NAK: [SRU][N/J][PATCH 1/1] Bluetooth: L2CAP: Fix rejecting L2CAP_CONN_PARAM_UPDATE_REQ

[Agathe Porte]

2024-07-23 12:52 KST, Yo-Jung (Leo) Lin:
> From: Luiz Augusto von Dentz <luiz.von.dentz at intel.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/2072858
> 
> This removes the bogus check for max > hcon->le_conn_max_interval since
> the later is just the initial maximum conn interval not the maximum the
> stack could support which is really 3200=4000ms.
> 
> In order to pass GAP/CONN/CPUP/BV-05-C one shall probably enter values
> of the following fields in IXIT that would cause hci_check_conn_params
> to fail:
> 
> TSPX_conn_update_int_min
> TSPX_conn_update_int_max
> TSPX_conn_update_peripheral_latency
> TSPX_conn_update_supervision_timeout
> 
> Link: https://github.com/bluez/bluez/issues/847
> Fixes: e4b019515f95 ("Bluetooth: Enforce validation on max value of connection interval")
> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz at intel.com>
> (cherry picked from commit 806a5198c05987b748b50f3d0c0cfb3d417381a4 linux-next)
> Signed-off-by: Yo-Jung (Leo) Lin <leo.lin at canonical.com>
> ---
>  include/net/bluetooth/hci_core.h | 36 ++++++++++++++++++++++++++++----
>  net/bluetooth/l2cap_core.c       |  8 +------
>  2 files changed, 33 insertions(+), 11 deletions(-)
> 
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index 5277c6d5134c..c4781aec3c08 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -2114,18 +2114,46 @@ static inline int hci_check_conn_params(u16 min, u16 max, u16 latency,
>  {
>  	u16 max_latency;
>  
> -	if (min > max || min < 6 || max > 3200)
> +	if (min > max) {
> +		BT_WARN("min %d > max %d", min, max);
>  		return -EINVAL;
> +	}
> +
> +	if (min < 6) {
> +		BT_WARN("min %d < 6", min);
> +		return -EINVAL;
> +	}
> +
> +	if (max > 3200) {
> +		BT_WARN("max %d > 3200", max);
> +		return -EINVAL;
> +	}
> +
> +	if (to_multiplier < 10) {
> +		BT_WARN("to_multiplier %d < 10", to_multiplier);
> +		return -EINVAL;
> +	}
>  
> -	if (to_multiplier < 10 || to_multiplier > 3200)
> +	if (to_multiplier > 3200) {
> +		BT_WARN("to_multiplier %d > 3200", to_multiplier);
>  		return -EINVAL;
> +	}
>  
> -	if (max >= to_multiplier * 8)
> +	if (max >= to_multiplier * 8) {
> +		BT_WARN("max %d >= to_multiplier %d * 8", max, to_multiplier);
>  		return -EINVAL;
> +	}
>  
>  	max_latency = (to_multiplier * 4 / max) - 1;
> -	if (latency > 499 || latency > max_latency)
> +	if (latency > 499) {
> +		BT_WARN("latency %d > 499", latency);
>  		return -EINVAL;
> +	}
> +
> +	if (latency > max_latency) {
> +		BT_WARN("latency %d > max_latency %d", latency, max_latency);
> +		return -EINVAL;
> +	}
>  
>  	return 0;
>  }
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index 4a633c1b6882..e3f5d830e42b 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -4645,13 +4645,7 @@ static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
>  
>  	memset(&rsp, 0, sizeof(rsp));
>  
> -	if (max > hcon->le_conn_max_interval) {
> -		BT_DBG("requested connection interval exceeds current bounds.");
> -		err = -EINVAL;
> -	} else {
> -		err = hci_check_conn_params(min, max, latency, to_multiplier);
> -	}
> -
> +	err = hci_check_conn_params(min, max, latency, to_multiplier);
>  	if (err)
>  		rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
>  	else

Missing cover letter email.