Re: [PATCH] tty: vcc: Add check for kstrdup() in vcc_probe()

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Sep 04, 2023 at 11:45:11AM +0800, yiyang (D) wrote:
> On 2023/9/3 18:49, Greg KH wrote:
> > On Sun, Sep 03, 2023 at 06:13:22PM +0800, Yi Yang wrote:
> > > Add check for the return value of kstrdup() and return the error, if it
> > > fails in order to avoid NULL pointer dereference.
> > > 
> > > Fixes: 5d171050e28f ("sparc64: vcc: Enable VCC port probe and removal")
> > > Signed-off-by: Yi Yang <yiyang13@huawei.com>
> > > ---
> > >   drivers/tty/vcc.c | 9 +++++++++
> > >   1 file changed, 9 insertions(+)
> > > 
> > > diff --git a/drivers/tty/vcc.c b/drivers/tty/vcc.c
> > > index a39ed981bfd3..420d334f6077 100644
> > > --- a/drivers/tty/vcc.c
> > > +++ b/drivers/tty/vcc.c
> > > @@ -579,6 +579,10 @@ static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
> > >   		return -ENOMEM;
> > >   	name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL);
> > > +	if (!name) {
> > > +		kfree(port);
> > > +		return -ENOMEM;
> > 
> > Please just add another goto target later in the function like the rest
> > of the error paths follow.
> Ok, i will send v2 patch for this issue.
> > 
> > And how did you test this patch?
> > 
> I use crosstool-ng build sparc arch for open CONFIG_VCC.

That is build-testing, how did you functionally test that this works
properly?

thanks,

greg k-h