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Date:   Wed, 23 Nov 2022 12:04:33 +0000
From:   John Keeping <john@metanate.com>
To:     Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Cc:     linux-usb@vger.kernel.org,
        Fabien Chouteau <fabien.chouteau@barco.com>,
        Peter Korsgaard <peter.korsgaard@barco.com>,
        Felipe Balbi <balbi@ti.com>,
        Andrzej Pietrasiewicz <andrzej.p@samsung.com>,
        linux-kernel@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Lee Jones <lee@kernel.org>,
        Alan Stern <stern@rowland.harvard.edu>
Subject: Re: [PATCH 2/3] usb: gadget: f_hid: fix refcount leak on error path
Message-ID: <Y34MUUyOSgwLWQA+@donbot>
References: <20221122123523.3068034-1-john@metanate.com>
 <20221122123523.3068034-3-john@metanate.com>
 <dcd180f6-7769-3bc5-403f-8960e922bb50@collabora.com>
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On Wed, Nov 23, 2022 at 12:55:14PM +0100, Andrzej Pietrasiewicz wrote:
> W dniu 22.11.2022 o?13:35, John Keeping pisze:
> > When failing to allocate report_desc, opts->refcnt has already been
> > incremented so it needs to be decremented to avoid leaving the options
> > structure permanently locked.
> > 
> > Fixes: 21a9476a7ba8 ("usb: gadget: hid: add configfs support")
> > Signed-off-by: John Keeping <john@metanate.com>
> 
> I'd personally place the bugfix before patches 1 and 3, but anyway

Patch 1 is also a bugfix, I ordered 1 & 2 based on the order of the
commits in the Fixes: tags.

> Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
> 
> > ---
> >   drivers/usb/gadget/function/f_hid.c | 1 +
> >   1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
> > index 8b8bbeaa27cb..6be6009f911e 100644
> > --- a/drivers/usb/gadget/function/f_hid.c
> > +++ b/drivers/usb/gadget/function/f_hid.c
> > @@ -1292,6 +1292,7 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
> >   						 GFP_KERNEL);
> >   		if (!hidg->report_desc) {
> >   			put_device(&hidg->dev);
> > +			--opts->refcnt;
> >   			mutex_unlock(&opts->lock);
> >   			return ERR_PTR(-ENOMEM);
> >   		}
>