Merging upstream version 4.19.260.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 112 insertions, 78 deletions

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index c0d64b414..65d20bdff 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -113,7 +113,8 @@ static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn,
 }
 
 /* Find channel with given SCID.
- * Returns locked channel. */
+ * Returns a reference locked channel.
+ */
 static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn,
 						 u16 cid)
 {
@@ -121,15 +122,19 @@ static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn,
 
 	mutex_lock(&conn->chan_lock);
 	c = __l2cap_get_chan_by_scid(conn, cid);
-	if (c)
-		l2cap_chan_lock(c);
+	if (c) {
+		/* Only lock if chan reference is not 0 */
+		c = l2cap_chan_hold_unless_zero(c);
+		if (c)
+			l2cap_chan_lock(c);
+	}
 	mutex_unlock(&conn->chan_lock);
 
 	return c;
 }
 
 /* Find channel with given DCID.
- * Returns locked channel.
+ * Returns a reference locked channel.
  */
 static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
 						 u16 cid)
@@ -138,8 +143,12 @@ static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
 
 	mutex_lock(&conn->chan_lock);
 	c = __l2cap_get_chan_by_dcid(conn, cid);
-	if (c)
-		l2cap_chan_lock(c);
+	if (c) {
+		/* Only lock if chan reference is not 0 */
+		c = l2cap_chan_hold_unless_zero(c);
+		if (c)
+			l2cap_chan_lock(c);
+	}
 	mutex_unlock(&conn->chan_lock);
 
 	return c;
@@ -164,8 +173,12 @@ static struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn,
 
 	mutex_lock(&conn->chan_lock);
 	c = __l2cap_get_chan_by_ident(conn, ident);
-	if (c)
-		l2cap_chan_lock(c);
+	if (c) {
+		/* Only lock if chan reference is not 0 */
+		c = l2cap_chan_hold_unless_zero(c);
+		if (c)
+			l2cap_chan_lock(c);
+	}
 	mutex_unlock(&conn->chan_lock);
 
 	return c;
@@ -491,6 +504,16 @@ void l2cap_chan_hold(struct l2cap_chan *c)
 	kref_get(&c->kref);
 }
 
+struct l2cap_chan *l2cap_chan_hold_unless_zero(struct l2cap_chan *c)
+{
+	BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
+
+	if (!kref_get_unless_zero(&c->kref))
+		return NULL;
+
+	return c;
+}
+
 void l2cap_chan_put(struct l2cap_chan *c)
 {
 	BT_DBG("chan %p orig refcnt %d", c, kref_read(&c->kref));
@@ -1781,11 +1804,11 @@ static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
 						   bdaddr_t *dst,
 						   u8 link_type)
 {
-	struct l2cap_chan *c, *c1 = NULL;
+	struct l2cap_chan *c, *tmp, *c1 = NULL;
 
 	read_lock(&chan_list_lock);
 
-	list_for_each_entry(c, &chan_list, global_l) {
+	list_for_each_entry_safe(c, tmp, &chan_list, global_l) {
 		if (state && c->state != state)
 			continue;
 
@@ -1803,7 +1826,9 @@ static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
 			src_match = !bacmp(&c->src, src);
 			dst_match = !bacmp(&c->dst, dst);
 			if (src_match && dst_match) {
-				l2cap_chan_hold(c);
+				if (!l2cap_chan_hold_unless_zero(c))
+					continue;
+
 				read_unlock(&chan_list_lock);
 				return c;
 			}
@@ -1818,7 +1843,7 @@ static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
 	}
 
 	if (c1)
-		l2cap_chan_hold(c1);
+		c1 = l2cap_chan_hold_unless_zero(c1);
 
 	read_unlock(&chan_list_lock);
 
@@ -4204,6 +4229,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn,
 
 unlock:
 	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
 	return err;
 }
 
@@ -4316,6 +4342,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn,
 
 done:
 	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
 	return err;
 }
 
@@ -5044,6 +5071,7 @@ send_move_response:
 	l2cap_send_move_chan_rsp(chan, result);
 
 	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
 
 	return 0;
 }
@@ -5136,6 +5164,7 @@ static void l2cap_move_continue(struct l2cap_conn *conn, u16 icid, u16 result)
 	}
 
 	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
 }
 
 static void l2cap_move_fail(struct l2cap_conn *conn, u8 ident, u16 icid,
@@ -5165,6 +5194,7 @@ static void l2cap_move_fail(struct l2cap_conn *conn, u8 ident, u16 icid,
 	l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
 
 	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
 }
 
 static int l2cap_move_channel_rsp(struct l2cap_conn *conn,
@@ -5228,6 +5258,7 @@ static int l2cap_move_channel_confirm(struct l2cap_conn *conn,
 	l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
 
 	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
 
 	return 0;
 }
@@ -5263,6 +5294,7 @@ static inline int l2cap_move_channel_confirm_rsp(struct l2cap_conn *conn,
 	}
 
 	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
 
 	return 0;
 }
@@ -5635,12 +5667,11 @@ static inline int l2cap_le_credits(struct l2cap_conn *conn,
 	if (credits > max_credits) {
 		BT_ERR("LE credits overflow");
 		l2cap_send_disconn_req(chan, ECONNRESET);
-		l2cap_chan_unlock(chan);
 
 		/* Return 0 so that we don't trigger an unnecessary
 		 * command reject packet.
 		 */
-		return 0;
+		goto unlock;
 	}
 
 	chan->tx_credits += credits;
@@ -5651,7 +5682,9 @@ static inline int l2cap_le_credits(struct l2cap_conn *conn,
 	if (chan->tx_credits)
 		chan->ops->resume(chan);
 
+unlock:
 	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
 
 	return 0;
 }
@@ -6949,6 +6982,7 @@ drop:
 
 done:
 	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
 }
 
 static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm,
@@ -7353,7 +7387,7 @@ static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c,
 		if (src_type != c->src_type)
 			continue;
 
-		l2cap_chan_hold(c);
+		c = l2cap_chan_hold_unless_zero(c);
 		read_unlock(&chan_list_lock);
 		return c;
 	}
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index b98225d65..e4eaf5d2a 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -552,22 +552,58 @@ struct rfcomm_dlc *rfcomm_dlc_exists(bdaddr_t *src, bdaddr_t *dst, u8 channel)
 	return dlc;
 }
 
+static int rfcomm_dlc_send_frag(struct rfcomm_dlc *d, struct sk_buff *frag)
+{
+	int len = frag->len;
+
+	BT_DBG("dlc %p mtu %d len %d", d, d->mtu, len);
+
+	if (len > d->mtu)
+		return -EINVAL;
+
+	rfcomm_make_uih(frag, d->addr);
+	__skb_queue_tail(&d->tx_queue, frag);
+
+	return len;
+}
+
 int rfcomm_dlc_send(struct rfcomm_dlc *d, struct sk_buff *skb)
 {
-	int len = skb->len;
+	unsigned long flags;
+	struct sk_buff *frag, *next;
+	int len;
 
 	if (d->state != BT_CONNECTED)
 		return -ENOTCONN;
 
-	BT_DBG("dlc %p mtu %d len %d", d, d->mtu, len);
+	frag = skb_shinfo(skb)->frag_list;
+	skb_shinfo(skb)->frag_list = NULL;
 
-	if (len > d->mtu)
-		return -EINVAL;
+	/* Queue all fragments atomically. */
+	spin_lock_irqsave(&d->tx_queue.lock, flags);
 
-	rfcomm_make_uih(skb, d->addr);
-	skb_queue_tail(&d->tx_queue, skb);
+	len = rfcomm_dlc_send_frag(d, skb);
+	if (len < 0 || !frag)
+		goto unlock;
+
+	for (; frag; frag = next) {
+		int ret;
+
+		next = frag->next;
+
+		ret = rfcomm_dlc_send_frag(d, frag);
+		if (ret < 0) {
+			kfree_skb(frag);
+			goto unlock;
+		}
+
+		len += ret;
+	}
+
+unlock:
+	spin_unlock_irqrestore(&d->tx_queue.lock, flags);
 
-	if (!test_bit(RFCOMM_TX_THROTTLED, &d->flags))
+	if (len > 0 && !test_bit(RFCOMM_TX_THROTTLED, &d->flags))
 		rfcomm_schedule();
 	return len;
 }
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index c044ff2f7..78830efe8 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -578,46 +578,20 @@ static int rfcomm_sock_sendmsg(struct socket *sock, struct msghdr *msg,
 	lock_sock(sk);
 
 	sent = bt_sock_wait_ready(sk, msg->msg_flags);
-	if (sent)
-		goto done;
-
-	while (len) {
-		size_t size = min_t(size_t, len, d->mtu);
-		int err;
-
-		skb = sock_alloc_send_skb(sk, size + RFCOMM_SKB_RESERVE,
-				msg->msg_flags & MSG_DONTWAIT, &err);
-		if (!skb) {
-			if (sent == 0)
-				sent = err;
-			break;
-		}
-		skb_reserve(skb, RFCOMM_SKB_HEAD_RESERVE);
-
-		err = memcpy_from_msg(skb_put(skb, size), msg, size);
-		if (err) {
-			kfree_skb(skb);
-			if (sent == 0)
-				sent = err;
-			break;
-		}
 
-		skb->priority = sk->sk_priority;
+	release_sock(sk);
 
-		err = rfcomm_dlc_send(d, skb);
-		if (err < 0) {
-			kfree_skb(skb);
-			if (sent == 0)
-				sent = err;
-			break;
-		}
+	if (sent)
+		return sent;
 
-		sent += size;
-		len  -= size;
-	}
+	skb = bt_skb_sendmmsg(sk, msg, len, d->mtu, RFCOMM_SKB_HEAD_RESERVE,
+			      RFCOMM_SKB_TAIL_RESERVE);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
 
-done:
-	release_sock(sk);
+	sent = rfcomm_dlc_send(d, skb);
+	if (sent < 0)
+		kfree_skb(skb);
 
 	return sent;
 }
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 14b5288d1..ee321d62b 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -279,12 +279,10 @@ static int sco_connect(struct hci_dev *hdev, struct sock *sk)
 	return err;
 }
 
-static int sco_send_frame(struct sock *sk, void *buf, int len,
-			  unsigned int msg_flags)
+static int sco_send_frame(struct sock *sk, struct sk_buff *skb)
 {
 	struct sco_conn *conn = sco_pi(sk)->conn;
-	struct sk_buff *skb;
-	int err;
+	int len = skb->len;
 
 	/* Check outgoing MTU */
 	if (len > conn->mtu)
@@ -292,11 +290,6 @@ static int sco_send_frame(struct sock *sk, void *buf, int len,
 
 	BT_DBG("sk %p len %d", sk, len);
 
-	skb = bt_skb_send_alloc(sk, len, msg_flags & MSG_DONTWAIT, &err);
-	if (!skb)
-		return err;
-
-	memcpy(skb_put(skb, len), buf, len);
 	hci_send_sco(conn->hcon, skb);
 
 	return len;
@@ -715,7 +708,7 @@ static int sco_sock_sendmsg(struct socket *sock, struct msghdr *msg,
 			    size_t len)
 {
 	struct sock *sk = sock->sk;
-	void *buf;
+	struct sk_buff *skb;
 	int err;
 
 	BT_DBG("sock %p, sk %p", sock, sk);
@@ -727,24 +720,21 @@ static int sco_sock_sendmsg(struct socket *sock, struct msghdr *msg,
 	if (msg->msg_flags & MSG_OOB)
 		return -EOPNOTSUPP;
 
-	buf = kmalloc(len, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	if (memcpy_from_msg(buf, msg, len)) {
-		kfree(buf);
-		return -EFAULT;
-	}
+	skb = bt_skb_sendmsg(sk, msg, len, len, 0, 0);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
 
 	lock_sock(sk);
 
 	if (sk->sk_state == BT_CONNECTED)
-		err = sco_send_frame(sk, buf, len, msg->msg_flags);
+		err = sco_send_frame(sk, skb);
 	else
 		err = -ENOTCONN;
 
 	release_sock(sk);
-	kfree(buf);
+
+	if (err < 0)
+		kfree_skb(skb);
 	return err;
 }