Bluetooth: Make better use of l2cap_chan reference counting
L2CAP sockets contain a pointer to l2cap_chan that needs to be
reference counted in order to prevent a possible dangling pointer when
the channel is freed.
There were a few other cases where an l2cap_chan pointer on the stack
was dereferenced after a call to l2cap_chan_del. Those pointers are
also now reference counted.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Gustavo Padovan <gustavo@padovan.org>
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 1192c94..b854d28 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1256,6 +1256,7 @@
/* Kill channels */
list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
+ l2cap_chan_hold(chan);
l2cap_chan_lock(chan);
l2cap_chan_del(chan, err);
@@ -1263,6 +1264,7 @@
l2cap_chan_unlock(chan);
chan->ops->close(chan->data);
+ l2cap_chan_put(chan);
}
mutex_unlock(&conn->chan_lock);
@@ -3375,11 +3377,13 @@
sk->sk_shutdown = SHUTDOWN_MASK;
release_sock(sk);
+ l2cap_chan_hold(chan);
l2cap_chan_del(chan, ECONNRESET);
l2cap_chan_unlock(chan);
chan->ops->close(chan->data);
+ l2cap_chan_put(chan);
mutex_unlock(&conn->chan_lock);
@@ -3407,11 +3411,13 @@
l2cap_chan_lock(chan);
+ l2cap_chan_hold(chan);
l2cap_chan_del(chan, 0);
l2cap_chan_unlock(chan);
chan->ops->close(chan->data);
+ l2cap_chan_put(chan);
mutex_unlock(&conn->chan_lock);