From patchwork Mon Jul 12 06:10:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 474511 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=-19.4 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, USER_AGENT_GIT 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 5A7A1C07E9C for ; Mon, 12 Jul 2021 06:24:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 42BB3611AC for ; Mon, 12 Jul 2021 06:24:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234752AbhGLG0v (ORCPT ); Mon, 12 Jul 2021 02:26:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:47700 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234801AbhGLGZ6 (ORCPT ); Mon, 12 Jul 2021 02:25:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9063361175; Mon, 12 Jul 2021 06:22:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626070976; bh=+jnQwEwgY+JBGAUVJ2F9CXKCTXjX1MPPK7IxvWL91BY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KOTwvbyzfrQw+vrwUDRBLfNWeH6OOxLGxGdLqr/gSbq7jy3XonoIyYp3Y0htNnwfW XsZEEZbW3By78IgVZgN0OKl7bfblskESH5u/A2eV82Uj49GBAsTz33i4+JpySh+5yJ x1JI0nne3wmGw78aQ9Dy+BdV9gSbRChkMfJXc7u0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vadim Fedorenko , Seth Forshee , Jakub Kicinski , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 222/348] tls: prevent oversized sendfile() hangs by ignoring MSG_MORE Date: Mon, 12 Jul 2021 08:10:06 +0200 Message-Id: <20210712060731.131670855@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060659.886176320@linuxfoundation.org> References: <20210712060659.886176320@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jakub Kicinski [ Upstream commit d452d48b9f8b1a7f8152d33ef52cfd7fe1735b0a ] We got multiple reports that multi_chunk_sendfile test case from tls selftest fails. This was sort of expected, as the original fix was never applied (see it in the first Link:). The test in question uses sendfile() with count larger than the size of the underlying file. This will make splice set MSG_MORE on all sendpage calls, meaning TLS will never close and flush the last partial record. Eric seem to have addressed a similar problem in commit 35f9c09fe9c7 ("tcp: tcp_sendpages() should call tcp_push() once") by introducing MSG_SENDPAGE_NOTLAST. Unlike MSG_MORE MSG_SENDPAGE_NOTLAST is not set on the last call of a "pipefull" of data (PIPE_DEF_BUFFERS == 16, so every 16 pages or whenever we run out of data). Having a break every 16 pages should be fine, TLS can pack exactly 4 pages into a record, so for aligned reads there should be no difference, unaligned may see one extra record per sendpage(). Sticking to TCP semantics seems preferable to modifying splice, but we can revisit it if real life scenarios show a regression. Reported-by: Vadim Fedorenko Reported-by: Seth Forshee Link: https://lore.kernel.org/netdev/1591392508-14592-1-git-send-email-pooja.trivedi@stackpath.com/ Fixes: 3c4d7559159b ("tls: kernel TLS support") Signed-off-by: Jakub Kicinski Tested-by: Seth Forshee Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/tls/tls_sw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index cdb65aa54be7..7fb5c067f429 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1150,7 +1150,7 @@ static int tls_sw_do_sendpage(struct sock *sk, struct page *page, int ret = 0; bool eor; - eor = !(flags & (MSG_MORE | MSG_SENDPAGE_NOTLAST)); + eor = !(flags & MSG_SENDPAGE_NOTLAST); sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); /* Call the sk_stream functions to manage the sndbuf mem. */