This is a note to let you know that I've just added the patch titled
mptcp: fix active subflow finalization
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mptcp-fix-active-subflow-finalization.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 55b47ca7d80814ceb63d64e032e96cd6777811e5 Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@xxxxxxxxxx>
Date: Wed, 31 May 2023 12:37:08 -0700
Subject: mptcp: fix active subflow finalization
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
@@ -821,6 +821,13 @@ 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;
@@ -835,6 +842,7 @@ 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;
}
@@ -3485,14 +3493,16 @@ 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);
@@ -3515,11 +3525,6 @@ 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;
}
Patches currently in stable-queue which might be from pabeni@xxxxxxxxxx are
queue-6.1/net-dsa-mv88e6xxx-increase-wait-after-reset-deactiva.patch
queue-6.1/net-smc-don-t-use-rmbs-not-mapped-to-new-link-in-smc.patch
queue-6.1/net-smc-scan-from-current-rmb-list-when-no-position-.patch
queue-6.1/udp6-fix-race-condition-in-udp6_sendmsg-connect.patch
queue-6.1/selftests-mptcp-connect-skip-if-mptcp-is-not-supported.patch
queue-6.1/mptcp-add-annotations-around-msk-subflow-accesses.patch
queue-6.1/selftests-mptcp-sockopt-skip-if-mptcp-is-not-supported.patch
queue-6.1/mptcp-fix-data-race-around-msk-first-access.patch
queue-6.1/mptcp-avoid-unneeded-__mptcp_nmpc_socket-usage.patch
queue-6.1/selftests-mptcp-join-skip-if-mptcp-is-not-supported.patch
queue-6.1/selftests-mptcp-pm-nl-skip-if-mptcp-is-not-supported.patch
queue-6.1/tcp-deny-tcp_disconnect-when-threads-are-waiting.patch
queue-6.1/selftests-mptcp-userspace-pm-skip-if-mptcp-is-not-supported.patch
queue-6.1/net-sched-flower-fix-possible-oob-write-in-fl_set_ge.patch
queue-6.1/mptcp-consolidate-passive-msk-socket-initialization.patch
queue-6.1/mptcp-fix-active-subflow-finalization.patch
queue-6.1/mptcp-avoid-unneeded-address-copy.patch
queue-6.1/mptcp-simplify-subflow_syn_recv_sock.patch
queue-6.1/mptcp-add-annotations-around-sk-sk_shutdown-accesses.patch
queue-6.1/mptcp-fix-connect-timeout-handling.patch
queue-6.1/tcp-fix-mishandling-when-the-sack-compression-is-def.patch
