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Bluetooth: Reject connection with the device which has same BD_ADDR

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This change is used to relieve CVE-2020-26555. The description of
the CVE:

Bluetooth legacy BR/EDR PIN code pairing in Bluetooth Core Specification
1.0B through 5.2 may permit an unauthenticated nearby device to spoof
the BD_ADDR of the peer device to complete pairing without knowledge
of the PIN. [1]

The detail of this attack is in IEEE paper:
BlueMirror: Reflections on Bluetooth Pairing and Provisioning Protocols
[2]

It's a reflection attack. The paper mentioned that attacker can induce
the attacked target to generate null link key (zero key) without PIN
code. In BR/EDR, the key generation is actually handled in the controller
which is below HCI.

A condition of this attack is that attacker should change the
BR_ADDR of his hacking device (Host B) to equal to the BR_ADDR with
the target device being attacked (Host A).

Thus, we reject the connection with device which has same BD_ADDR
both on HCI_Create_Connection and HCI_Connection_Request to prevent
the attack. A similar implementation also shows in btstack project.
[3][4]

Cc: stable@vger.kernel.org
Link: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26555 [1]
Link: https://ieeexplore.ieee.org/abstract/document/9474325/authors#authors [2]
Link: https://github.com/bluekitchen/btstack/blob/master/src/hci.c#L3523 [3]
Link: https://github.com/bluekitchen/btstack/blob/master/src/hci.c#L7297 [4]
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This commit is contained in:
Lee, Chun-Yi 2023-10-01 16:59:58 +08:00 committed by Luiz Augusto von Dentz
parent 33155c4aae
commit 1ffc6f8cc3
2 changed files with 20 additions and 0 deletions
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9
net/bluetooth/hci_conn.c
View File

@ -1627,6 +1627,15 @@ struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
return ERR_PTR(-EOPNOTSUPP);
}
/* Reject outgoing connection to device with same BD ADDR against
* CVE-2020-26555
*/
if (!bacmp(&hdev->bdaddr, dst)) {
bt_dev_dbg(hdev, "Reject connection with same BD_ADDR %pMR\n",
dst);
return ERR_PTR(-ECONNREFUSED);
}
acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
if (!acl) {
acl = hci_conn_add(hdev, ACL_LINK, dst, HCI_ROLE_MASTER);

11
net/bluetooth/hci_event.c
View File

@ -3268,6 +3268,17 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
bt_dev_dbg(hdev, "bdaddr %pMR type 0x%x", &ev->bdaddr, ev->link_type);
/* Reject incoming connection from device with same BD ADDR against
* CVE-2020-26555
*/
if (!bacmp(&hdev->bdaddr, &ev->bdaddr))
{
bt_dev_dbg(hdev, "Reject connection with same BD_ADDR %pMR\n",
&ev->bdaddr);
hci_reject_conn(hdev, &ev->bdaddr);
return;
}
mask |= hci_proto_connect_ind(hdev, &ev->bdaddr, ev->link_type,
&flags);