[PATCHv2] android/gatt: Report error on invalid value length for CCC descriptor

[PATCHv2] android/gatt: Report error on invalid value length for CCC descriptor

[Jakub Tyszkowski]

For application services, characteristics and descriptors it's user
app's responsibility to verify value length but for embeded ones we
need to do this in daemon. This is checked in TC_GAW_SR_BI_34_C and
PTS tries to write to embeded CCC descritor if no other descriptors
are added by the apps. It is expected by PTS for us to be more strict
about value length controll.
---
 android/gatt.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/android/gatt.c b/android/gatt.c
index 0258d91..76df029 100644
--- a/android/gatt.c
+++ b/android/gatt.c
@@ -6961,8 +6961,15 @@ static void gatt_srvc_change_write_cb(struct gatt_db_attribute *attrib,
 		return;
 	}
 
+	/* 2 octets are expected as CCC value */
+	if (len != 2) {
+		gatt_db_attribute_write_result(attrib, id,
+						ATT_ECODE_INVAL_ATTR_VALUE_LEN);
+		return;
+	}
+
 	/* Set services changed indication value */
-	bt_store_gatt_ccc(bdaddr, *value);
+	bt_store_gatt_ccc(bdaddr, get_le16(value));
 
 	gatt_db_attribute_write_result(attrib, id, 0);
 }
-- 
1.9.1

Re: [PATCHv2] android/gatt: Report error on invalid value length for CCC descriptor

[Szymon Janc]

Hi Jakub,

On Friday 19 of December 2014 07:50:14 Jakub Tyszkowski wrote:
> For application services, characteristics and descriptors it's user
> app's responsibility to verify value length but for embeded ones we
> need to do this in daemon. This is checked in TC_GAW_SR_BI_34_C and
> PTS tries to write to embeded CCC descritor if no other descriptors
> are added by the apps. It is expected by PTS for us to be more strict
> about value length controll.
> ---
>  android/gatt.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/android/gatt.c b/android/gatt.c
> index 0258d91..76df029 100644
> --- a/android/gatt.c
> +++ b/android/gatt.c
> @@ -6961,8 +6961,15 @@ static void gatt_srvc_change_write_cb(struct gatt_db_attribute *attrib,
>  		return;
>  	}
>  
> +	/* 2 octets are expected as CCC value */
> +	if (len != 2) {
> +		gatt_db_attribute_write_result(attrib, id,
> +						ATT_ECODE_INVAL_ATTR_VALUE_LEN);
> +		return;
> +	}
> +
>  	/* Set services changed indication value */
> -	bt_store_gatt_ccc(bdaddr, *value);
> +	bt_store_gatt_ccc(bdaddr, get_le16(value));
>  
>  	gatt_db_attribute_write_result(attrib, id, 0);
>  }
> 

Applied, thanks.

-- 
Best regards, 
Szymon Janc