| Message ID | 20231001081106.GA14555@linux-691t (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Bluetooth: ignore NULL link key and reject connection with the device which has same BD_ADDR | expand |
| Context | Check | Description |
|---|---|---|
| tedd_an/pre-ci_am | success | Success |
| tedd_an/CheckPatch | fail | ERROR: that open brace { should be on the previous line #144: FILE: net/bluetooth/hci_conn.c:1615: + if (!bacmp(&hdev->bdaddr, dst)) + { ERROR: that open brace { should be on the previous line #162: FILE: net/bluetooth/hci_event.c:3272: + if (!bacmp(&hdev->bdaddr, &ev->bdaddr)) + { WARNING: line length of 108 exceeds 100 columns #164: FILE: net/bluetooth/hci_event.c:3274: + bt_dev_dbg(hdev, "Reject connection from the device with same BD_ADDR %pMR\n", &ev->bdaddr); total: 2 errors, 1 warnings, 0 checks, 27 lines checked NOTE: For some of the reported defects, checkpatch may be able to mechanically convert to the typical style using --fix or --fix-inplace. /github/workspace/src/src/13405302.patch has style problems, please review. NOTE: Ignored message types: UNKNOWN_COMMIT_ID NOTE: If any of the errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. |
| tedd_an/GitLint | success | Gitlint PASS |
| tedd_an/SubjectPrefix | success | Gitlint PASS |
| tedd_an/IncrementalBuild | success | Incremental Build PASS |
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index 056f9516e46d..583d2e18314e 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -1611,6 +1611,13 @@ 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 to the device 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); diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index a20a94e85b1a..d66718190dc5 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -3268,6 +3268,14 @@ 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 from the device 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);
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] 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> --- net/bluetooth/hci_conn.c | 7 +++++++ net/bluetooth/hci_event.c | 8 ++++++++ 2 files changed, 15 insertions(+)