Re: [PATCH] dax/hmem: Fix refcount leak in dax_hmem_probe()

[Yongqiang Liu]

在 2022/12/4 4:49, Ira Weiny 写道:
> On Sat, Dec 03, 2022 at 09:58:58AM +0000, Yongqiang Liu wrote:
> > We should always call dax_region_put() whenever devm_create_dev_dax()
> > succeed or fail to avoid refcount leak of dax_region. Move the return
> > value check after dax_region_put().
> I think dax_region_put is called from dax_region_unregister() automatically on
> tear down.
Yes, Thanks for your explanation.
> > Fixes: c01044cc8191 ("ACPI: HMAT: refactor hmat_register_target_device to hmem_register_device")
> I'm also not sure how this patch is related to this fix.
>
> Ira
>
> > Signed-off-by: Yongqiang Liu <liuyongqiang13@xxxxxxxxxx>
> > ---
> >   drivers/dax/hmem/hmem.c | 5 ++---
> >   1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
> > index 1bf040dbc834..09f5cd7b6c8e 100644
> > --- a/drivers/dax/hmem/hmem.c
> > +++ b/drivers/dax/hmem/hmem.c
> > @@ -36,12 +36,11 @@ static int dax_hmem_probe(struct platform_device *pdev)
> >   		.size = region_idle ? 0 : resource_size(res),
> >   	};
> >   	dev_dax = devm_create_dev_dax(&data);
> > -	if (IS_ERR(dev_dax))
> > -		return PTR_ERR(dev_dax);
> >   
> >   	/* child dev_dax instances now own the lifetime of the dax_region */
> >   	dax_region_put(dax_region);
> > -	return 0;
> > +
> > +	return IS_ERR(dev_dax) ? PTR_ERR(dev_dax) : 0;
> >   }
> >   
> >   static int dax_hmem_remove(struct platform_device *pdev)
> > --
> > 2.25.1
> .