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References: <20210309234317.1021588-1-ribalda@chromium.org> <YEgj61iAt4Avnp6d@google.com>
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From:   Ricardo Ribalda <ribalda@chromium.org>
Date:   Wed, 10 Mar 2021 08:40:24 +0100
Message-ID: <CANiDSCuVvhRXGHch0EvJ22mU+bfVs7ZyT2vrnWPxNu0z-ja_1g@mail.gmail.com>
Subject: Re: [PATCH] media: videobuf2: Fix integer overrun in allocation
To:     Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc:     Tomasz Figa <tfiga@chromium.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        stable@vger.kernel.org
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Hi Sergey

On Wed, Mar 10, 2021 at 2:42 AM Sergey Senozhatsky
<sergey.senozhatsky.work@gmail.com> wrote:
>
> On (21/03/10 00:43), Ricardo Ribalda wrote:
> > The plane_length is an unsigned integer. So, if we have a size of
> > 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32.
>
> Hi Ricardo,
>
> > @@ -223,8 +223,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
> >        * NOTE: mmapped areas should be page aligned
> >        */
> >       for (plane = 0; plane < vb->num_planes; ++plane) {
> > +             unsigned long size = vb->planes[plane].length;
> > +
> >               /* Memops alloc requires size to be page aligned. */
> > -             unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
> > +             size = PAGE_ALIGN(size);
> >
> >               /* Did it wrap around? */
> >               if (size < vb->planes[plane].length)
>
> Shouldn't the same be done in vb2_mmap()?
Indeed, I was having tunnel vision focussing on my issue.

I have sent a new patch.

Thanks!
>
>         -ss


--
Ricardo Ribalda