[PATCH] UBI: Validate data_size

[David Gstir]

> On 22.09.2015, at 23:58, Richard Weinberger <richard at nod.at> wrote:
> 
> Make sure that data_size is less than LEB size.
> Otherwise a handcrafted UBI image is able to trigger
> an out of bounds memory access in ubi_compare_lebs().
> 
> Cc: stable at vger.kernel.org
> Signed-off-by: Richard Weinberger <richard at nod.at>
> ---
> drivers/mtd/ubi/io.c | 5 +++++
> 1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
> index 5bbd1f0..1fc23e4 100644
> --- a/drivers/mtd/ubi/io.c
> +++ b/drivers/mtd/ubi/io.c
> @@ -926,6 +926,11 @@ static int validate_vid_hdr(const struct ubi_device *ubi,
> 		goto bad;
> 	}
> 
> +	if (data_size > ubi->leb_size) {
> +		ubi_err(ubi, "bad data_size");
> +		goto bad;
> +	}
> +

Nice catch!

Reviewed-by: David Gstir <david at sigma-star.at>