From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C6DEC54EE9 for ; Mon, 29 Aug 2022 11:14:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230423AbiH2LOw (ORCPT ); Mon, 29 Aug 2022 07:14:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229849AbiH2LNW (ORCPT ); Mon, 29 Aug 2022 07:13:22 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80FF56A487; Mon, 29 Aug 2022 04:09:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 31326B80F9A; Mon, 29 Aug 2022 11:08:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B79CC433D6; Mon, 29 Aug 2022 11:08:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661771296; bh=AhGtrVBP7bDxvnER6WTSl2DiSMmDV+/B2DOAWezXJQc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tytShonrGEv/w78+lLrtgpxvF/GM7Gb2kZdzAGe3U1F1P0uL6eLUoQ+7J1nI5Ycdw 4caGbvws91EyD8Jh0OzdKBhSbyhmEDm9VGMfMYnmw2Nr2P7wk13YkhGJl3ofTQ6w35 /WEjp6wDJkNHdO1BCJeJZLvj0SB6s5CoNf5u/rB0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" , Sasha Levin Subject: [PATCH 5.10 48/86] net: Fix data-races around netdev_max_backlog. Date: Mon, 29 Aug 2022 12:59:14 +0200 Message-Id: <20220829105758.493453346@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220829105756.500128871@linuxfoundation.org> References: <20220829105756.500128871@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit 5dcd08cd19912892586c6082d56718333e2d19db ] While reading netdev_max_backlog, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. While at it, we remove the unnecessary spaces in the doc. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- Documentation/admin-guide/sysctl/net.rst | 2 +- net/core/dev.c | 4 ++-- net/core/gro_cells.c | 2 +- net/xfrm/espintcp.c | 2 +- net/xfrm/xfrm_input.c | 2 +- 5 files changed, 6 insertions(+), 6 deletions(-) diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index f2ab8a5b6a4b8..7f553859dba82 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -271,7 +271,7 @@ poll cycle or the number of packets processed reaches netdev_budget. netdev_max_backlog ------------------ -Maximum number of packets, queued on the INPUT side, when the interface +Maximum number of packets, queued on the INPUT side, when the interface receives packets faster than kernel can process them. netdev_rss_key diff --git a/net/core/dev.c b/net/core/dev.c index 701a1afc91ff1..215c43aecc67e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4516,7 +4516,7 @@ static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen) struct softnet_data *sd; unsigned int old_flow, new_flow; - if (qlen < (netdev_max_backlog >> 1)) + if (qlen < (READ_ONCE(netdev_max_backlog) >> 1)) return false; sd = this_cpu_ptr(&softnet_data); @@ -4564,7 +4564,7 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu, if (!netif_running(skb->dev)) goto drop; qlen = skb_queue_len(&sd->input_pkt_queue); - if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) { + if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) { if (qlen) { enqueue: __skb_queue_tail(&sd->input_pkt_queue, skb); diff --git a/net/core/gro_cells.c b/net/core/gro_cells.c index 6eb2e5ec2c506..2f66f3f295630 100644 --- a/net/core/gro_cells.c +++ b/net/core/gro_cells.c @@ -26,7 +26,7 @@ int gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb) cell = this_cpu_ptr(gcells->cells); - if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) { + if (skb_queue_len(&cell->napi_skbs) > READ_ONCE(netdev_max_backlog)) { drop: atomic_long_inc(&dev->rx_dropped); kfree_skb(skb); diff --git a/net/xfrm/espintcp.c b/net/xfrm/espintcp.c index 1f08ebf7d80c5..24ca49ecebea3 100644 --- a/net/xfrm/espintcp.c +++ b/net/xfrm/espintcp.c @@ -170,7 +170,7 @@ int espintcp_queue_out(struct sock *sk, struct sk_buff *skb) { struct espintcp_ctx *ctx = espintcp_getctx(sk); - if (skb_queue_len(&ctx->out_queue) >= netdev_max_backlog) + if (skb_queue_len(&ctx->out_queue) >= READ_ONCE(netdev_max_backlog)) return -ENOBUFS; __skb_queue_tail(&ctx->out_queue, skb); diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c index 61e6220ddd5ae..77e82033ad700 100644 --- a/net/xfrm/xfrm_input.c +++ b/net/xfrm/xfrm_input.c @@ -782,7 +782,7 @@ int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb, trans = this_cpu_ptr(&xfrm_trans_tasklet); - if (skb_queue_len(&trans->queue) >= netdev_max_backlog) + if (skb_queue_len(&trans->queue) >= READ_ONCE(netdev_max_backlog)) return -ENOBUFS; BUILD_BUG_ON(sizeof(struct xfrm_trans_cb) > sizeof(skb->cb)); -- 2.35.1