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-rw-r--r--net/mptcp/protocol.c20
-rw-r--r--net/mptcp/protocol.h4
-rw-r--r--net/mptcp/subflow.c19
3 files changed, 35 insertions, 8 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index f6f93957275b..b7ad030dfe89 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1662,6 +1662,8 @@ static void mptcp_set_nospace(struct sock *sk)
set_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags);
}
+static int mptcp_disconnect(struct sock *sk, int flags);
+
static int mptcp_sendmsg_fastopen(struct sock *sk, struct sock *ssk, struct msghdr *msg,
size_t len, int *copied_syn)
{
@@ -1672,9 +1674,9 @@ static int mptcp_sendmsg_fastopen(struct sock *sk, struct sock *ssk, struct msgh
lock_sock(ssk);
msg->msg_flags |= MSG_DONTWAIT;
msk->connect_flags = O_NONBLOCK;
- msk->is_sendmsg = 1;
+ msk->fastopening = 1;
ret = tcp_sendmsg_fastopen(ssk, msg, copied_syn, len, NULL);
- msk->is_sendmsg = 0;
+ msk->fastopening = 0;
msg->msg_flags = saved_flags;
release_sock(ssk);
@@ -1688,6 +1690,8 @@ static int mptcp_sendmsg_fastopen(struct sock *sk, struct sock *ssk, struct msgh
*/
if (ret && ret != -EINPROGRESS && ret != -ERESTARTSYS && ret != -EINTR)
*copied_syn = 0;
+ } else if (ret && ret != -EINPROGRESS) {
+ mptcp_disconnect(sk, 0);
}
return ret;
@@ -2353,7 +2357,7 @@ static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
/* otherwise tcp will dispose of the ssk and subflow ctx */
if (ssk->sk_state == TCP_LISTEN) {
tcp_set_state(ssk, TCP_CLOSE);
- mptcp_subflow_queue_clean(ssk);
+ mptcp_subflow_queue_clean(sk, ssk);
inet_csk_listen_stop(ssk);
mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CLOSED);
}
@@ -2989,6 +2993,14 @@ static int mptcp_disconnect(struct sock *sk, int flags)
{
struct mptcp_sock *msk = mptcp_sk(sk);
+ /* We are on the fastopen error path. We can't call straight into the
+ * subflows cleanup code due to lock nesting (we are already under
+ * msk->firstsocket lock). Do nothing and leave the cleanup to the
+ * caller.
+ */
+ if (msk->fastopening)
+ return 0;
+
inet_sk_state_store(sk, TCP_CLOSE);
mptcp_stop_timer(sk);
@@ -3532,7 +3544,7 @@ static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
/* if reaching here via the fastopen/sendmsg path, the caller already
* acquired the subflow socket lock, too.
*/
- if (msk->is_sendmsg)
+ if (msk->fastopening)
err = __inet_stream_connect(ssock, uaddr, addr_len, msk->connect_flags, 1);
else
err = inet_stream_connect(ssock, uaddr, addr_len, msk->connect_flags);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 955fb3d88eb3..a0d1658ce59e 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -295,7 +295,7 @@ struct mptcp_sock {
u8 recvmsg_inq:1,
cork:1,
nodelay:1,
- is_sendmsg:1;
+ fastopening:1;
int connect_flags;
struct work_struct work;
struct sk_buff *ooo_last_skb;
@@ -628,7 +628,7 @@ void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
struct mptcp_subflow_context *subflow);
void __mptcp_subflow_send_ack(struct sock *ssk);
void mptcp_subflow_reset(struct sock *ssk);
-void mptcp_subflow_queue_clean(struct sock *ssk);
+void mptcp_subflow_queue_clean(struct sock *sk, struct sock *ssk);
void mptcp_sock_graft(struct sock *sk, struct socket *parent);
struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);
bool __mptcp_close(struct sock *sk, long timeout);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index d1d32a66ae3f..bd387d4b5a38 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1791,7 +1791,7 @@ static void subflow_state_change(struct sock *sk)
}
}
-void mptcp_subflow_queue_clean(struct sock *listener_ssk)
+void mptcp_subflow_queue_clean(struct sock *listener_sk, struct sock *listener_ssk)
{
struct request_sock_queue *queue = &inet_csk(listener_ssk)->icsk_accept_queue;
struct mptcp_sock *msk, *next, *head = NULL;
@@ -1840,8 +1840,23 @@ void mptcp_subflow_queue_clean(struct sock *listener_ssk)
do_cancel_work = __mptcp_close(sk, 0);
release_sock(sk);
- if (do_cancel_work)
+ if (do_cancel_work) {
+ /* lockdep will report a false positive ABBA deadlock
+ * between cancel_work_sync and the listener socket.
+ * The involved locks belong to different sockets WRT
+ * the existing AB chain.
+ * Using a per socket key is problematic as key
+ * deregistration requires process context and must be
+ * performed at socket disposal time, in atomic
+ * context.
+ * Just tell lockdep to consider the listener socket
+ * released here.
+ */
+ mutex_release(&listener_sk->sk_lock.dep_map, _RET_IP_);
mptcp_cancel_work(sk);
+ mutex_acquire(&listener_sk->sk_lock.dep_map,
+ SINGLE_DEPTH_NESTING, 0, _RET_IP_);
+ }
sock_put(sk);
}