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From: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
To: linux-bluetooth@vger.kernel.org
Subject: [PATCH v2 1/3] Bluetooth: hci_conn: Fix UAF Write in __hci_acl_create_connection_sync
Date: Tue, 13 Feb 2024 16:31:21 -0500
Message-ID: <20240213213123.403654-1-luiz.dentz@gmail.com>
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From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This fixes the UAF on __hci_acl_create_connection_sync caused by
connection abortion, it uses the same logic as to LE_LINK which uses
hci_cmd_sync_cancel to prevent the callback to run if the connection is
abort prematurely.

Reported-by: syzbot+3f0a39be7a2035700868@syzkaller.appspotmail.com
Fixes: 456561ba8e49 ("Bluetooth: hci_conn: Only do ACL connections sequentially")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 include/net/bluetooth/hci_sync.h |  3 +--
 net/bluetooth/hci_conn.c         |  3 ++-
 net/bluetooth/hci_sync.c         | 16 ++++++++++------
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/include/net/bluetooth/hci_sync.h b/include/net/bluetooth/hci_sync.h
index 824660f8f30d..ed334c253ebc 100644
--- a/include/net/bluetooth/hci_sync.h
+++ b/include/net/bluetooth/hci_sync.h
@@ -139,5 +139,4 @@ int hci_le_big_terminate_sync(struct hci_dev *hdev, u8 handle);
 
 int hci_le_pa_terminate_sync(struct hci_dev *hdev, u16 handle);
 
-int hci_acl_create_connection_sync(struct hci_dev *hdev,
-				   struct hci_conn *conn);
+int hci_connect_acl_sync(struct hci_dev *hdev, struct hci_conn *conn);
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 8164502234c5..587eb27f374c 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1645,7 +1645,7 @@ struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
 		acl->auth_type = auth_type;
 		acl->conn_timeout = timeout;
 
-		err = hci_acl_create_connection_sync(hdev, acl);
+		err = hci_connect_acl_sync(hdev, acl);
 		if (err) {
 			hci_conn_del(acl);
 			return ERR_PTR(err);
@@ -2942,6 +2942,7 @@ int hci_abort_conn(struct hci_conn *conn, u8 reason)
 	 */
 	if (conn->state == BT_CONNECT && hdev->req_status == HCI_REQ_PEND) {
 		switch (hci_skb_event(hdev->sent_cmd)) {
+		case HCI_EV_CONN_COMPLETE:
 		case HCI_EV_LE_CONN_COMPLETE:
 		case HCI_EV_LE_ENHANCED_CONN_COMPLETE:
 		case HCI_EVT_LE_CIS_ESTABLISHED:
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 788a889210d8..e1fdcb3c2706 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -6493,13 +6493,18 @@ int hci_update_adv_data(struct hci_dev *hdev, u8 instance)
 				  UINT_PTR(instance), NULL);
 }
 
-static int __hci_acl_create_connection_sync(struct hci_dev *hdev, void *data)
+static int hci_acl_create_conn_sync(struct hci_dev *hdev, void *data)
 {
-	struct hci_conn *conn = data;
+	struct hci_conn *conn;
+	u16 handle = PTR_UINT(data);
 	struct inquiry_entry *ie;
 	struct hci_cp_create_conn cp;
 	int err;
 
+	conn = hci_conn_hash_lookup_handle(hdev, handle);
+	if (!conn)
+		return 0;
+
 	/* Many controllers disallow HCI Create Connection while it is doing
 	 * HCI Inquiry. So we cancel the Inquiry first before issuing HCI Create
 	 * Connection. This may cause the MGMT discovering state to become false
@@ -6556,9 +6561,8 @@ static int __hci_acl_create_connection_sync(struct hci_dev *hdev, void *data)
 	return err;
 }
 
-int hci_acl_create_connection_sync(struct hci_dev *hdev,
-				   struct hci_conn *conn)
+int hci_connect_acl_sync(struct hci_dev *hdev, struct hci_conn *conn)
 {
-	return hci_cmd_sync_queue(hdev, __hci_acl_create_connection_sync,
-				  conn, NULL);
+	return hci_cmd_sync_queue(hdev, hci_acl_create_conn_sync,
+				  UINT_PTR(conn->handle), NULL);
 }
-- 
2.43.0