From: Paolo Abeni <pabeni@xxxxxxxxxx>
commit 55b47ca7d80814ceb63d64e032e96cd6777811e5 upstream.
Active subflow are inserted into the connection list at creation time.
When the MPJ handshake completes successfully, a new subflow creation
netlink event is generated correctly, but the current code wrongly
avoid initializing a couple of subflow data.
The above will cause misbehavior on a few exceptional events: unneeded
mptcp-level retransmission on msk-level sequence wrap-around and infinite
mapping fallback even when a MPJ socket is present.
Address the issue factoring out the needed initialization in a new helper
and invoking the latter from __mptcp_finish_join() time for passive
subflow and from mptcp_finish_join() for active ones.
Fixes: 0530020a7c8f ("mptcp: track and update contiguous data status")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Mat Martineau <martineau@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mptcp/protocol.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -812,6 +812,13 @@ void mptcp_data_ready(struct sock *sk, s
mptcp_data_unlock(sk);
}
+static void mptcp_subflow_joined(struct mptcp_sock *msk, struct sock *ssk)
+{
+ mptcp_subflow_ctx(ssk)->map_seq = READ_ONCE(msk->ack_seq);
+ WRITE_ONCE(msk->allow_infinite_fallback, false);
+ mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
+}
+
static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk)
{
struct sock *sk = (struct sock *)msk;
@@ -826,6 +833,7 @@ static bool __mptcp_finish_join(struct m
mptcp_sock_graft(ssk, sk->sk_socket);
mptcp_sockopt_sync_locked(msk, ssk);
+ mptcp_subflow_joined(msk, ssk);
return true;
}
@@ -3457,14 +3465,16 @@ bool mptcp_finish_join(struct sock *ssk)
return false;
}
- if (!list_empty(&subflow->node))
- goto out;
+ /* active subflow, already present inside the conn_list */
+ if (!list_empty(&subflow->node)) {
+ mptcp_subflow_joined(msk, ssk);
+ return true;
+ }
if (!mptcp_pm_allow_new_subflow(msk))
goto err_prohibited;
- /* active connections are already on conn_list.
- * If we can't acquire msk socket lock here, let the release callback
+ /* If we can't acquire msk socket lock here, let the release callback
* handle it
*/
mptcp_data_lock(parent);
@@ -3487,11 +3497,6 @@ err_prohibited:
return false;
}
- subflow->map_seq = READ_ONCE(msk->ack_seq);
- WRITE_ONCE(msk->allow_infinite_fallback, false);
-
-out:
- mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
return true;
}
