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* [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection
@ 2023-10-01  7:45 Lee, Chun-Yi
  2023-10-01  7:48 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
                   ` (4 more replies)
  0 siblings, 5 replies; 9+ messages in thread
From: Lee, Chun-Yi @ 2023-10-01  7:45 UTC (permalink / raw)
  To: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz
  Cc: linux-kernel, linux-bluetooth

with the device which has same BD_ADDR
 
This patch set 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.

Thus, we can ignore null link key in the handler of "Link Key Notification
event" to relieve the attack. And, 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). So we reject
the connection with device which has same BD_ADDR both on HCI_Create_Connection
and HCI_Connection_Request to prevent the attack.

Similar implementations also show in btstack project. [3][4][5]

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#L3722 [3]
Link: https://github.com/bluekitchen/btstack/blob/master/src/hci.c#L3523 [4]
Link: https://github.com/bluekitchen/btstack/blob/master/src/hci.c#L7297 [5]

Lee, Chun-Yi (2):
  Bluetooth: hci_event: Ignore NULL link key
  Bluetooth: Reject connection with the device which has same BD_ADDR

 net/bluetooth/hci_conn.c  |  7 +++++++
 net/bluetooth/hci_event.c | 16 ++++++++++++++++
 2 files changed, 23 insertions(+)

-- 
2.35.3

From 2c6cd3f353d21086a3163a9ad461789d203a7ee4 Mon Sep 17 00:00:00 2001
From: "Lee, Chun-Yi" <jlee@suse.com>
Date: Sat, 30 Sep 2023 16:56:56 +0800
Subject: [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection 
with the device which has same BD_ADDR
 
This patch set 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.

Thus, we can ignore null link key in the handler of "Link Key Notification
event" to relieve the attack. And, 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). So we reject
the connection with device which has same BD_ADDR both on HCI_Create_Connection
and HCI_Connection_Request to prevent the attack.

Similar implementations also show in btstack project. [3][4][5]

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#L3722 [3]
Link: https://github.com/bluekitchen/btstack/blob/master/src/hci.c#L3523 [4]
Link: https://github.com/bluekitchen/btstack/blob/master/src/hci.c#L7297 [5]

Lee, Chun-Yi (2):
  Bluetooth: hci_event: Ignore NULL link key
  Bluetooth: Reject connection with the device which has same BD_ADDR

 net/bluetooth/hci_conn.c  |  7 +++++++
 net/bluetooth/hci_event.c | 16 ++++++++++++++++
 2 files changed, 23 insertions(+)

-- 
2.35.3


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key
  2023-10-01  7:45 [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection Lee, Chun-Yi
@ 2023-10-01  7:48 ` Lee, Chun-Yi
  2023-10-01  7:48 ` [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR Lee, Chun-Yi
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 9+ messages in thread
From: Lee, Chun-Yi @ 2023-10-01  7:48 UTC (permalink / raw)
  To: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz
  Cc: linux-kernel, linux-bluetooth

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.

Thus, we can ignore null link key in the handler of "Link Key Notification
event" to relieve the attack. A similar implementation also shows in
btstack project. [3]

v3: Drop the connection when null link key be detected.

v2:
- Used Link: tag instead of Closes:
- Used bt_dev_dbg instead of BT_DBG
- Added Fixes: tag

Fixes: 55ed8ca10f35 ("Bluetooth: Implement link key handling for the management interface")
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#L3722 [3]
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
---
 net/bluetooth/hci_event.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 95816a938cea..a20a94e85b1a 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4692,6 +4692,14 @@ static void hci_link_key_notify_evt(struct hci_dev *hdev, void *data,
 	if (!conn)
 		goto unlock;
 
+	/* Ignore NULL link key against CVE-2020-26555 */
+	if (!memcmp(ev->link_key, ZERO_KEY, HCI_LINK_KEY_SIZE)) {
+		bt_dev_dbg(hdev, "Ignore NULL link key (ZERO KEY) for %pMR", &ev->bdaddr);
+		hci_disconnect(conn, HCI_ERROR_AUTH_FAILURE);
+		hci_conn_drop(conn);
+		goto unlock;
+	}
+
 	hci_conn_hold(conn);
 	conn->disc_timeout = HCI_DISCONN_TIMEOUT;
 	hci_conn_drop(conn);
-- 
2.35.3

From 5fed42878147cffa22e695732d87a85c218d217f Mon Sep 17 00:00:00 2001
From: "Lee, Chun-Yi" <jlee@suse.com>
Date: Fri, 14 Jul 2023 21:14:01 +0800
Subject: [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key
In-Reply-To: <20231001074524.GA14361@linux-691t>
References: <20231001074524.GA14361@linux-691t>

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.

Thus, we can ignore null link key in the handler of "Link Key Notification
event" to relieve the attack. A similar implementation also shows in
btstack project. [3]

v3: Drop the connection when null link key be detected.

v2:
- Used Link: tag instead of Closes:
- Used bt_dev_dbg instead of BT_DBG
- Added Fixes: tag

Fixes: 55ed8ca10f35 ("Bluetooth: Implement link key handling for the management interface")
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#L3722 [3]
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
---
 net/bluetooth/hci_event.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 95816a938cea..a20a94e85b1a 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4692,6 +4692,14 @@ static void hci_link_key_notify_evt(struct hci_dev *hdev, void *data,
 	if (!conn)
 		goto unlock;
 
+	/* Ignore NULL link key against CVE-2020-26555 */
+	if (!memcmp(ev->link_key, ZERO_KEY, HCI_LINK_KEY_SIZE)) {
+		bt_dev_dbg(hdev, "Ignore NULL link key (ZERO KEY) for %pMR", &ev->bdaddr);
+		hci_disconnect(conn, HCI_ERROR_AUTH_FAILURE);
+		hci_conn_drop(conn);
+		goto unlock;
+	}
+
 	hci_conn_hold(conn);
 	conn->disc_timeout = HCI_DISCONN_TIMEOUT;
 	hci_conn_drop(conn);
-- 
2.35.3


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR
  2023-10-01  7:45 [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection Lee, Chun-Yi
  2023-10-01  7:48 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
@ 2023-10-01  7:48 ` Lee, Chun-Yi
  2023-10-01  8:05 ` [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection joeyli
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 9+ messages in thread
From: Lee, Chun-Yi @ 2023-10-01  7:48 UTC (permalink / raw)
  To: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz
  Cc: linux-kernel, linux-bluetooth

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(+)

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);
 
-- 
2.35.3

From 2c6cd3f353d21086a3163a9ad461789d203a7ee4 Mon Sep 17 00:00:00 2001
From: "Lee, Chun-Yi" <jlee@suse.com>
Date: Wed, 16 Aug 2023 21:03:06 +0800
Subject: [PATCH 2/2] Bluetooth: Reject connection with the device which has
 same BD_ADDR
In-Reply-To: <20231001074524.GA14361@linux-691t>
References: <20231001074524.GA14361@linux-691t>

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(+)

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);
 
-- 
2.35.3


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection
  2023-10-01  7:45 [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection Lee, Chun-Yi
  2023-10-01  7:48 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
  2023-10-01  7:48 ` [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR Lee, Chun-Yi
@ 2023-10-01  8:05 ` joeyli
  2023-10-01  8:08 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
  2023-10-01  8:09 ` [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR Lee, Chun-Yi
  4 siblings, 0 replies; 9+ messages in thread
From: joeyli @ 2023-10-01  8:05 UTC (permalink / raw)
  To: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz
  Cc: linux-kernel, linux-bluetooth

Hi experts,

On Sun, Oct 01, 2023 at 03:45:24PM +0800, Lee, Chun-Yi wrote:
> with the device which has same BD_ADDR
>  
> This patch set 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.
> 
> Thus, we can ignore null link key in the handler of "Link Key Notification
> event" to relieve the attack. And, 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). So we reject
> the connection with device which has same BD_ADDR both on HCI_Create_Connection
> and HCI_Connection_Request to prevent the attack.
> 
> Similar implementations also show in btstack project. [3][4][5]
> 
> 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#L3722 [3]
> Link: https://github.com/bluekitchen/btstack/blob/master/src/hci.c#L3523 [4]
> Link: https://github.com/bluekitchen/btstack/blob/master/src/hci.c#L7297 [5]
> 
> Lee, Chun-Yi (2):
>   Bluetooth: hci_event: Ignore NULL link key
>   Bluetooth: Reject connection with the device which has same BD_ADDR
> 
>  net/bluetooth/hci_conn.c  |  7 +++++++
>  net/bluetooth/hci_event.c | 16 ++++++++++++++++
>  2 files changed, 23 insertions(+)
> 
> -- 
> 2.35.3
> 
> >From 2c6cd3f353d21086a3163a9ad461789d203a7ee4 Mon Sep 17 00:00:00 2001
> From: "Lee, Chun-Yi" <jlee@suse.com>
> Date: Sat, 30 Sep 2023 16:56:56 +0800
> Subject: [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection 
> with the device which has same BD_ADDR
>  

Please ignore this patch set because I used wrong mutt command to send out
patch. It causes that the mail has duplicate contents. I will send out a
new series.

Sorry for any inconvenience caused!

Joey Lee

> This patch set 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.
> 
> Thus, we can ignore null link key in the handler of "Link Key Notification
> event" to relieve the attack. And, 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). So we reject
> the connection with device which has same BD_ADDR both on HCI_Create_Connection
> and HCI_Connection_Request to prevent the attack.
> 
> Similar implementations also show in btstack project. [3][4][5]
> 
> 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#L3722 [3]
> Link: https://github.com/bluekitchen/btstack/blob/master/src/hci.c#L3523 [4]
> Link: https://github.com/bluekitchen/btstack/blob/master/src/hci.c#L7297 [5]
> 
> Lee, Chun-Yi (2):
>   Bluetooth: hci_event: Ignore NULL link key
>   Bluetooth: Reject connection with the device which has same BD_ADDR
> 
>  net/bluetooth/hci_conn.c  |  7 +++++++
>  net/bluetooth/hci_event.c | 16 ++++++++++++++++
>  2 files changed, 23 insertions(+)
> 
> -- 
> 2.35.3

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key
  2023-10-01  7:45 [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection Lee, Chun-Yi
                   ` (2 preceding siblings ...)
  2023-10-01  8:05 ` [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection joeyli
@ 2023-10-01  8:08 ` Lee, Chun-Yi
  2023-10-01  8:09 ` [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR Lee, Chun-Yi
  4 siblings, 0 replies; 9+ messages in thread
From: Lee, Chun-Yi @ 2023-10-01  8:08 UTC (permalink / raw)
  To: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz
  Cc: linux-kernel, linux-bluetooth

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.

Thus, we can ignore null link key in the handler of "Link Key Notification
event" to relieve the attack. A similar implementation also shows in
btstack project. [3]

v3: Drop the connection when null link key be detected.

v2:
- Used Link: tag instead of Closes:
- Used bt_dev_dbg instead of BT_DBG
- Added Fixes: tag

Fixes: 55ed8ca10f35 ("Bluetooth: Implement link key handling for the management interface")
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#L3722 [3]
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
---
 net/bluetooth/hci_event.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 95816a938cea..a20a94e85b1a 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4692,6 +4692,14 @@ static void hci_link_key_notify_evt(struct hci_dev *hdev, void *data,
 	if (!conn)
 		goto unlock;
 
+	/* Ignore NULL link key against CVE-2020-26555 */
+	if (!memcmp(ev->link_key, ZERO_KEY, HCI_LINK_KEY_SIZE)) {
+		bt_dev_dbg(hdev, "Ignore NULL link key (ZERO KEY) for %pMR", &ev->bdaddr);
+		hci_disconnect(conn, HCI_ERROR_AUTH_FAILURE);
+		hci_conn_drop(conn);
+		goto unlock;
+	}
+
 	hci_conn_hold(conn);
 	conn->disc_timeout = HCI_DISCONN_TIMEOUT;
 	hci_conn_drop(conn);
-- 
2.35.3


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR
  2023-10-01  7:45 [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection Lee, Chun-Yi
                   ` (3 preceding siblings ...)
  2023-10-01  8:08 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
@ 2023-10-01  8:09 ` Lee, Chun-Yi
  4 siblings, 0 replies; 9+ messages in thread
From: Lee, Chun-Yi @ 2023-10-01  8:09 UTC (permalink / raw)
  To: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz
  Cc: linux-kernel, linux-bluetooth

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(+)

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);
 
-- 
2.35.3


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR
  2023-10-01  8:03 [PATCH 0/2] Bluetooth: ignore NULL link key and reject " Lee, Chun-Yi
@ 2023-10-01  8:11 ` Lee, Chun-Yi
  0 siblings, 0 replies; 9+ messages in thread
From: Lee, Chun-Yi @ 2023-10-01  8:11 UTC (permalink / raw)
  To: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz
  Cc: linux-kernel, linux-bluetooth

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(+)

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);
 
-- 
2.35.3


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR
  2023-10-01  8:49 [PATCH 0/2] Bluetooth: ignore NULL link key and reject " Lee, Chun-Yi
@ 2023-10-01  8:54 ` Lee, Chun-Yi
  2023-10-01  8:59 ` Lee, Chun-Yi
  1 sibling, 0 replies; 9+ messages in thread
From: Lee, Chun-Yi @ 2023-10-01  8:54 UTC (permalink / raw)
  To: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz
  Cc: linux-kernel, linux-bluetooth

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(+)

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 9d5057cef30a..21c831f1fec6 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1627,6 +1627,13 @@ 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 2830abbdd329..df97dd64be6a 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3267,6 +3267,14 @@ 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);
 
-- 
2.35.3


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR
  2023-10-01  8:49 [PATCH 0/2] Bluetooth: ignore NULL link key and reject " Lee, Chun-Yi
  2023-10-01  8:54 ` [PATCH 2/2] Bluetooth: Reject " Lee, Chun-Yi
@ 2023-10-01  8:59 ` Lee, Chun-Yi
  1 sibling, 0 replies; 9+ messages in thread
From: Lee, Chun-Yi @ 2023-10-01  8:59 UTC (permalink / raw)
  To: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz
  Cc: linux-kernel, linux-bluetooth

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(+)

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 9d5057cef30a..21c831f1fec6 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1627,6 +1627,13 @@ 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 2830abbdd329..df97dd64be6a 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3267,6 +3267,14 @@ 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);
 
-- 
2.35.3


^ permalink raw reply related	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2023-10-01  9:00 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-10-01  7:45 [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection Lee, Chun-Yi
2023-10-01  7:48 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
2023-10-01  7:48 ` [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR Lee, Chun-Yi
2023-10-01  8:05 ` [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection joeyli
2023-10-01  8:08 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
2023-10-01  8:09 ` [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR Lee, Chun-Yi
  -- strict thread matches above, loose matches on Subject: below --
2023-10-01  8:03 [PATCH 0/2] Bluetooth: ignore NULL link key and reject " Lee, Chun-Yi
2023-10-01  8:11 ` [PATCH 2/2] Bluetooth: Reject " Lee, Chun-Yi
2023-10-01  8:49 [PATCH 0/2] Bluetooth: ignore NULL link key and reject " Lee, Chun-Yi
2023-10-01  8:54 ` [PATCH 2/2] Bluetooth: Reject " Lee, Chun-Yi
2023-10-01  8:59 ` Lee, Chun-Yi

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