FAILED: patch "[PATCH] mptcp: fix missing wakeups in edge scenarios" failed to apply to 6.18-stable tree

FAILED: patch "[PATCH] mptcp: fix missing wakeups in edge scenarios" failed to apply to 6.18-stable tree

[gregkh]

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 9d8d28738f24b75616d6ca7a27cb4aed88520343
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026061533-ninja-scrabble-539d@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9d8d28738f24b75616d6ca7a27cb4aed88520343 Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@redhat.com>
Date: Tue, 2 Jun 2026 22:14:08 +1000
Subject: [PATCH] mptcp: fix missing wakeups in edge scenarios

The mptcp_recvmsg() can fill MPTCP socket receive queue via
mptcp_move_skbs(), but currently does not try to wakeup any listener,
because the same process is going to check the receive queue soon.

When multiple threads are reading from the same fd, the above can
cause stall. Add the missing wakeup.

Fixes: 6771bfd9ee24 ("mptcp: update mptcp ack sequence from work queue")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-1-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index a72a6ad6ee8b..5a20ab2789ae 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2276,6 +2276,10 @@ static bool mptcp_move_skbs(struct sock *sk)
 		mptcp_backlog_spooled(sk, moved, &skbs);
 	}
 	mptcp_data_unlock(sk);
+
+	if (enqueued && mptcp_epollin_ready(sk))
+		sk->sk_data_ready(sk);
+
 	return enqueued;
 }
 

[PATCH 6.18.y 1/2] mptcp: fix missing wakeups in edge scenarios

[Sasha Levin]

From: Paolo Abeni <pabeni@redhat.com>

[ Upstream commit 9d8d28738f24b75616d6ca7a27cb4aed88520343 ]

The mptcp_recvmsg() can fill MPTCP socket receive queue via
mptcp_move_skbs(), but currently does not try to wakeup any listener,
because the same process is going to check the receive queue soon.

When multiple threads are reading from the same fd, the above can
cause stall. Add the missing wakeup.

Fixes: 6771bfd9ee24 ("mptcp: update mptcp ack sequence from work queue")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-1-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mptcp/protocol.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 32b2717b97ae43..f42c552ebac3b5 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2181,6 +2181,10 @@ static bool __mptcp_move_skbs(struct sock *sk)
 	__mptcp_ofo_queue(msk);
 	if (ret)
 		mptcp_check_data_fin((struct sock *)msk);
+
+	if (ret && mptcp_epollin_ready(sk))
+		sk->sk_data_ready(sk);
+
 	return ret;
 }
 
-- 
2.53.0

Re: [PATCH 6.18.y 1/2] mptcp: fix missing wakeups in edge scenarios

[Matthieu Baerts]

Hi Sasha,

On 16/06/2026 02:19, Sasha Levin wrote:
> From: Paolo Abeni <pabeni@redhat.com>
> 
> [ Upstream commit 9d8d28738f24b75616d6ca7a27cb4aed88520343 ]
> 
> The mptcp_recvmsg() can fill MPTCP socket receive queue via
> mptcp_move_skbs(), but currently does not try to wakeup any listener,
> because the same process is going to check the receive queue soon.
> 
> When multiple threads are reading from the same fd, the above can
> cause stall. Add the missing wakeup.
> 
> Fixes: 6771bfd9ee24 ("mptcp: update mptcp ack sequence from work queue")
> Cc: stable@vger.kernel.org
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
> Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-1-856831229976@kernel.org
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> Signed-off-by: Sasha Levin <sashal@kernel.org>

Thank you for this patch. The subject shows "1/2", suggesting a 2nd
patch is expected, but I don't see any, and it looks like no 2nd patch
is needed here to resolve conflicts.

So just to be sure: no patch 2/2 expected, right?

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.

Re: [PATCH 6.18.y 1/2] mptcp: fix missing wakeups in edge scenarios

[Sasha Levin]

On Tue, Jun 16, 2026 at 01:01:34PM +0200, Matthieu Baerts wrote:
>Hi Sasha,
>
>On 16/06/2026 02:19, Sasha Levin wrote:
>> From: Paolo Abeni <pabeni@redhat.com>
>>
>> [ Upstream commit 9d8d28738f24b75616d6ca7a27cb4aed88520343 ]
>>
>> The mptcp_recvmsg() can fill MPTCP socket receive queue via
>> mptcp_move_skbs(), but currently does not try to wakeup any listener,
>> because the same process is going to check the receive queue soon.
>>
>> When multiple threads are reading from the same fd, the above can
>> cause stall. Add the missing wakeup.
>>
>> Fixes: 6771bfd9ee24 ("mptcp: update mptcp ack sequence from work queue")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
>> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
>> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
>> Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-1-856831229976@kernel.org
>> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>
>Thank you for this patch. The subject shows "1/2", suggesting a 2nd
>patch is expected, but I don't see any, and it looks like no 2nd patch
>is needed here to resolve conflicts.
>
>So just to be sure: no patch 2/2 expected, right?

Yes, sorry, human error...

-- 
Thanks,
Sasha