Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Niels Dossche <dossche.niels@gmail.com>,
        Marcel Holtmann <marcel@holtmann.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 221/452] Bluetooth: use hdev lock for accept_list and reject_list in conn req
Date:   Tue,  7 Jun 2022 19:01:18 +0200
Message-Id: <20220607164915.147931627@linuxfoundation.org>
In-Reply-To: <20220607164908.521895282@linuxfoundation.org>
References: <20220607164908.521895282@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Niels Dossche <dossche.niels@gmail.com>

[ 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@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 f75869835e3e..954b29605c94 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2709,10 +2709,12 @@ 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
@@ -2724,13 +2726,11 @@ 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);
@@ -2742,8 +2742,7 @@ 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;
 		}
 	}
 
@@ -2783,6 +2782,10 @@ 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