1 files changed, 79 insertions, 88 deletions

diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index b23e2713fea8..ca957d34b0c8 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -69,7 +69,7 @@ static struct rfcomm_session *rfcomm_session_create(bdaddr_t *src,
 							u8 sec_level,
 							int *err);
 static struct rfcomm_session *rfcomm_session_get(bdaddr_t *src, bdaddr_t *dst);
-static void rfcomm_session_del(struct rfcomm_session *s);
+static struct rfcomm_session *rfcomm_session_del(struct rfcomm_session *s);
 
 /* ---- RFCOMM frame parsing macros ---- */
 #define __get_dlci(b)     ((b & 0xfc) >> 2)
@@ -108,12 +108,6 @@ static void rfcomm_schedule(void)
 	wake_up_process(rfcomm_thread);
 }
 
-static void rfcomm_session_put(struct rfcomm_session *s)
-{
-	if (atomic_dec_and_test(&s->refcnt))
-		rfcomm_session_del(s);
-}
-
 /* ---- RFCOMM FCS computation ---- */
 
 /* reversed, 8-bit, poly=0x07 */
@@ -249,16 +243,14 @@ static void rfcomm_session_set_timer(struct rfcomm_session *s, long timeout)
 {
 	BT_DBG("session %p state %ld timeout %ld", s, s->state, timeout);
 
-	if (!mod_timer(&s->timer, jiffies + timeout))
-		rfcomm_session_hold(s);
+	mod_timer(&s->timer, jiffies + timeout);
 }
 
 static void rfcomm_session_clear_timer(struct rfcomm_session *s)
 {
 	BT_DBG("session %p state %ld", s, s->state);
 
-	if (del_timer(&s->timer))
-		rfcomm_session_put(s);
+	del_timer_sync(&s->timer);
 }
 
 /* ---- RFCOMM DLCs ---- */
@@ -336,8 +328,6 @@ static void rfcomm_dlc_link(struct rfcomm_session *s, struct rfcomm_dlc *d)
 {
 	BT_DBG("dlc %p session %p", d, s);
 
-	rfcomm_session_hold(s);
-
 	rfcomm_session_clear_timer(s);
 	rfcomm_dlc_hold(d);
 	list_add(&d->list, &s->dlcs);
@@ -356,8 +346,6 @@ static void rfcomm_dlc_unlink(struct rfcomm_dlc *d)
 
 	if (list_empty(&s->dlcs))
 		rfcomm_session_set_timer(s, RFCOMM_IDLE_TIMEOUT);
-
-	rfcomm_session_put(s);
 }
 
 static struct rfcomm_dlc *rfcomm_dlc_get(struct rfcomm_session *s, u8 dlci)
@@ -493,12 +481,34 @@ static int __rfcomm_dlc_close(struct rfcomm_dlc *d, int err)
 
 int rfcomm_dlc_close(struct rfcomm_dlc *d, int err)
 {
-	int r;
+	int r = 0;
+	struct rfcomm_dlc *d_list;
+	struct rfcomm_session *s, *s_list;
+
+	BT_DBG("dlc %p state %ld dlci %d err %d", d, d->state, d->dlci, err);
 
 	rfcomm_lock();
 
-	r = __rfcomm_dlc_close(d, err);
+	s = d->session;
+	if (!s)
+		goto no_session;
+
+	/* after waiting on the mutex check the session still exists
+	 * then check the dlc still exists
+	 */
+	list_for_each_entry(s_list, &session_list, list) {
+		if (s_list == s) {
+			list_for_each_entry(d_list, &s->dlcs, list) {
+				if (d_list == d) {
+					r = __rfcomm_dlc_close(d, err);
+					break;
+				}
+			}
+			break;
+		}
+	}
 
+no_session:
 	rfcomm_unlock();
 	return r;
 }
@@ -609,7 +619,7 @@ static struct rfcomm_session *rfcomm_session_add(struct socket *sock, int state)
 	return s;
 }
 
-static void rfcomm_session_del(struct rfcomm_session *s)
+static struct rfcomm_session *rfcomm_session_del(struct rfcomm_session *s)
 {
 	int state = s->state;
 
@@ -617,15 +627,14 @@ static void rfcomm_session_del(struct rfcomm_session *s)
 
 	list_del(&s->list);
 
-	if (state == BT_CONNECTED)
-		rfcomm_send_disc(s, 0);
-
 	rfcomm_session_clear_timer(s);
 	sock_release(s->sock);
 	kfree(s);
 
 	if (state != BT_LISTEN)
 		module_put(THIS_MODULE);
+
+	return NULL;
 }
 
 static struct rfcomm_session *rfcomm_session_get(bdaddr_t *src, bdaddr_t *dst)
@@ -644,17 +653,16 @@ static struct rfcomm_session *rfcomm_session_get(bdaddr_t *src, bdaddr_t *dst)
 	return NULL;
 }
 
-static void rfcomm_session_close(struct rfcomm_session *s, int err)
+static struct rfcomm_session *rfcomm_session_close(struct rfcomm_session *s,
+						   int err)
 {
 	struct rfcomm_dlc *d;
 	struct list_head *p, *n;
 
-	BT_DBG("session %p state %ld err %d", s, s->state, err);
-
-	rfcomm_session_hold(s);
-
 	s->state = BT_CLOSED;
 
+	BT_DBG("session %p state %ld err %d", s, s->state, err);
+
 	/* Close all dlcs */
 	list_for_each_safe(p, n, &s->dlcs) {
 		d = list_entry(p, struct rfcomm_dlc, list);
@@ -663,7 +671,7 @@ static void rfcomm_session_close(struct rfcomm_session *s, int err)
 	}
 
 	rfcomm_session_clear_timer(s);
-	rfcomm_session_put(s);
+	return rfcomm_session_del(s);
 }
 
 static struct rfcomm_session *rfcomm_session_create(bdaddr_t *src,
@@ -715,8 +723,7 @@ static struct rfcomm_session *rfcomm_session_create(bdaddr_t *src,
 	if (*err == 0 || *err == -EINPROGRESS)
 		return s;
 
-	rfcomm_session_del(s);
-	return NULL;
+	return rfcomm_session_del(s);
 
 failed:
 	sock_release(sock);
@@ -1105,7 +1112,7 @@ static void rfcomm_make_uih(struct sk_buff *skb, u8 addr)
 }
 
 /* ---- RFCOMM frame reception ---- */
-static int rfcomm_recv_ua(struct rfcomm_session *s, u8 dlci)
+static struct rfcomm_session *rfcomm_recv_ua(struct rfcomm_session *s, u8 dlci)
 {
 	BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
 
@@ -1114,7 +1121,7 @@ static int rfcomm_recv_ua(struct rfcomm_session *s, u8 dlci)
 		struct rfcomm_dlc *d = rfcomm_dlc_get(s, dlci);
 		if (!d) {
 			rfcomm_send_dm(s, dlci);
-			return 0;
+			return s;
 		}
 
 		switch (d->state) {
@@ -1150,25 +1157,14 @@ static int rfcomm_recv_ua(struct rfcomm_session *s, u8 dlci)
 			break;
 
 		case BT_DISCONN:
-			/* rfcomm_session_put is called later so don't do
-			 * anything here otherwise we will mess up the session
-			 * reference counter:
-			 *
-			 * (a) when we are the initiator dlc_unlink will drive
-			 * the reference counter to 0 (there is no initial put
-			 * after session_add)
-			 *
-			 * (b) when we are not the initiator rfcomm_rx_process
-			 * will explicitly call put to balance the initial hold
-			 * done after session add.
-			 */
+			s = rfcomm_session_close(s, ECONNRESET);
 			break;
 		}
 	}
-	return 0;
+	return s;
 }
 
-static int rfcomm_recv_dm(struct rfcomm_session *s, u8 dlci)
+static struct rfcomm_session *rfcomm_recv_dm(struct rfcomm_session *s, u8 dlci)
 {
 	int err = 0;
 
@@ -1192,13 +1188,13 @@ static int rfcomm_recv_dm(struct rfcomm_session *s, u8 dlci)
 		else
 			err = ECONNRESET;
 
-		s->state = BT_CLOSED;
-		rfcomm_session_close(s, err);
+		s = rfcomm_session_close(s, err);
 	}
-	return 0;
+	return s;
 }
 
-static int rfcomm_recv_disc(struct rfcomm_session *s, u8 dlci)
+static struct rfcomm_session *rfcomm_recv_disc(struct rfcomm_session *s,
+					       u8 dlci)
 {
 	int err = 0;
 
@@ -1227,11 +1223,9 @@ static int rfcomm_recv_disc(struct rfcomm_session *s, u8 dlci)
 		else
 			err = ECONNRESET;
 
-		s->state = BT_CLOSED;
-		rfcomm_session_close(s, err);
+		s = rfcomm_session_close(s, err);
 	}
-
-	return 0;
+	return s;
 }
 
 void rfcomm_dlc_accept(struct rfcomm_dlc *d)
@@ -1652,11 +1646,18 @@ drop:
 	return 0;
 }
 
-static int rfcomm_recv_frame(struct rfcomm_session *s, struct sk_buff *skb)
+static struct rfcomm_session *rfcomm_recv_frame(struct rfcomm_session *s,
+						struct sk_buff *skb)
 {
 	struct rfcomm_hdr *hdr = (void *) skb->data;
 	u8 type, dlci, fcs;
 
+	if (!s) {
+		/* no session, so free socket data */
+		kfree_skb(skb);
+		return s;
+	}
+
 	dlci = __get_dlci(hdr->addr);
 	type = __get_type(hdr->ctrl);
 
@@ -1667,7 +1668,7 @@ static int rfcomm_recv_frame(struct rfcomm_session *s, struct sk_buff *skb)
 	if (__check_fcs(skb->data, type, fcs)) {
 		BT_ERR("bad checksum in packet");
 		kfree_skb(skb);
-		return -EILSEQ;
+		return s;
 	}
 
 	if (__test_ea(hdr->len))
@@ -1683,22 +1684,23 @@ static int rfcomm_recv_frame(struct rfcomm_session *s, struct sk_buff *skb)
 
 	case RFCOMM_DISC:
 		if (__test_pf(hdr->ctrl))
-			rfcomm_recv_disc(s, dlci);
+			s = rfcomm_recv_disc(s, dlci);
 		break;
 
 	case RFCOMM_UA:
 		if (__test_pf(hdr->ctrl))
-			rfcomm_recv_ua(s, dlci);
+			s = rfcomm_recv_ua(s, dlci);
 		break;
 
 	case RFCOMM_DM:
-		rfcomm_recv_dm(s, dlci);
+		s = rfcomm_recv_dm(s, dlci);
 		break;
 
 	case RFCOMM_UIH:
-		if (dlci)
-			return rfcomm_recv_data(s, dlci, __test_pf(hdr->ctrl), skb);
-
+		if (dlci) {
+			rfcomm_recv_data(s, dlci, __test_pf(hdr->ctrl), skb);
+			return s;
+		}
 		rfcomm_recv_mcc(s, skb);
 		break;
 
@@ -1707,7 +1709,7 @@ static int rfcomm_recv_frame(struct rfcomm_session *s, struct sk_buff *skb)
 		break;
 	}
 	kfree_skb(skb);
-	return 0;
+	return s;
 }
 
 /* ---- Connection and data processing ---- */
@@ -1844,7 +1846,7 @@ static void rfcomm_process_dlcs(struct rfcomm_session *s)
 	}
 }
 
-static void rfcomm_process_rx(struct rfcomm_session *s)
+static struct rfcomm_session *rfcomm_process_rx(struct rfcomm_session *s)
 {
 	struct socket *sock = s->sock;
 	struct sock *sk = sock->sk;
@@ -1856,17 +1858,15 @@ static void rfcomm_process_rx(struct rfcomm_session *s)
 	while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
 		skb_orphan(skb);
 		if (!skb_linearize(skb))
-			rfcomm_recv_frame(s, skb);
+			s = rfcomm_recv_frame(s, skb);
 		else
 			kfree_skb(skb);
 	}
 
-	if (sk->sk_state == BT_CLOSED) {
-		if (!s->initiator)
-			rfcomm_session_put(s);
+	if (s && (sk->sk_state == BT_CLOSED))
+		s = rfcomm_session_close(s, sk->sk_err);
 
-		rfcomm_session_close(s, sk->sk_err);
-	}
+	return s;
 }
 
 static void rfcomm_accept_connection(struct rfcomm_session *s)
@@ -1891,8 +1891,6 @@ static void rfcomm_accept_connection(struct rfcomm_session *s)
 
 	s = rfcomm_session_add(nsock, BT_OPEN);
 	if (s) {
-		rfcomm_session_hold(s);
-
 		/* We should adjust MTU on incoming sessions.
 		 * L2CAP MTU minus UIH header and FCS. */
 		s->mtu = min(l2cap_pi(nsock->sk)->chan->omtu,
@@ -1903,7 +1901,7 @@ static void rfcomm_accept_connection(struct rfcomm_session *s)
 		sock_release(nsock);
 }
 
-static void rfcomm_check_connection(struct rfcomm_session *s)
+static struct rfcomm_session *rfcomm_check_connection(struct rfcomm_session *s)
 {
 	struct sock *sk = s->sock->sk;
 
@@ -1921,10 +1919,10 @@ static void rfcomm_check_connection(struct rfcomm_session *s)
 		break;
 
 	case BT_CLOSED:
-		s->state = BT_CLOSED;
-		rfcomm_session_close(s, sk->sk_err);
+		s = rfcomm_session_close(s, sk->sk_err);
 		break;
 	}
+	return s;
 }
 
 static void rfcomm_process_sessions(void)
@@ -1940,7 +1938,6 @@ static void rfcomm_process_sessions(void)
 		if (test_and_clear_bit(RFCOMM_TIMED_OUT, &s->flags)) {
 			s->state = BT_DISCONN;
 			rfcomm_send_disc(s, 0);
-			rfcomm_session_put(s);
 			continue;
 		}
 
@@ -1949,21 +1946,18 @@ static void rfcomm_process_sessions(void)
 			continue;
 		}
 
-		rfcomm_session_hold(s);
-
 		switch (s->state) {
 		case BT_BOUND:
-			rfcomm_check_connection(s);
+			s = rfcomm_check_connection(s);
 			break;
 
 		default:
-			rfcomm_process_rx(s);
+			s = rfcomm_process_rx(s);
 			break;
 		}
 
-		rfcomm_process_dlcs(s);
-
-		rfcomm_session_put(s);
+		if (s)
+			rfcomm_process_dlcs(s);
 	}
 
 	rfcomm_unlock();
@@ -2010,10 +2004,11 @@ static int rfcomm_add_listener(bdaddr_t *ba)
 
 	/* Add listening session */
 	s = rfcomm_session_add(sock, BT_LISTEN);
-	if (!s)
+	if (!s) {
+		err = -ENOMEM;
 		goto failed;
+	}
 
-	rfcomm_session_hold(s);
 	return 0;
 failed:
 	sock_release(sock);
@@ -2071,8 +2066,6 @@ static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
 	if (!s)
 		return;
 
-	rfcomm_session_hold(s);
-
 	list_for_each_safe(p, n, &s->dlcs) {
 		d = list_entry(p, struct rfcomm_dlc, list);
 
@@ -2104,8 +2097,6 @@ static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
 			set_bit(RFCOMM_AUTH_REJECT, &d->flags);
 	}
 
-	rfcomm_session_put(s);
-
 	rfcomm_schedule();
 }