From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 33233513576; Thu, 17 Sep 2026 13:06:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789650385; cv=none; b=dw8qtIq6mQ8b5NVHJ4H1ZSOt3Hw5BXY22ucASOvKxaqhgvuNNhWvh10/zrowZJTjOKJl4z2H8/k+4bKxOX3jxsgk8rFXHPHZ0jWoeoHao1CCycw9DLmYGFWpnYg9FxlSM8Mu8zbxKtiXBVdoW4W35Wv1hm1P7ECbTyhshTi7C1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789650385; c=relaxed/simple; bh=9w+WvPJ3aYLp6/wS57Jaw4mb7DboOndjnFZXPTxC+Io=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=FnGFkUIWTfiHkCdX5JYmEdTNuNBjpEm2D+hYYMCu+58Gmph3UUx/MFjKqZNsz4r8qXHNlvcYXkDkoSM8P1kISqMfTDXI4s5zQxYawCDo9XMCBnEsIXAzN1WpAoqNcbwizTldwrTm9dS/m6CxImTqMK8Y7Frr6fuAUzQ/2QifWWw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=S0G4MVG0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="S0G4MVG0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3DE891F00898; Thu, 17 Sep 2026 13:06:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789650377; bh=ZKTqy+1rn/oN3Z6QFh4uh2VTISqwBFW4uCXZoAX0i+w=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=S0G4MVG0RK6xFMse93B3m1CE6bQOgHD4vfy2AXzWTgXDcxsjsMKPOmgF3JRZ7kka9 BSPpdXThzmIA1QFyfpvpNMitA2gts2XA5qxRk8Eo+Vde8FtOwXOa26XJvzwb4Yy7+3 ySnrzgeLHc1Qb5YeAk2kkjTYiePdKKGDBXZNhw5VlOWp9Cr3LTmwn+GnN/0XDHa3Y2 GBiDJyOnuIv1n02nTT6by8b5G/KVBM0G81/ke0Pr7L5J67d3w3Tcrkfab0uuP7sp4o n/iZRAWY7iQ18tvvhafNeksm+CrU/P17spo8n9ghDI2yuKkH1Za5H6SFXBhAwsxz3s wmR7aQFSmCkFA== From: "Matthieu Baerts (NGI0)" Date: Thu, 17 Sep 2026 15:05:58 +0200 Subject: [PATCH net v2 2/3] mptcp: close race between scheduler and state change Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260917-net-mptcp-misc-fixes-7-3-rc4-v2-2-0cf5c72667c8@kernel.org> References: <20260917-net-mptcp-misc-fixes-7-3-rc4-v2-0-0cf5c72667c8@kernel.org> In-Reply-To: <20260917-net-mptcp-misc-fixes-7-3-rc4-v2-0-0cf5c72667c8@kernel.org> To: Mat Martineau , Geliang Tang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman Cc: netdev@vger.kernel.org, mptcp@lists.linux.dev, "Matthieu Baerts (NGI0)" , stable@vger.kernel.org, Shardul Bankar , Xinyang Ge X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1369; i=matttbe@kernel.org; h=from:subject:message-id; bh=Ola5B1/PLL6OtlWpXMLg0kumciF1N+qOuxhUivE0uDw=; b=owGbwMvMwCVWo/Th0Gd3rumMp9WSGLJWPz0whecR74ugGXZzChc9XvbANaOBRyRn6/9b31a6m nw42n+qvaOUhUGMi0FWTJFFui0yf+bzKt4SLz8LmDmsTCBDGLg4BWAiu4sZfrMudCxxORqoXfgh rOQXU85aszQDrYYVk0JOqisKPwg5f43hv9MyhZ3/jhQ7bPuvIFnDs21bg9irFTylj/lXVdhIC31 nZgAA X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 From: Paolo Abeni The mptcp scheduler may race with subflow sockets state change: data transmission on the selected socket may fail and a later release could try to use mss_now reset to 0 for a divide operation. Address the issue by explicitly checking for the critical scenario. Fixes: c886d70286bf ("mptcp: do not queue data on closed subflows") Cc: stable@vger.kernel.org Reported-by: Shardul Bankar Reported-by: Xinyang Ge Closes: https://lore.kernel.org/20260525194828.1137119-1-shardul.b@mpiricsoftware.com Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) --- net/mptcp/protocol.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index d9fc3be9d2db..577d0134b9ec 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1664,7 +1664,9 @@ struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) static void mptcp_push_release(struct sock *ssk, struct mptcp_sendmsg_info *info) { - tcp_push(ssk, 0, info->mss_now, tcp_sk(ssk)->nonagle, info->size_goal); + if (info->mss_now) + tcp_push(ssk, 0, info->mss_now, tcp_sk(ssk)->nonagle, + info->size_goal); release_sock(ssk); } -- 2.55.0