From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-83.mta0.migadu.com [91.218.175.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C988F35E1AA for ; Wed, 19 Aug 2026 11:21:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.83 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787138482; cv=none; b=pG5rDekYclsgrqHfx72a6bDkRKKlBinb8oQZr4Ehu1BjiqQ+ZZL0RnD8dNSdmtH1qk24SCb5uGa7H2gxthcp3xuk6WtMLCD6HZ86m5p39xsxiBdPy54MFb6NQxAX8DirNff9Ljl5OZcRRXoQxHrDmjSGKcR9nHvLFhrfohfWifs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787138482; c=relaxed/simple; bh=kB83V3yUg+2bzKdwztGH6E3ejAm0BGhWJR0s0PhxUm0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pl4uUKXtiQq8ZNEX9Eau0KiI+U4AFPGb/jwGD8FMz45wthJdySO30MqeXLLivCFl9/GgzcCh1MCYm9SiJKQJly6jwmzLAaqJEgSdoh/2Mc2j8K+YMroay4qR5xBc+d5imjQoaa//dAHTnCS/MvpOLHsLn/mNx62w6lNXUc7iY48= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Yjc2/0oM; arc=none smtp.client-ip=91.218.175.83 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Yjc2/0oM" X-Envelope-To: mptcp@lists.linux.dev DKIM-Signature: a=rsa-sha256; bh=kB83V3yUg+2bzKdwztGH6E3ejAm0BGhWJR0s0PhxUm0=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1787138478; v=1; x=1787743278; b=Yjc2/0oMSKReS/cj+rkKuiEkZnrKUNwLkDSO4SC1WwY/pD5+MK/nImeQsld7wGgHQ/aIhKkd MkcxBocOWcULGV7gEd7nv+WK986IPGd9YoFc4fiR4xry9D1r1hwQWxa8TFROdNZkVdTiYJcXOgQ fyBQZss0lLD/Gz1ryHWm/x0w= X-Envelope-To: mptcp@lists.linux.dev Received: from localhost.localdomain (223.70.159.239) by smtp.migadu.com with ESMTPS id 6e86423111f4f84c; Wed, 19 Aug 2026 11:21:18 +0000 X-Migadu-Flow: FLOW_OUT From: Chenguang Zhao To: mptcp@lists.linux.dev Cc: chenguang.zhao@linux.dev, Chenguang Zhao Subject: [PATCH mptcp-next RFC v5 3/3] mptcp: reject new subflows after fallback Date: Wed, 19 Aug 2026 19:21:12 +0800 Message-Id: <20260819112112.1985121-4-chenguang.zhao@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260819112112.1985121-1-chenguang.zhao@linux.dev> References: <20260819112112.1985121-1-chenguang.zhao@linux.dev> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Chenguang Zhao Check FALLBACK_DONE in mptcp_can_accept_new_subflow() so that MP_JOIN is rejected after the connection has fallen back to TCP. Signed-off-by: Chenguang Zhao --- net/mptcp/subflow.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index af81ad5e699d..c35f3bfda535 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -61,6 +61,7 @@ static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2, static bool mptcp_can_accept_new_subflow(const struct mptcp_sock *msk) { return mptcp_is_fully_established((void *)msk) && + !__mptcp_check_fallback(msk) && ((mptcp_pm_is_userspace(msk) && mptcp_userspace_pm_active(msk)) || READ_ONCE(msk->pm.accept_subflow)); -- 2.25.1