[PATCH v4] Bluetooth: iso: fix socket matching ambiguity between BIS and CIS

[Yang Li via B4 Relay <devnull+yang.li.amlogic.com@kernel.org>]

From: Yang Li <yang.li@amlogic.com>

When both BIS and CIS links exist, their sockets are in
the BT_LISTEN state.
dump sock:
  sk 000000001977ef51 state 6
  src 10:a5:62:31:05:cf dst 00:00:00:00:00:00
  sk 0000000031d28700 state 7
  src 10:a5:62:31:05:cf dst00:00:00:00:00:00
  sk 00000000613af00e state 4   # listen sock of bis
  src 10:a5:62:31:05:cf dst 54:00:00:d4:99:30
  sk 000000001710468c state 9
  src 10:a5:62:31:05:cf dst 54:00:00:d4:99:30
  sk 000000005d97dfde state 4   #listen sock of cis
  src 10:a5:62:31:05:cf dst 00:00:00:00:00:00

To locate the CIS socket correctly, check both the BT_LISTEN
state and whether dst addr is BDADDR_ANY.

Link: https://github.com/bluez/bluez/issues/1224

Signed-off-by: Yang Li <yang.li@amlogic.com>
---
Changes in v4:
- Rebase code.
- Link to v3: https://lore.kernel.org/r/20250731-bis_cis_coexist-v3-1-1f9bd60ef712@amlogic.com
---
 net/bluetooth/iso.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index aa63c8955a53..74ec7d125c88 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -2021,6 +2021,11 @@ static bool iso_match_pa_sync_flag(struct sock *sk, void *data)
 	return test_bit(BT_SK_PA_SYNC, &iso_pi(sk)->flags);
 }
 
+static bool iso_match_dst(struct sock *sk, void *data)
+{
+	return !bacmp(&iso_pi(sk)->dst, (bdaddr_t *)data);
+}
+
 static void iso_conn_ready(struct iso_conn *conn)
 {
 	struct sock *parent = NULL;
@@ -2105,7 +2110,7 @@ static void iso_conn_ready(struct iso_conn *conn)
 
 		if (!parent)
 			parent = iso_get_sock(hdev, &hcon->src, BDADDR_ANY,
-					      BT_LISTEN, NULL, NULL);
+					      BT_LISTEN, iso_match_dst, BDADDR_ANY);
 
 		if (!parent)
 			return;
@@ -2374,7 +2379,7 @@ int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags)
 		}
 	} else {
 		sk = iso_get_sock(hdev, &hdev->bdaddr, BDADDR_ANY,
-				  BT_LISTEN, NULL, NULL);
+				  BT_LISTEN, iso_match_dst, BDADDR_ANY);
 	}
 
 done:

---
base-commit: f63037a3f252522504774c98960282fb776ef3ca
change-id: 20250731-bis_cis_coexist-717a442d5c42

Best regards,
-- 
Yang Li <yang.li@amlogic.com>