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 4D8DB509EFA; Wed, 30 Sep 2026 16:27:10 +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=1790785636; cv=none; b=cjD+nLXJS5x4y7JaHxXYTjbZ5JrKIfoPxSH5MLLlvvQ31ZAcsfxgDDkfjFi0/+qJMkPBftQyDOcsvQLfzO/OsH9UCMd60OwrSqbiNdmS8zVmlbFUWfQ7KH5IQrsuvRY//YlCCcmYhWz7818xAg4rWEACsx53P53bmB8mML/Gz5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790785636; c=relaxed/simple; bh=08ClHAAKZLnfOv9wlhIHbplHfxqW44bQCXW80LG1je8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FqZpTSI9fHoIkc5+GSb03Owz+Bn4987QOq1HKZYzD7qXAc3X12p6/K1kMaSv5VvFjjw7mOJgwQU7N5rwnUZ+qPS2T2qFgulIlYGzMlONjVtAJXSJGuuo64y3m0tBN2IhvIQ7GKxqkoHZpmj86jYnGLV3G0B+MknM0RblP381ZzE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gqPQKebm; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gqPQKebm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4BB91F00893; Wed, 30 Sep 2026 16:27:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790785628; bh=EhyKz27YhotVHAm9WwOiiQsqPV0qPKl8Yy1fdgjuJNo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gqPQKebmG+8SeMTUPWUkAgQtUhF7CRoBtwqJDmotYf98v1ljwvFCk0xd5VKG8ZbOH X6S7LVaLiiIx0SRS2C2DCkkX2/ZJXmHYNXS/D/pYxcTbKBHybiiyB3oQbJiakSiowQ beKV7MyS1x0Y/r4yk2QhdlPJlO61n7SCamGC4Zxk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shardul Bankar , Xinyang Ge , Paolo Abeni , "Matthieu Baerts (NGI0)" , Jakub Kicinski Subject: [PATCH 6.1 575/982] mptcp: close race between scheduler and state change Date: Wed, 30 Sep 2026 17:21:51 +0200 Message-ID: <20260930152429.122392930@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152416.775402466@linuxfoundation.org> References: <20260930152416.775402466@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni commit 42064de57fb83231fcc89663a94885f228a1ee53 upstream. 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) Link: https://patch.msgid.link/20260917-net-mptcp-misc-fixes-7-3-rc4-v2-2-0cf5c72667c8@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Matthieu Baerts (NGI0) Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1636,7 +1636,9 @@ static struct sock *mptcp_subflow_get_se 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); }