Re: [PATCH] drivers: base: transport_class: fix possible memory leak

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Nov 10, 2022 at 04:44:16PM +0800, Yang Yingliang wrote:
> Hi Greg,
> 
> On 2022/11/10 16:18, Greg KH wrote:
> > On Thu, Nov 10, 2022 at 11:48:09AM +0800, Yang Yingliang wrote:
> > > Current some drivers(like iscsi) call transport_register_device()
> > > failed, they don't call transport_destroy_device() to release the
> > > memory allocated in transport_setup_device(), because they don't
> > > know what was done, it should be internal thing to release the
> > > resource in register function. So fix this leak by calling destroy
> > > function inside register function.
> > > 
> > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> > > Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> > > ---
> > >   include/linux/transport_class.h | 9 ++++++++-
> > >   1 file changed, 8 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/include/linux/transport_class.h b/include/linux/transport_class.h
> > > index 63076fb835e3..f4835250bbfc 100644
> > > --- a/include/linux/transport_class.h
> > > +++ b/include/linux/transport_class.h
> > > @@ -70,8 +70,15 @@ void transport_destroy_device(struct device *);
> > >   static inline int
> > >   transport_register_device(struct device *dev)
> > >   {
> > > +	int ret;
> > > +
> > >   	transport_setup_device(dev);
> > > -	return transport_add_device(dev);
> > > +	ret = transport_add_device(dev);
> > > +	if (ret) {
> > > +		transport_destroy_device(dev);
> > > +	}
> > Please use scripts/checkpatch.pl on your patches before sending them out
> Sure, of course. :)
> > so you don't get grumpy maintainers asking you to use
> > scripts/checkpatch.pl on your patches :)
> I sent a fix patch to iscsi system earlier:
> https://patchwork.kernel.org/project/linux-scsi/patch/20221109092421.3111613-1-yangyingliang@huawei.com/
> 
> Mike give his point in the mail, so I send a new patch keep iscsi
> maintainers Cced.

That's fine, but the code you wrote here should look different as it
does not follow our coding style rules.  That is the point I was trying
to make.

thanks,

greg k-h