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authorMarcel Holtmann <marcel@holtmann.org>2008-09-09 07:19:20 +0200
committerMarcel Holtmann <marcel@holtmann.org>2008-09-09 07:19:20 +0200
commite7c29cb16c833441fd2160642bb13025f4e7ac70 (patch)
tree7ba44be60b7bf9c4e7bee459735ebabdc85eb8fd
parent09ab6f4c2376a0fc31abde1e2991513f900ea825 (diff)
[Bluetooth] Reject L2CAP connections on an insecure ACL link
The Security Mode 4 of the Bluetooth 2.1 specification has strict authentication and encryption requirements. It is the initiators job to create a secure ACL link. However in case of malicious devices, the acceptor has to make sure that the ACL is encrypted before allowing any kind of L2CAP connection. The only exception here is the PSM 1 for the service discovery protocol, because that is allowed to run on an insecure ACL link. Previously it was enough to reject a L2CAP connection during the connection setup phase, but with Bluetooth 2.1 it is forbidden to do any L2CAP protocol exchange on an insecure link (except SDP). The new hci_conn_check_link_mode() function can be used to check the integrity of an ACL link. This functions also takes care of the cases where Security Mode 4 is disabled or one of the devices is based on an older specification. Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
-rw-r--r--include/net/bluetooth/hci_core.h1
-rw-r--r--net/bluetooth/af_bluetooth.c2
-rw-r--r--net/bluetooth/hci_conn.c13
-rw-r--r--net/bluetooth/l2cap.c15
4 files changed, 26 insertions, 5 deletions
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 5e785b968e7e..46a43b721dd6 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -326,6 +326,7 @@ void hci_conn_hash_flush(struct hci_dev *hdev);
void hci_conn_check_pending(struct hci_dev *hdev);
struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8 auth_type);
+int hci_conn_check_link_mode(struct hci_conn *conn);
int hci_conn_auth(struct hci_conn *conn);
int hci_conn_encrypt(struct hci_conn *conn);
int hci_conn_change_link_key(struct hci_conn *conn);
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index 1edfdf4c095b..f6348e078aa4 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -49,7 +49,7 @@
#define BT_DBG(D...)
#endif
-#define VERSION "2.12"
+#define VERSION "2.13"
/* Bluetooth sockets */
#define BT_MAX_PROTO 8
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index a2f9efaa3361..b7002429f152 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -376,6 +376,19 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8
}
EXPORT_SYMBOL(hci_connect);
+/* Check link security requirement */
+int hci_conn_check_link_mode(struct hci_conn *conn)
+{
+ BT_DBG("conn %p", conn);
+
+ if (conn->ssp_mode > 0 && conn->hdev->ssp_mode > 0 &&
+ !(conn->link_mode & HCI_LM_ENCRYPT))
+ return 0;
+
+ return 1;
+}
+EXPORT_SYMBOL(hci_conn_check_link_mode);
+
/* Authenticate remote device */
int hci_conn_auth(struct hci_conn *conn)
{
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index a96d6de80d12..9610a9c85b98 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1568,10 +1568,10 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
struct l2cap_conn_req *req = (struct l2cap_conn_req *) data;
struct l2cap_conn_rsp rsp;
struct sock *sk, *parent;
- int result, status = 0;
+ int result, status = L2CAP_CS_NO_INFO;
u16 dcid = 0, scid = __le16_to_cpu(req->scid);
- __le16 psm = req->psm;
+ __le16 psm = req->psm;
BT_DBG("psm 0x%2.2x scid 0x%4.4x", psm, scid);
@@ -1582,6 +1582,13 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
goto sendresp;
}
+ /* Check if the ACL is secure enough (if not SDP) */
+ if (psm != cpu_to_le16(0x0001) &&
+ !hci_conn_check_link_mode(conn->hcon)) {
+ result = L2CAP_CR_SEC_BLOCK;
+ goto response;
+ }
+
result = L2CAP_CR_NO_MEM;
/* Check for backlog size */
@@ -2239,7 +2246,7 @@ static int l2cap_auth_cfm(struct hci_conn *hcon, u8 status)
rsp.scid = cpu_to_le16(l2cap_pi(sk)->dcid);
rsp.dcid = cpu_to_le16(l2cap_pi(sk)->scid);
rsp.result = cpu_to_le16(result);
- rsp.status = cpu_to_le16(0);
+ rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
L2CAP_CONN_RSP, sizeof(rsp), &rsp);
}
@@ -2311,7 +2318,7 @@ static int l2cap_encrypt_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
rsp.scid = cpu_to_le16(l2cap_pi(sk)->dcid);
rsp.dcid = cpu_to_le16(l2cap_pi(sk)->scid);
rsp.result = cpu_to_le16(result);
- rsp.status = cpu_to_le16(0);
+ rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
L2CAP_CONN_RSP, sizeof(rsp), &rsp);
}

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