From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF6ED2C0263; Wed, 25 Feb 2026 06:56:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772002562; cv=none; b=WsZ3kSedglKnDl98N9CJiwa8zJvgRej6+FRj/bj/aOmVZyjgXJK97v+YW2i4F/xY0K/M4TdfJSDwXL5pyNopHeg8hh2x1tJzo8xSXA1CavZTIv1Oq8Kqv1wPplbmau1lihrTuryWnEYElLDr/RZ3gOM95uyePXwXlEvbUObcR34= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772002562; c=relaxed/simple; bh=WhWC/rHETpuJW08mJvAKrse5Fovu0cC/ahcZMwpibzQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fYFrR62XjjKRTsX+OLHDzYKlrDeT8b9HZ6gzM7zWJZ5eWloh1+1dJk3IISoc/HFSHo1czJaCx2BsrpRBfdA6j4tKTQGGqk1iaM7y/h80mW8/MyUZQ+eUEJQde8SCrJz1tmCTQV9VA4GYW1ZlVEcj3wTJwD6fMp/2KMwJyiGlNns= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sYa70M6A; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="sYa70M6A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F733C116D0; Wed, 25 Feb 2026 06:56:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1772002562; bh=WhWC/rHETpuJW08mJvAKrse5Fovu0cC/ahcZMwpibzQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sYa70M6AITcQ0T6x+zJR390hbPo/mLGwaiiozAwSyR/BoelBvoPeIcZ1ksMm2MCSD HtARalmYgz8OoRmPd7AA3piae/rY0YV+D7JK5r/ZYodzuqPuXPGlYkULTLW1GNAror lnwdkz+p5NZ0uJaiaFoze3esCgNdx7AKdDHQ0Xzg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Abeni , Mat Martineau , "Matthieu Baerts (NGI0)" , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 298/641] mptcp: do not account for OoO in mptcp_rcvbuf_grow() Date: Tue, 24 Feb 2026 17:20:24 -0800 Message-ID: <20260225012355.966103772@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260225012348.915798704@linuxfoundation.org> References: <20260225012348.915798704@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni [ Upstream commit 6b329393502e5857662b851a13f947209c588587 ] MPTCP-level OoOs are physiological when multiple subflows are active concurrently and will not cause retransmissions nor are caused by drops. Accounting for them in mptcp_rcvbuf_grow() causes the rcvbuf slowly drifting towards tcp_rmem[2]. Remove such accounting. Note that subflows will still account for TCP-level OoO when the MPTCP-level rcvbuf is propagated. This also closes a subtle and very unlikely race condition with rcvspace init; active sockets with user-space holding the msk-level socket lock, could complete such initialization in the receive callback, after that the first OoO data reaches the rcvbuf and potentially triggering a divide by zero Oops. Fixes: e118cdc34dd1 ("mptcp: rcvbuf auto-tuning improvement") Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260203-net-next-mptcp-misc-feat-6-20-v1-1-31ec8bfc56d1@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/mptcp/protocol.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e4bb7e2d7b19a..15a70af7b776d 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -224,9 +224,6 @@ static bool mptcp_rcvbuf_grow(struct sock *sk, u32 newval) do_div(grow, oldval); rcvwin += grow << 1; - if (!RB_EMPTY_ROOT(&msk->out_of_order_queue)) - rcvwin += MPTCP_SKB_CB(msk->ooo_last_skb)->end_seq - msk->ack_seq; - cap = READ_ONCE(net->ipv4.sysctl_tcp_rmem[2]); rcvbuf = min_t(u32, mptcp_space_from_win(sk, rcvwin), cap); @@ -350,9 +347,6 @@ static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb) end: skb_condense(skb); skb_set_owner_r(skb, sk); - /* do not grow rcvbuf for not-yet-accepted or orphaned sockets. */ - if (sk->sk_socket) - mptcp_rcvbuf_grow(sk, msk->rcvq_space.space); } static void mptcp_init_skb(struct sock *ssk, struct sk_buff *skb, int offset, -- 2.51.0