[PATCH] net/wan/fsl_ucc_hdlc: fix out of bounds write on array utdm_info

[Joakim Tjernlund]

On Tue, 2020-01-14 at 14:54 +0000, Colin King wrote:
> 
> From: Colin Ian King <colin.king at canonical.com>
> 
> Array utdm_info is declared as an array of MAX_HDLC_NUM (4) elements
> however up to UCC_MAX_NUM (8) elements are potentially being written
> to it.  Currently we have an array out-of-bounds write error on the
> last 4 elements. Fix this by making utdm_info UCC_MAX_NUM elements in
> size.
> 
> Addresses-Coverity: ("Out-of-bounds write")
> Fixes: c19b6d246a35 ("drivers/net: support hdlc function for QE-UCC")
> Signed-off-by: Colin Ian King <colin.king at canonical.com>

This should be sent to stable as well
Cc: <stable at vger.kernel.org> # 4.19.x+

> ---
>  drivers/net/wan/fsl_ucc_hdlc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
> index 94e870f48e21..9edd94679283 100644
> --- a/drivers/net/wan/fsl_ucc_hdlc.c
> +++ b/drivers/net/wan/fsl_ucc_hdlc.c
> @@ -73,7 +73,7 @@ static struct ucc_tdm_info utdm_primary_info = {
>         },
>  };
> 
> -static struct ucc_tdm_info utdm_info[MAX_HDLC_NUM];
> +static struct ucc_tdm_info utdm_info[UCC_MAX_NUM];
> 
>  static int uhdlc_init(struct ucc_hdlc_private *priv)
>  {
> --
> 2.24.0
>