This is a note to let you know that I've just added the patch titled
[PATCH stable 5.9 07/24] mptcp: subflows garbage collection
to the 5.9-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-subflows-garbage-collection.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Sat Oct 17 08:52:03 AM CEST 2020
From: Paolo Abeni <pabeni@xxxxxxxxxx>
Date: Fri, 9 Oct 2020 19:00:01 +0200
Subject: [PATCH stable 5.9 07/24] mptcp: subflows garbage collection
From: Paolo Abeni <pabeni@xxxxxxxxxx>
[ Upstream commit 0e4f35d7880157ceccf0a58377d778b02762af82 ]
The msk can close MP_JOIN subflows if the initial handshake
fails. Currently such subflows are kept alive in the
conn_list until the msk itself is closed.
Beyond the wasted memory, we could end-up sending the
DATA_FIN and the DATA_FIN ack on such socket, even after a
reset.
Fixes: 43b54c6ee382 ("mptcp: Use full MPTCP-level disconnect state machine")
Reviewed-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mptcp/protocol.c | 17 +++++++++++++++++
net/mptcp/protocol.h | 1 +
net/mptcp/subflow.c | 6 ++++++
3 files changed, 24 insertions(+)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1383,6 +1383,20 @@ static void pm_work(struct mptcp_sock *m
spin_unlock_bh(&msk->pm.lock);
}
+static void __mptcp_close_subflow(struct mptcp_sock *msk)
+{
+ struct mptcp_subflow_context *subflow, *tmp;
+
+ list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
+ struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+
+ if (inet_sk_state_load(ssk) != TCP_CLOSE)
+ continue;
+
+ __mptcp_close_ssk((struct sock *)msk, ssk, subflow, 0);
+ }
+}
+
static void mptcp_worker(struct work_struct *work)
{
struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work);
@@ -1400,6 +1414,9 @@ static void mptcp_worker(struct work_str
mptcp_clean_una(sk);
mptcp_check_data_fin_ack(sk);
__mptcp_flush_join_list(msk);
+ if (test_and_clear_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags))
+ __mptcp_close_subflow(msk);
+
__mptcp_move_skbs(msk);
if (msk->pm.status)
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -90,6 +90,7 @@
#define MPTCP_WORK_RTX 2
#define MPTCP_WORK_EOF 3
#define MPTCP_FALLBACK_DONE 4
+#define MPTCP_WORK_CLOSE_SUBFLOW 5
struct mptcp_options_received {
u64 sndr_key;
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -272,9 +272,15 @@ static bool subflow_thmac_valid(struct m
void mptcp_subflow_reset(struct sock *ssk)
{
+ struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
+ struct sock *sk = subflow->conn;
+
tcp_set_state(ssk, TCP_CLOSE);
tcp_send_active_reset(ssk, GFP_ATOMIC);
tcp_done(ssk);
+ if (!test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &mptcp_sk(sk)->flags) &&
+ schedule_work(&mptcp_sk(sk)->work))
+ sock_hold(sk);
}
static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
Patches currently in stable-queue which might be from pabeni@xxxxxxxxxx are
queue-5.9/mptcp-fix-fallback-for-mp_join-subflows.patch
queue-5.9/net-mptcp-make-dack4-dack8-usage-consistent-among-all-subflows.patch
queue-5.9/mptcp-subflows-garbage-collection.patch
