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Date:   Wed, 10 Mar 2021 10:42:03 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     Ricardo Ribalda <ribalda@chromium.org>
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
Subject: Re: [PATCH] media: videobuf2: Fix integer overrun in allocation
Message-ID: <YEgj61iAt4Avnp6d@google.com>
References: <20210309234317.1021588-1-ribalda@chromium.org>
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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()?

	-ss