Hi Sakari,
Thank you for the patch.
On Thursday, 13 December 2018 12:40:05 EET Sakari Ailus wrote:
> buf->size is an unsigned long; casting that to int will lead to an
> overflow if buf->size exceeds INT_MAX.
>
> Fix this by changing the type to unsigned long instead. This is possible
> as the buf->size is always aligned to PAGE_SIZE, and therefore the size
> will never have values lesser than 0.
This feels a bit fragile to me. We at least need a big comment in the code to
explain this. Another option would be a size -= min(..., size) just to make
sure.
> Note on backporting to stable: the file used to be under
> drivers/media/v4l2-core, it was moved to the current location after 4.14.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> drivers/media/common/videobuf2/videobuf2-dma-sg.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> b/drivers/media/common/videobuf2/videobuf2-dma-sg.c index
> 015e737095cdd..e9bfea986cc47 100644
> --- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> @@ -59,7 +59,7 @@ static int vb2_dma_sg_alloc_compacted(struct
> vb2_dma_sg_buf *buf, gfp_t gfp_flags)
> {
> unsigned int last_page = 0;
> - int size = buf->size;
> + unsigned long size = buf->size;
>
> while (size > 0) {
> struct page *pages;
--
Regards,
Laurent Pinchart
