Re: [PATCH] ubi: Fix out of bounds write in volume update code

[Boris Brezillon]

On Sun, 21 Feb 2016 10:53:03 +0100
Richard Weinberger <richard@xxxxxx> wrote:

> ubi_start_leb_change() alloctes too few bytes.
> ubi_more_leb_change_data() will write up to req->upd_bytes +
> ubi->min_io_size bytes.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Richard Weinberger <richard@xxxxxx>

Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>

> ---
>  drivers/mtd/ubi/upd.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/ubi/upd.c b/drivers/mtd/ubi/upd.c
> index cfeaf0f..b7901ce 100644
> --- a/drivers/mtd/ubi/upd.c
> +++ b/drivers/mtd/ubi/upd.c
> @@ -193,7 +193,7 @@ int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
>  	vol->changing_leb = 1;
>  	vol->ch_lnum = req->lnum;
>  
> -	vol->upd_buf = vmalloc(req->bytes);
> +	vol->upd_buf = vmalloc(ALIGN((int)req->bytes, ubi->min_io_size));
>  	if (!vol->upd_buf)
>  		return -ENOMEM;
>  



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com