Bluetooth: Hold socket in defer callback in L2CAP socket

In both places that we use the defer callback the socket lock is held for
a indirect sk access inside __l2cap_change_state() and chan->ops->defer(),
all the rest of the code between lock_sock() and release_sock() is
already protected by the channel lock and won't be affected by this
change.

We now use l2cap_change_state(), the locked version of the change state
function, and the defer callback does the locking itself now. This does
not affect other uses of the defer callback.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 4141545..049e1c8 100644 (file)
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1299,20 +1299,16 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
                        rsp.dcid = cpu_to_le16(chan->scid);
 
                        if (l2cap_chan_check_security(chan)) {
-                               struct sock *sk = chan->sk;
-
-                               lock_sock(sk);
                                if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
                                        rsp.result = __constant_cpu_to_le16(L2CAP_CR_PEND);
                                        rsp.status = __constant_cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
                                        chan->ops->defer(chan);
 
                                } else {
-                                       __l2cap_state_change(chan, BT_CONFIG);
+                                       l2cap_state_change(chan, BT_CONFIG);
                                        rsp.result = __constant_cpu_to_le16(L2CAP_CR_SUCCESS);
                                        rsp.status = __constant_cpu_to_le16(L2CAP_CS_NO_INFO);
                                }
-                               release_sock(sk);
                        } else {
                                rsp.result = __constant_cpu_to_le16(L2CAP_CR_PEND);
                                rsp.status = __constant_cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
@@ -6643,31 +6639,26 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
                                __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
                        }
                } else if (chan->state == BT_CONNECT2) {
-                       struct sock *sk = chan->sk;
                        struct l2cap_conn_rsp rsp;
                        __u16 res, stat;
 
-                       lock_sock(sk);
-
                        if (!status) {
                                if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
                                        res = L2CAP_CR_PEND;
                                        stat = L2CAP_CS_AUTHOR_PEND;
                                        chan->ops->defer(chan);
                                } else {
-                                       __l2cap_state_change(chan, BT_CONFIG);
+                                       l2cap_state_change(chan, BT_CONFIG);
                                        res = L2CAP_CR_SUCCESS;
                                        stat = L2CAP_CS_NO_INFO;
                                }
                        } else {
-                               __l2cap_state_change(chan, BT_DISCONN);
+                               l2cap_state_change(chan, BT_DISCONN);
                                __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
                                res = L2CAP_CR_SEC_BLOCK;
                                stat = L2CAP_CS_NO_INFO;
                        }
 
-                       release_sock(sk);
-
                        rsp.scid   = cpu_to_le16(chan->dcid);
                        rsp.dcid   = cpu_to_le16(chan->scid);
                        rsp.result = cpu_to_le16(res);

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index a0b31db..e559992 100644 (file)
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -1195,11 +1195,15 @@ static void l2cap_sock_ready_cb(struct l2cap_chan *chan)
 
 static void l2cap_sock_defer_cb(struct l2cap_chan *chan)
 {
-       struct sock *sk = chan->data;
-       struct sock *parent = bt_sk(sk)->parent;
+       struct sock *parent, *sk = chan->data;
+
+       lock_sock(sk);
 
+       parent = bt_sk(sk)->parent;
        if (parent)
                parent->sk_data_ready(parent, 0);
+
+       release_sock(sk);
 }
 
 static void l2cap_sock_resume_cb(struct l2cap_chan *chan)