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

[Andrey Smirnov]

On Tue, May 16, 2017 at 6:44 AM, Johan Hovold <johan@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx>     # 4.3
> Cc: Andrew Lunn <andrew@xxxxxxx>
> Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> ---

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

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

so, FWIW,

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

>  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
>