Re: [PATCH] dmaengine: idxd: Fix memory leak in idxd_alloc()

[Dave Jiang]

On 9/16/2022 8:36 AM, Jerry Snitselaar wrote:
> On Wed, Sep 14, 2022 at 08:08:14PM -0300, Rafael Mendonca wrote:
> > If the IDA id allocation fails, then the allocated memory for the
> > idxd_device struct doesn't get freed before returning NULL, which leads to
> > a memleak.
> >
> > Fixes: 47c16ac27d4c ("dmaengine: idxd: fix idxd conf_dev 'struct device' lifetime")
> > Signed-off-by: Rafael Mendonca <rafaelmendsr@xxxxxxxxx>
> I think there needs to be a kfree(idxd) where it checks rc < 0 after the call to dev_set_name() as well, yes?
The idxd_conf_device_release() should take care of freeing idxd with the 
put_device(). So I think we are good here.
> Regards,
> Jerry
>
> > ---
> >   drivers/dma/idxd/init.c | 4 +++-
> >   1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
> > index aa3478257ddb..fdc97519b8fb 100644
> > --- a/drivers/dma/idxd/init.c
> > +++ b/drivers/dma/idxd/init.c
> > @@ -445,8 +445,10 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d
> >   	idxd->data = data;
> >   	idxd_dev_set_type(&idxd->idxd_dev, idxd->data->type);
> >   	idxd->id = ida_alloc(&idxd_ida, GFP_KERNEL);
> > -	if (idxd->id < 0)
> > +	if (idxd->id < 0) {
> > +		kfree(idxd);
> >   		return NULL;
> > +	}
> >   
> >   	device_initialize(conf_dev);
> >   	conf_dev->parent = dev;
> > --
> > 2.34.1