Re: [PATCH 6.12 597/602] Bluetooth: hci_conn: Fix running bis_cleanup for hci_conn->type PA_LINK

Hi Greg,

On 30/07/26 7:46 pm, Greg Kroah-Hartman wrote:
> 6.12-stable review patch.  If anyone has any objections, please let me know.
> 
> ------------------
> 
> From: Luiz Augusto von Dentz <[email protected]>
> 
> commit d36349ea73d805bb72cbc24ab90cb1da4ad5c379 upstream.
> 
> Connections with type of PA_LINK shall be considered temporary just to
> track the lifetime of PA Sync setup, once the BIG Sync is established
> and connection are created with BIS_LINK the existing PA_LINK
> connection shall not longer use bis_cleanup otherwise it terminates the
> PA Sync when that shall be left to BIS_LINK connection to do it.
> 
> Fixes: a7bcffc673de ("Bluetooth: Add PA_LINK to distinguish BIG sync and PA sync connections")
> Signed-off-by: Luiz Augusto von Dentz <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
> ---
>   net/bluetooth/hci_conn.c  |   10 +++++++++-
>   net/bluetooth/hci_event.c |    7 ++++++-
>   2 files changed, 15 insertions(+), 2 deletions(-)
> 
> --- a/net/bluetooth/hci_conn.c
> +++ b/net/bluetooth/hci_conn.c
> @@ -830,7 +830,15 @@ static void bis_cleanup(struct hci_conn
>   		/* Check if ISO connection is a BIS and terminate advertising
>   		 * set and BIG if there are no other connections using it.
>   		 */
> -		bis = hci_conn_hash_lookup_big(hdev, conn->iso_qos.bcast.big);
> +		bis = hci_conn_hash_lookup_big_state(hdev,
> +						     conn->iso_qos.bcast.big,
> +						     BT_CONNECTED);
> +		if (bis)
> +			return;
> +
> +		bis = hci_conn_hash_lookup_big_state(hdev,
> +						     conn->iso_qos.bcast.big,
> +						     BT_CONNECT);
>   		if (bis)
>   			return;


I have run an AI assisted backport review and it spotted an issue. I
have taken a look, and the two BIG-state lookups lost an upstream role
restriction.

Upstream d36349ea73d8 has:

     hci_conn_hash_lookup_big_state(hdev, big, BT_CONNECTED,
                                    HCI_ROLE_MASTER);

and the same HCI_ROLE_MASTER restriction for BT_CONNECT.

The 6.12.y backport calls the older three-argument helper:

     hci_conn_hash_lookup_big_state(hdev, big, BT_CONNECTED);

That helper accepts either role. The 6.12 tree also creates slave-role
BIS connections during BIG Sync establishment, so a slave BIS with the
same BIG handle and state can satisfy this lookup and suppress cleanup
of the unrelated master BIG.

I think 6.12.y misses commit b2a5f2e1c127
("Bluetooth: hci_event: Add support for handling LE BIG Sync Lost
event"), which adds the role-aware helper and updates its callers, so we 
might want to apply this as well and then reapply this ?


thanks,
Harshit> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -7026,9 +7026,14 @@ static void hci_le_big_sync_established_
>   				continue;
>   		}
>   
> -		if (ev->status != 0x42)
> +		if (ev->status != 0x42) {
>   			/* Mark PA sync as established */
>   			set_bit(HCI_CONN_PA_SYNC, &bis->flags);
> +			/* Reset cleanup callback of PA Sync so it doesn't
> +			 * terminate the sync when deleting the connection.
> +			 */
> +			conn->cleanup = NULL;
> +		}
>   
>   		bis->sync_handle = conn->sync_handle;
>   		bis->iso_qos.bcast.big = ev->handle;
> 
> 
>