1 files changed, 18 insertions, 9 deletions

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 73472756618a..40daa38276f3 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1411,7 +1411,8 @@ static void l2cap_request_info(struct l2cap_conn *conn)
 		       sizeof(req), &req);
 }
 
-static bool l2cap_check_enc_key_size(struct hci_conn *hcon)
+static bool l2cap_check_enc_key_size(struct hci_conn *hcon,
+				     struct l2cap_chan *chan)
 {
 	/* The minimum encryption key size needs to be enforced by the
 	 * host stack before establishing any L2CAP connections. The
@@ -1425,7 +1426,7 @@ static bool l2cap_check_enc_key_size(struct hci_conn *hcon)
 	int min_key_size = hcon->hdev->min_enc_key_size;
 
 	/* On FIPS security level, key size must be 16 bytes */
-	if (hcon->sec_level == BT_SECURITY_FIPS)
+	if (chan->sec_level == BT_SECURITY_FIPS)
 		min_key_size = 16;
 
 	return (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags) ||
@@ -1453,7 +1454,7 @@ static void l2cap_do_start(struct l2cap_chan *chan)
 	    !__l2cap_no_conn_pending(chan))
 		return;
 
-	if (l2cap_check_enc_key_size(conn->hcon))
+	if (l2cap_check_enc_key_size(conn->hcon, chan))
 		l2cap_start_connection(chan);
 	else
 		__set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
@@ -1528,7 +1529,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 				continue;
 			}
 
-			if (l2cap_check_enc_key_size(conn->hcon))
+			if (l2cap_check_enc_key_size(conn->hcon, chan))
 				l2cap_start_connection(chan);
 			else
 				l2cap_chan_close(chan, ECONNREFUSED);
@@ -3414,7 +3415,7 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data
 	struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
 	struct l2cap_conf_efs efs;
 	u8 remote_efs = 0;
-	u16 mtu = L2CAP_DEFAULT_MTU;
+	u16 mtu = 0;
 	u16 result = L2CAP_CONF_SUCCESS;
 	u16 size;
 
@@ -3519,6 +3520,13 @@ done:
 		/* Configure output options and let the other side know
 		 * which ones we don't like. */
 
+		/* If MTU is not provided in configure request, use the most recently
+		 * explicitly or implicitly accepted value for the other direction,
+		 * or the default value.
+		 */
+		if (mtu == 0)
+			mtu = chan->imtu ? chan->imtu : L2CAP_DEFAULT_MTU;
+
 		if (mtu < L2CAP_DEFAULT_MIN_MTU)
 			result = L2CAP_CONF_UNACCEPT;
 		else {
@@ -3992,7 +4000,7 @@ static void l2cap_connect(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd,
 	/* Check if the ACL is secure enough (if not SDP) */
 	if (psm != cpu_to_le16(L2CAP_PSM_SDP) &&
 	    (!hci_conn_check_link_mode(conn->hcon) ||
-	    !l2cap_check_enc_key_size(conn->hcon))) {
+	    !l2cap_check_enc_key_size(conn->hcon, pchan))) {
 		conn->disc_reason = HCI_ERROR_AUTH_FAILURE;
 		result = L2CAP_CR_SEC_BLOCK;
 		goto response;
@@ -4869,7 +4877,8 @@ static int l2cap_le_connect_req(struct l2cap_conn *conn,
 
 	if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
 				     SMP_ALLOW_STK)) {
-		result = L2CAP_CR_LE_AUTHENTICATION;
+		result = pchan->sec_level == BT_SECURITY_MEDIUM ?
+			L2CAP_CR_LE_ENCRYPTION : L2CAP_CR_LE_AUTHENTICATION;
 		chan = NULL;
 		goto response_unlock;
 	}
@@ -7352,7 +7361,7 @@ static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 		}
 
 		if (chan->state == BT_CONNECT) {
-			if (!status && l2cap_check_enc_key_size(hcon))
+			if (!status && l2cap_check_enc_key_size(hcon, chan))
 				l2cap_start_connection(chan);
 			else
 				__set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
@@ -7362,7 +7371,7 @@ static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 			struct l2cap_conn_rsp rsp;
 			__u16 res, stat;
 
-			if (!status && l2cap_check_enc_key_size(hcon)) {
+			if (!status && l2cap_check_enc_key_size(hcon, chan)) {
 				if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
 					res = L2CAP_CR_PEND;
 					stat = L2CAP_CS_AUTHOR_PEND;