Re: [PATCH -next,v2] nvmem: core: Fix memleak in nvmem_register()

[cuigaosheng]

Thanks for your ideas,

I have made another patch, moving nvmem_validate_keepouts() after
device_register() and let the device core deal with cleaning name in
error cases, it's a better option for the issue.

Thanks,

在 2022/7/18 19:44, Srinivas Kandagatla 写道:
> On 16/07/2022 10:52, Gaosheng Cui wrote:
> > dev_set_name will alloc memory for nvmem->dev.kobj.name in
> > nvmem_register, when nvmem_validate_keepouts failed, nvmem's
> > memory will be freed and return, but nobody will free memory
> > for nvmem->dev.kobj.name, there will be memleak, so moving
> > dev_set_name after nvmem_validate_keepouts to fix it.
> >
> > Fixes: de0534df9347 ("nvmem: core: fix error handling while 
> > validating keepout regions")
> > Signed-off-by: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx>
> > ---
> >   drivers/nvmem/core.c | 28 ++++++++++++++--------------
> >   1 file changed, 14 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> > index 1e3c754efd0d..a5d75edf509d 100644
> > --- a/drivers/nvmem/core.c
> > +++ b/drivers/nvmem/core.c
> > @@ -808,20 +808,6 @@ struct nvmem_device *nvmem_register(const struct 
> > nvmem_config *config)
> >       else if (!config->no_of_node)
> >           nvmem->dev.of_node = config->dev->of_node;
> >   -    switch (config->id) {
> > -    case NVMEM_DEVID_NONE:
> > -        dev_set_name(&nvmem->dev, "%s", config->name);
> > -        break;
> > -    case NVMEM_DEVID_AUTO:
> > -        dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
> > -        break;
> > -    default:
> > -        dev_set_name(&nvmem->dev, "%s%d",
> > -                 config->name ? : "nvmem",
> > -                 config->name ? config->id : nvmem->id);
> > -        break;
> > -    }
> > -
> >       nvmem->read_only = device_property_present(config->dev, 
> > "read-only") ||
> >                  config->read_only || !nvmem->reg_write;
> >   @@ -838,6 +824,20 @@ struct nvmem_device *nvmem_register(const 
> > struct nvmem_config *config)
> >           }
> >       }
> >   +    switch (config->id) {
> > +    case NVMEM_DEVID_NONE:
> > +        dev_set_name(&nvmem->dev, "%s", config->name);
> > +        break;
> > +    case NVMEM_DEVID_AUTO:
> > +        dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
> > +        break;
> > +    default:
> > +        dev_set_name(&nvmem->dev, "%s%d",
> > +                 config->name ? : "nvmem",
> > +                 config->name ? config->id : nvmem->id);
> > +        break;
> > +    }
> > +
> The issue with this approach is that dev_err messages in 
> nvmem_validate_keepouts() will show up without device name setup.
>
> I think better option is to move nvmem_validate_keepouts() after 
> device_register() and let the device core deal with cleaning name in 
> error cases.
>
> --srini
>
> >       dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", 
> > config->name);
> >         rval = device_register(&nvmem->dev);
> .