);
> >
> > @@ -713,9 +714,11 @@ int cpuidle_add_sysfs(struct cpuidle_device *dev)
> >                                    "cpuidle");
> >         if (error) {
> >                 kobject_put(&kdev->kobj);
> > +               kfree(kdev);
> >                 return error;
> >         }
> >
> > +       dev->kobj_dev = kdev;
> >         kobject_uevent(&kdev->kobj, KOBJ_ADD);
> >
> >         return 0;
> > --
> > 2.32.0
> >
> >
> >
> >
> > Amazon Development Center Germany GmbH
> > Krausenstr. 38
> > 10117 Berlin
> > Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
> > Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
> > Sitz: Berlin
> > Ust-ID: DE 289 237 879
> >
> >
> >



Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879



^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] cpuidle: Fix memory leaks
  2021-09-15 15:44   ` Anel Orazgaliyeva
@ 2021-10-01 18:45     ` Rafael J. Wysocki
  0 siblings, 0 replies; 4+ messages in thread
From: Rafael J. Wysocki @ 2021-10-01 18:45 UTC (permalink / raw)
  To: Anel Orazgaliyeva
  Cc: Rafael J. Wysocki, Aman Priyadarshi, Daniel Lezcano, Linux PM,
	Linux Kernel Mailing List

On Wed, Sep 15, 2021 at 5:45 PM Anel Orazgaliyeva <anelkz@amazon.de> wrote:
>
> > On Wed, Sep 15, 2021 at 02:14:56PM +0200, Rafael J. Wysocki wrote:
> > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
> >
> >
> >
> > On Mon, Sep 6, 2021 at 8:35 PM Anel Orazgaliyeva <anelkz@amazon.de> wrote:
> > >
> > > Commit c343bf1ba5ef ("cpuidle: Fix three reference count leaks")
> > > fixes the cleanup of kobjects; however, it removes kfree() calls
> > > altogether, leading to memory leaks.
> >
> > Wait, won't the cleanup be done by cpuidle_free_state_kobj()?
>
> For state cleanup, cpuidle_free_state_kobj() is called on the all the previously created kobjs:
>
> error_state:
>         for (i = i - 1; i >= 0; i--)
>                 cpuidle_free_state_kobj(device, i);
>
> so we still need to cleanup the kobj created in the current iteration.
>
>
> For overall sysfs, the flow is as follows:
>
> cpuidle_register_device
>      ret = cpuidle_add_sysfs(dev);
>     if (ret)
>         goto out_unregister;
>
> out_unregister:
>     __cpuidle_unregister_device(dev);
>    goto out_unlock;
>
> so when there is an error in cpuidle_add_sysfs() dev doesn’t get freed.

OK, applied as 5.16 material, thanks!

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-10-01 18:45 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2021-09-06 18:34 [PATCH] cpuidle: Fix memory leaks Anel Orazgaliyeva
2021-09-15 12:14 ` Rafael J. Wysocki
2021-09-15 15:44   ` Anel Orazgaliyeva
2021-10-01 18:45     ` Rafael J. Wysocki

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