* [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key
2023-10-01 8:49 [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection with the device which has same BD_ADDR Lee, Chun-Yi
@ 2023-10-01 8:53 ` Lee, Chun-Yi
2023-10-01 8:54 ` [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR Lee, Chun-Yi
` (2 subsequent siblings)
3 siblings, 0 replies; 7+ messages in thread
From: Lee, Chun-Yi @ 2023-10-01 8:53 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 35f251041eeb..2830abbdd329 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4741,6 +4741,14 @@ 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] 7+ 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 connection with the device which has same BD_ADDR Lee, Chun-Yi
2023-10-01 8:53 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
@ 2023-10-01 8:54 ` Lee, Chun-Yi
2023-10-01 8:59 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
2023-10-01 8:59 ` [PATCH 2/2] Bluetooth: Reject " Lee, Chun-Yi
3 siblings, 0 replies; 7+ 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] 7+ messages in thread* [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key
2023-10-01 8:49 [PATCH 0/2] Bluetooth: ignore NULL link key and reject connection with the device which has same BD_ADDR Lee, Chun-Yi
2023-10-01 8:53 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
2023-10-01 8:54 ` [PATCH 2/2] Bluetooth: Reject connection with the device which has same BD_ADDR Lee, Chun-Yi
@ 2023-10-01 8:59 ` Lee, Chun-Yi
2023-10-01 9:37 ` Bluetooth: ignore NULL link key and reject connection with the device which has same BD_ADDR bluez.test.bot
2023-10-01 8:59 ` [PATCH 2/2] Bluetooth: Reject " Lee, Chun-Yi
3 siblings, 1 reply; 7+ 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.
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 35f251041eeb..2830abbdd329 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4741,6 +4741,14 @@ 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] 7+ messages in thread* RE: Bluetooth: ignore NULL link key and reject connection with the device which has same BD_ADDR
2023-10-01 8:59 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
@ 2023-10-01 9:37 ` bluez.test.bot
0 siblings, 0 replies; 7+ messages in thread
From: bluez.test.bot @ 2023-10-01 9:37 UTC (permalink / raw)
To: linux-bluetooth, jlee
[-- Attachment #1: Type: text/plain, Size: 3111 bytes --]
This is automated email and please do not reply to this email!
Dear submitter,
Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=789101
---Test result---
Test Summary:
CheckPatch FAIL 2.89 seconds
GitLint PASS 0.61 seconds
SubjectPrefix PASS 0.20 seconds
BuildKernel PASS 35.46 seconds
CheckAllWarning PASS 39.10 seconds
CheckSparse WARNING 44.54 seconds
CheckSmatch WARNING 118.36 seconds
BuildKernel32 PASS 34.21 seconds
TestRunnerSetup PASS 520.60 seconds
TestRunner_l2cap-tester PASS 32.09 seconds
TestRunner_iso-tester PASS 55.24 seconds
TestRunner_bnep-tester PASS 10.58 seconds
TestRunner_mgmt-tester PASS 234.69 seconds
TestRunner_rfcomm-tester PASS 16.34 seconds
TestRunner_sco-tester PASS 19.67 seconds
TestRunner_ioctl-tester PASS 18.91 seconds
TestRunner_mesh-tester PASS 13.78 seconds
TestRunner_smp-tester PASS 14.59 seconds
TestRunner_userchan-tester PASS 11.30 seconds
IncrementalBuild PASS 39.54 seconds
Details
##############################
Test: CheckPatch - FAIL
Desc: Run checkpatch.pl script
Output:
[2/2] Bluetooth: Reject connection with the device which has same BD_ADDR
ERROR: that open brace { should be on the previous line
#144: FILE: net/bluetooth/hci_conn.c:1631:
+ if (!bacmp(&hdev->bdaddr, dst))
+ {
ERROR: that open brace { should be on the previous line
#162: FILE: net/bluetooth/hci_event.c:3271:
+ if (!bacmp(&hdev->bdaddr, &ev->bdaddr))
+ {
WARNING: line length of 108 exceeds 100 columns
#164: FILE: net/bluetooth/hci_event.c:3273:
+ 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/13405332.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.
##############################
Test: CheckSparse - WARNING
Desc: Run sparse tool with linux kernel
Output:
net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h):net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h):
##############################
Test: CheckSmatch - WARNING
Desc: Run smatch tool with source
Output:
net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h):net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h):
---
Regards,
Linux Bluetooth
^ permalink raw reply [flat|nested] 7+ 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 connection with the device which has same BD_ADDR Lee, Chun-Yi
` (2 preceding siblings ...)
2023-10-01 8:59 ` [PATCH 1/2] Bluetooth: hci_event: Ignore NULL link key Lee, Chun-Yi
@ 2023-10-01 8:59 ` Lee, Chun-Yi
3 siblings, 0 replies; 7+ 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] 7+ messages in thread