This is a note to let you know that I've just added the patch titled
mptcp: fix potential wake-up event loss
to the 6.6-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-potential-wake-up-event-loss.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b111d8fbd2cbc63e05f3adfbbe0d4df655dfcc5b Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@xxxxxxxxxx>
Date: Fri, 23 Feb 2024 17:14:16 +0100
Subject: mptcp: fix potential wake-up event loss
From: Paolo Abeni <pabeni@xxxxxxxxxx>
commit b111d8fbd2cbc63e05f3adfbbe0d4df655dfcc5b upstream.
After the blamed commit below, the send buffer auto-tuning can
happen after that the mptcp_propagate_sndbuf() completes - via
the delegated action infrastructure.
We must check for write space even after such change or we risk
missing the wake-up event.
Fixes: 8005184fd1ca ("mptcp: refactor sndbuf auto-tuning")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240223-upstream-net-20240223-misc-fixes-v1-6-162e87e48497@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mptcp/protocol.h | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -772,6 +772,16 @@ static inline bool mptcp_data_fin_enable
READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
}
+static inline void mptcp_write_space(struct sock *sk)
+{
+ if (sk_stream_is_writeable(sk)) {
+ /* pairs with memory barrier in mptcp_poll */
+ smp_mb();
+ if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
+ sk_stream_write_space(sk);
+ }
+}
+
static inline void __mptcp_sync_sndbuf(struct sock *sk)
{
struct mptcp_subflow_context *subflow;
@@ -790,6 +800,7 @@ static inline void __mptcp_sync_sndbuf(s
/* the msk max wmem limit is <nr_subflows> * tcp wmem[2] */
WRITE_ONCE(sk->sk_sndbuf, new_sndbuf);
+ mptcp_write_space(sk);
}
/* The called held both the msk socket and the subflow socket locks,
@@ -820,16 +831,6 @@ static inline void mptcp_propagate_sndbu
local_bh_enable();
}
-static inline void mptcp_write_space(struct sock *sk)
-{
- if (sk_stream_is_writeable(sk)) {
- /* pairs with memory barrier in mptcp_poll */
- smp_mb();
- if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
- sk_stream_write_space(sk);
- }
-}
-
void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags);
#define MPTCP_TOKEN_MAX_RETRIES 4
Patches currently in stable-queue which might be from pabeni@xxxxxxxxxx are
queue-6.6/mptcp-push-at-dss-boundaries.patch
queue-6.6/mptcp-fix-snd_wnd-initialization-for-passive-socket.patch
queue-6.6/mptcp-fix-potential-wake-up-event-loss.patch
queue-6.6/mptcp-fix-possible-deadlock-in-subflow-diag.patch
queue-6.6/veth-try-harder-when-allocating-queue-memory.patch
queue-6.6/mptcp-avoid-printing-warning-once-on-client-side.patch
queue-6.6/gtp-fix-use-after-free-and-null-ptr-deref-in-gtp_newlink.patch
queue-6.6/net-hsr-use-correct-offset-for-hsr-tlv-values-in-sup.patch
