bluetooth/hci: disallow setting handle bigger than HCI_CONN_HANDLE_MAX

Syzbot hit warning in hci_conn_del() caused by freeing handle that was
not allocated using ida allocator.

This is caused by handle bigger than HCI_CONN_HANDLE_MAX passed by
hci_le_big_sync_established_evt(), which makes code think it's unset
connection.

Add same check for handle upper bound as in hci_conn_set_handle() to
prevent warning.

Link: https://syzkaller.appspot.com/bug?extid=b2545b087a01a7319474
Reported-by: syzbot+b2545b087a01a7319474@syzkaller.appspotmail.com
Fixes: 181a42edddf5 ("Bluetooth: Make handle of hci_conn be unique")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 0c76dcde53619627cdb4544b36b02a8bfc8cc936..080053a85b4d69a13afeb483cdda136704a8fc36 100644 (file)
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -899,8 +899,8 @@ static int hci_conn_hash_alloc_unset(struct hci_dev *hdev)
                               U16_MAX, GFP_ATOMIC);
 }
 
-struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
-                             u8 role, u16 handle)
+static struct hci_conn *__hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
+                                      u8 role, u16 handle)
 {
        struct hci_conn *conn;
 
@@ -1041,7 +1041,16 @@ struct hci_conn *hci_conn_add_unset(struct hci_dev *hdev, int type,
        if (unlikely(handle < 0))
                return ERR_PTR(-ECONNREFUSED);
 
-       return hci_conn_add(hdev, type, dst, role, handle);
+       return __hci_conn_add(hdev, type, dst, role, handle);
+}
+
+struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
+                             u8 role, u16 handle)
+{
+       if (handle > HCI_CONN_HANDLE_MAX)
+               return ERR_PTR(-EINVAL);
+
+       return __hci_conn_add(hdev, type, dst, role, handle);
 }
 
 static void hci_conn_cleanup_child(struct hci_conn *conn, u8 reason)