Re: [PATCH] media: media/pci: prevent memory leak in bttv_probe

[butt3rflyh4ck <butterflyhuangxx@gmail.com>]

On Fri, Apr 17, 2020 at 3:26 PM Hans Verkuil <hverkuil-cisco@xs4all.nl> wrote:
>
> On 25/03/2020 10:01, Xiaolong Huang wrote:
> > In bttv_probe if some functions such as pci_enable_device,
> > pci_set_dma_mask and request_mem_region fails the allocated
> >  memory for btv should be released.
> >
> > Signed-off-by: Xiaolong Huang <butterflyhuangxx@gmail.com>
> > ---
> >  drivers/media/pci/bt8xx/bttv-driver.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c
> > index a359da7773a9..37ac59110383 100644
> > --- a/drivers/media/pci/bt8xx/bttv-driver.c
> > +++ b/drivers/media/pci/bt8xx/bttv-driver.c
> > @@ -4013,10 +4013,14 @@ static int bttv_probe(struct pci_dev *dev, const struct pci_device_id *pci_id)
> >       btv->id  = dev->device;
> >       if (pci_enable_device(dev)) {
> >               pr_warn("%d: Can't enable device\n", btv->c.nr);
> > +             bttvs[btv->c.nr] = NULL;
> > +             kfree(btv);
> >               return -EIO;
>
> Let's change this...
>
> >       }
> >       if (pci_set_dma_mask(dev, DMA_BIT_MASK(32))) {
> >               pr_warn("%d: No suitable DMA available\n", btv->c.nr);
> > +             bttvs[btv->c.nr] = NULL;
> > +             kfree(btv);
> >               return -EIO;
>
> this...
>
> >       }
> >       if (!request_mem_region(pci_resource_start(dev,0),
> > @@ -4025,6 +4029,8 @@ static int bttv_probe(struct pci_dev *dev, const struct pci_device_id *pci_id)
> >               pr_warn("%d: can't request iomem (0x%llx)\n",
> >                       btv->c.nr,
> >                       (unsigned long long)pci_resource_start(dev, 0));
> > +             bttvs[btv->c.nr] = NULL;
> > +             kfree(btv);
> >               return -EBUSY;
>
> and this to a goto free_mem.
>
> >       }
> >       pci_set_master(dev);
> > @@ -4211,6 +4217,8 @@ static int bttv_probe(struct pci_dev *dev, const struct pci_device_id *pci_id)
> >       release_mem_region(pci_resource_start(btv->c.pci,0),
> >                          pci_resource_len(btv->c.pci,0));
> >       pci_disable_device(btv->c.pci);
>
> And add the free_mem: label here.
>
> > +     bttvs[btv->c.nr] = NULL;
> > +     kfree(btv);
> >       return result;
> >  }
> >
> >
>
> Regards,
>
>         Hans

Good, I will modify the patch and resend a new one.

Thanks,

      Butt3flyh4ck