From patchwork Wed Nov 18 22:05:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Abeni X-Patchwork-Id: 327818 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28993C5519F for ; Wed, 18 Nov 2020 22:06:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD776246DC for ; Wed, 18 Nov 2020 22:06:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Kj+rspu1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727167AbgKRWGR (ORCPT ); Wed, 18 Nov 2020 17:06:17 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:43549 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725822AbgKRWGR (ORCPT ); Wed, 18 Nov 2020 17:06:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605737176; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=NdjeARxGuLTeRkhnnivxFdfoRVbvyIFUDejtLn+aBXk=; b=Kj+rspu1cbJC6uj2LEePAyRdp7FoJ0WvLfduRNh7u7KH7jR7glVwf9I6glz0TVraE6E9IK RCUsDhcXWDrvF8vp8+X7u6EYARVbBfRi8S/p3T3sGJxOMwe0Ev9Co4FJQelZ4p3h85Kqz7 ePUkW/jREPjbCg3pr73MGrMyzUjDLEI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-98-6P_4UpxaP4SfaOehq43F4w-1; Wed, 18 Nov 2020 17:06:14 -0500 X-MC-Unique: 6P_4UpxaP4SfaOehq43F4w-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2F20C89CCC0; Wed, 18 Nov 2020 22:06:13 +0000 (UTC) Received: from gerbillo.redhat.com (ovpn-112-97.ams2.redhat.com [10.36.112.97]) by smtp.corp.redhat.com (Postfix) with ESMTP id AACA160C05; Wed, 18 Nov 2020 22:06:11 +0000 (UTC) From: Paolo Abeni To: netdev@vger.kernel.org Cc: Jakub Kicinski , mptcp@lists.01.org Subject: [PATCH net-next] mptcp: update rtx timeout only if required. Date: Wed, 18 Nov 2020 23:05:34 +0100 Message-Id: <1a72039f112cae048c44d398ffa14e0a1432db3d.1605737083.git.pabeni@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We must start the retransmission timer only there are pending data in the rtx queue. Otherwise we can hit a WARN_ON in mptcp_reset_timer(), as syzbot demonstrated. Reported-and-tested-by: syzbot+42aa53dafb66a07e5a24@syzkaller.appspotmail.com Fixes: d9ca1de8c0cd ("mptcp: move page frag allocation in mptcp_sendmsg()") Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Reported-by: Naresh Kamboju Tested-by: Naresh Kamboju --- net/mptcp/protocol.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 8df013daea88..aeda4357de9a 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1261,11 +1261,12 @@ static void mptcp_push_pending(struct sock *sk, unsigned int flags) mptcp_push_release(sk, ssk, &info); out: - /* start the timer, if it's not pending */ - if (!mptcp_timer_pending(sk)) - mptcp_reset_timer(sk); - if (copied) + if (copied) { + /* start the timer, if it's not pending */ + if (!mptcp_timer_pending(sk)) + mptcp_reset_timer(sk); __mptcp_check_send_data_fin(sk); + } } static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)