[PATCH 5.15 331/667] Bluetooth: use hdev lock for accept_list and reject_list in conn req

[Greg Kroah-Hartman]

From: Niels Dossche <dossche.niels@xxxxxxxxx>

[ Upstream commit fb048cae51bacdfbbda2954af3c213fdb1d484f4 ]

All accesses (both reads and modifications) to
hdev->{accept,reject}_list are protected by hdev lock,
except the ones in hci_conn_request_evt. This can cause a race
condition in the form of a list corruption.
The solution is to protect these lists in hci_conn_request_evt as well.

I was unable to find the exact commit that introduced the issue for the
reject list, I was only able to find it for the accept list.

Fixes: a55bd29d5227 ("Bluetooth: Add white list lookup for incoming connection requests")
Signed-off-by: Niels Dossche <dossche.niels@xxxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/bluetooth/hci_event.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index e984a8b4b914..5ac3aca6deeb 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2790,10 +2790,12 @@ static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
 		return;
 	}
 
+	hci_dev_lock(hdev);
+
 	if (hci_bdaddr_list_lookup(&hdev->reject_list, &ev->bdaddr,
 				   BDADDR_BREDR)) {
 		hci_reject_conn(hdev, &ev->bdaddr);
-		return;
+		goto unlock;
 	}
 
 	/* Require HCI_CONNECTABLE or an accept list entry to accept the
@@ -2805,13 +2807,11 @@ static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
 	    !hci_bdaddr_list_lookup_with_flags(&hdev->accept_list, &ev->bdaddr,
 					       BDADDR_BREDR)) {
 		hci_reject_conn(hdev, &ev->bdaddr);
-		return;
+		goto unlock;
 	}
 
 	/* Connection accepted */
 
-	hci_dev_lock(hdev);
-
 	ie = hci_inquiry_cache_lookup(hdev, &ev->bdaddr);
 	if (ie)
 		memcpy(ie->data.dev_class, ev->dev_class, 3);
@@ -2823,8 +2823,7 @@ static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
 				    HCI_ROLE_SLAVE);
 		if (!conn) {
 			bt_dev_err(hdev, "no memory for new connection");
-			hci_dev_unlock(hdev);
-			return;
+			goto unlock;
 		}
 	}
 
@@ -2864,6 +2863,10 @@ static void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
 		conn->state = BT_CONNECT2;
 		hci_connect_cfm(conn, 0);
 	}
+
+	return;
+unlock:
+	hci_dev_unlock(hdev);
 }
 
 static u8 hci_to_mgmt_reason(u8 err)
-- 
2.35.1