Re: [PATCH] dma-buf: free dmabuf->name in dma_buf_release()

From: Cong Wang <xiyou.wangcong@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
	LKML <linux-kernel@vger.kernel.org>,
	linaro-mm-sig@lists.linaro.org,
	syzbot+b2098bc44728a4efb3e9@syzkaller.appspotmail.com,
	Chenbo Feng <fengc@google.com>,
	Sumit Semwal <sumit.semwal@linaro.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH] dma-buf: free dmabuf->name in dma_buf_release()
Date: Thu, 27 Feb 2020 13:38:03 -0800	[thread overview]
Message-ID: <CAM_iQpU7kXXGuxeOVvAGLoBRvjrhpuw2D=ih=PagGXKK-g_muw@mail.gmail.com> (raw)
In-Reply-To: <20200225175418.2d3af2180cbf895b727ce4b1@linux-foundation.org>

On Tue, Feb 25, 2020 at 5:54 PM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Tue, 25 Feb 2020 12:44:46 -0800 Cong Wang <xiyou.wangcong@gmail.com> wrote:
>
> > dma-buff name can be set via DMA_BUF_SET_NAME ioctl, but once set
> > it never gets freed.
> >
> > Free it in dma_buf_release().
> >
> > ...
> >
> > --- a/drivers/dma-buf/dma-buf.c
> > +++ b/drivers/dma-buf/dma-buf.c
> > @@ -108,6 +108,7 @@ static int dma_buf_release(struct inode *inode, struct file *file)
> >               dma_resv_fini(dmabuf->resv);
> >
> >       module_put(dmabuf->owner);
> > +     kfree(dmabuf->name);
> >       kfree(dmabuf);
> >       return 0;
> >  }
>
> ow.  Is that ioctl privileged?

It looks unprivileged to me, as I don't see capable() called along
the path.

Thanks.