[PATCH] nvmem: core: fix leaks on registration errors

[PATCH] nvmem: core: fix leaks on registration errors

[Johan Hovold]

Make sure to deregister and release the nvmem device and underlying
memory on registration errors.

Note that the private data must be freed using put_device() once the
struct device has been initialised.

Also note that there's a related reference leak in the deregistration
function as reported by Mika Westerberg which is being fixed separately.

Fixes: b6c217ab9be6 ("nvmem: Add backwards compatibility support for older EEPROM drivers.")
Fixes: eace75cfdcf7 ("nvmem: Add a simple NVMEM framework for nvmem providers")
Cc: stable <stable@vger.kernel.org>     # 4.3
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/nvmem/core.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 8c830a80a648..6cf916d9db6d 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -489,21 +489,24 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 
 	rval = device_add(&nvmem->dev);
 	if (rval)
-		goto out;
+		goto err_put_device;
 
 	if (config->compat) {
 		rval = nvmem_setup_compat(nvmem, config);
 		if (rval)
-			goto out;
+			goto err_device_del;
 	}
 
 	if (config->cells)
 		nvmem_add_cells(nvmem, config);
 
 	return nvmem;
-out:
-	ida_simple_remove(&nvmem_ida, nvmem->id);
-	kfree(nvmem);
+
+err_device_del:
+	device_del(&nvmem->dev);
+err_put_device:
+	put_device(&nvmem->dev);
+
 	return ERR_PTR(rval);
 }
 EXPORT_SYMBOL_GPL(nvmem_register);
-- 
2.13.0

Re: [PATCH] nvmem: core: fix leaks on registration errors

[Andrey Smirnov]

On Tue, May 16, 2017 at 6:44 AM, Johan Hovold <johan@kernel.org> wrote:
> Make sure to deregister and release the nvmem device and underlying
> memory on registration errors.
>
> Note that the private data must be freed using put_device() once the
> struct device has been initialised.
>
> Also note that there's a related reference leak in the deregistration
> function as reported by Mika Westerberg which is being fixed separately.
>
> Fixes: b6c217ab9be6 ("nvmem: Add backwards compatibility support for older EEPROM drivers.")
> Fixes: eace75cfdcf7 ("nvmem: Add a simple NVMEM framework for nvmem providers")
> Cc: stable <stable@vger.kernel.org>     # 4.3
> Cc: Andrew Lunn <andrew@lunn.ch>
> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---

I submitted identical patch to fix this about a month ago here:

lkml.kernel.org/r/20170418142454.23921-1-andrew.smirnov@gmail.com

so, FWIW,

Acked-by: Andrey Smirnov <andrew.smirnov@gmail.com>

>  drivers/nvmem/core.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> index 8c830a80a648..6cf916d9db6d 100644
> --- a/drivers/nvmem/core.c
> +++ b/drivers/nvmem/core.c
> @@ -489,21 +489,24 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
>
>         rval = device_add(&nvmem->dev);
>         if (rval)
> -               goto out;
> +               goto err_put_device;
>
>         if (config->compat) {
>                 rval = nvmem_setup_compat(nvmem, config);
>                 if (rval)
> -                       goto out;
> +                       goto err_device_del;
>         }
>
>         if (config->cells)
>                 nvmem_add_cells(nvmem, config);
>
>         return nvmem;
> -out:
> -       ida_simple_remove(&nvmem_ida, nvmem->id);
> -       kfree(nvmem);
> +
> +err_device_del:
> +       device_del(&nvmem->dev);
> +err_put_device:
> +       put_device(&nvmem->dev);
> +
>         return ERR_PTR(rval);
>  }
>  EXPORT_SYMBOL_GPL(nvmem_register);
> --
> 2.13.0
>

Re: [PATCH] nvmem: core: fix leaks on registration errors

[Johan Hovold]

On Tue, May 16, 2017 at 02:28:28PM -0700, Andrey Smirnov wrote:
> On Tue, May 16, 2017 at 6:44 AM, Johan Hovold <johan@kernel.org> wrote:
> > Make sure to deregister and release the nvmem device and underlying
> > memory on registration errors.
> >
> > Note that the private data must be freed using put_device() once the
> > struct device has been initialised.
> >
> > Also note that there's a related reference leak in the deregistration
> > function as reported by Mika Westerberg which is being fixed separately.
> >
> > Fixes: b6c217ab9be6 ("nvmem: Add backwards compatibility support for older EEPROM drivers.")
> > Fixes: eace75cfdcf7 ("nvmem: Add a simple NVMEM framework for nvmem providers")
> > Cc: stable <stable@vger.kernel.org>     # 4.3
> > Cc: Andrew Lunn <andrew@lunn.ch>
> > Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> > Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> > Signed-off-by: Johan Hovold <johan@kernel.org>
> > ---
> 
> I submitted identical patch to fix this about a month ago here:
> 
> lkml.kernel.org/r/20170418142454.23921-1-andrew.smirnov@gmail.com

Oh, and you fixed up both the registration and deregistration leaks in
your series too. Looks like the maintainer is on vacation now so perhaps
we'll see a third independent fix for these bugs soon. ;) 

As for your series, I prefer this version for nvmem_register due to the
difference in error label naming (named after what they do rather than
where they are used), but as I also mentioned to Mika, I think just
adding the missing put_device to nvmem_unregister as you did is
preferred.

But the important thing is that this gets fixed.

> so, FWIW,
> 
> Acked-by: Andrey Smirnov <andrew.smirnov@gmail.com>

Thanks,
Johan

> >  drivers/nvmem/core.c | 13 ++++++++-----
> >  1 file changed, 8 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> > index 8c830a80a648..6cf916d9db6d 100644
> > --- a/drivers/nvmem/core.c
> > +++ b/drivers/nvmem/core.c
> > @@ -489,21 +489,24 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
> >
> >         rval = device_add(&nvmem->dev);
> >         if (rval)
> > -               goto out;
> > +               goto err_put_device;
> >
> >         if (config->compat) {
> >                 rval = nvmem_setup_compat(nvmem, config);
> >                 if (rval)
> > -                       goto out;
> > +                       goto err_device_del;
> >         }
> >
> >         if (config->cells)
> >                 nvmem_add_cells(nvmem, config);
> >
> >         return nvmem;
> > -out:
> > -       ida_simple_remove(&nvmem_ida, nvmem->id);
> > -       kfree(nvmem);
> > +
> > +err_device_del:
> > +       device_del(&nvmem->dev);
> > +err_put_device:
> > +       put_device(&nvmem->dev);
> > +
> >         return ERR_PTR(rval);
> >  }
> >  EXPORT_SYMBOL_GPL(nvmem_register);
> > --
> > 2.13.0
> >

Re: [PATCH] nvmem: core: fix leaks on registration errors

[Andrey Smirnov]

On Wed, May 17, 2017 at 1:51 AM, Johan Hovold <johan@kernel.org> wrote:
> On Tue, May 16, 2017 at 02:28:28PM -0700, Andrey Smirnov wrote:
>> On Tue, May 16, 2017 at 6:44 AM, Johan Hovold <johan@kernel.org> wrote:
>> > Make sure to deregister and release the nvmem device and underlying
>> > memory on registration errors.
>> >
>> > Note that the private data must be freed using put_device() once the
>> > struct device has been initialised.
>> >
>> > Also note that there's a related reference leak in the deregistration
>> > function as reported by Mika Westerberg which is being fixed separately.
>> >
>> > Fixes: b6c217ab9be6 ("nvmem: Add backwards compatibility support for older EEPROM drivers.")
>> > Fixes: eace75cfdcf7 ("nvmem: Add a simple NVMEM framework for nvmem providers")
>> > Cc: stable <stable@vger.kernel.org>     # 4.3
>> > Cc: Andrew Lunn <andrew@lunn.ch>
>> > Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> > Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
>> > Signed-off-by: Johan Hovold <johan@kernel.org>
>> > ---
>>
>> I submitted identical patch to fix this about a month ago here:
>>
>> lkml.kernel.org/r/20170418142454.23921-1-andrew.smirnov@gmail.com
>
> Oh, and you fixed up both the registration and deregistration leaks in
> your series too. Looks like the maintainer is on vacation now so perhaps
> we'll see a third independent fix for these bugs soon. ;)
>

Heh, let's hope not :-)

> As for your series, I prefer this version for nvmem_register due to the
> difference in error label naming (named after what they do rather than
> where they are used), but as I also mentioned to Mika, I think just
> adding the missing put_device to nvmem_unregister as you did is
> preferred.
>
> But the important thing is that this gets fixed.
>

Yup, agreed, as long a version of both fixes ends up being applied
it's all good.

Thanks,
Andrey

Re: [PATCH] nvmem: core: fix leaks on registration errors

[Srinivas Kandagatla]

On 16/05/17 14:44, Johan Hovold wrote:
> Make sure to deregister and release the nvmem device and underlying
> memory on registration errors.
>
> Note that the private data must be freed using put_device() once the
> struct device has been initialised.
>
> Also note that there's a related reference leak in the deregistration
> function as reported by Mika Westerberg which is being fixed separately.
>
> Fixes: b6c217ab9be6 ("nvmem: Add backwards compatibility support for older EEPROM drivers.")
> Fixes: eace75cfdcf7 ("nvmem: Add a simple NVMEM framework for nvmem providers")
> Cc: stable <stable@vger.kernel.org>     # 4.3
> Cc: Andrew Lunn <andrew@lunn.ch>
> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
>  drivers/nvmem/core.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)

Thanks for the patch,
Will queue this one along with the "[PATCH 2/2] nvmem: core: Call 
put_device() in nvmem_unregister()" patch from Andrey Smirnov


thanks
srini
>
> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> index 8c830a80a648..6cf916d9db6d 100644
> --- a/drivers/nvmem/core.c
> +++ b/drivers/nvmem/core.c
> @@ -489,21 +489,24 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
>
>  	rval = device_add(&nvmem->dev);
>  	if (rval)
> -		goto out;
> +		goto err_put_device;
>
>  	if (config->compat) {
>  		rval = nvmem_setup_compat(nvmem, config);
>  		if (rval)
> -			goto out;
> +			goto err_device_del;
>  	}
>
>  	if (config->cells)
>  		nvmem_add_cells(nvmem, config);
>
>  	return nvmem;
> -out:
> -	ida_simple_remove(&nvmem_ida, nvmem->id);
> -	kfree(nvmem);
> +
> +err_device_del:
> +	device_del(&nvmem->dev);
> +err_put_device:
> +	put_device(&nvmem->dev);
> +
>  	return ERR_PTR(rval);
>  }
>  EXPORT_SYMBOL_GPL(nvmem_register);
>