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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 43EEEC76195 for ; Mon, 15 Jul 2019 14:03:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D675212F5 for ; Mon, 15 Jul 2019 14:03:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563199390; bh=saYp66UYcTDDQpWG5VhqspncKjwKOnk1Hdx4A4GhGMU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dwoV6FkF6UqrUQp6IS6giW+3gWt+J8z3qM0AIYhWabpPT+oB/5HbuQoKkU40xgiDX /SB5v18hwWryLmk03nlcUmaLfTcAlbcKSBhFke8ACajlW0tkxLU2iaytQnSf/BJptt o7maw2YtzN+r/wQ35oYFq2OOmWoh+E6P2zBA1ro0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387742AbfGOODE (ORCPT ); Mon, 15 Jul 2019 10:03:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:47186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387455AbfGOODD (ORCPT ); Mon, 15 Jul 2019 10:03:03 -0400 Received: from sasha-vm.mshome.net (unknown [73.61.17.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DBE47217D9; Mon, 15 Jul 2019 14:02:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563199382; bh=saYp66UYcTDDQpWG5VhqspncKjwKOnk1Hdx4A4GhGMU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qmk9mkRJ6XAZ0jyCNl6dIyPDJPLSxnYLklgb+RKl5jD0B9J/xaJO/xv4huUr8/Ujv atjpS1v8pBwOCKwA/2FXnlKe+Zuto4i6zCN4q0ZdMFPRxe9f0AhE7Kl8hGKFHX8EQ1 ozSsw5Yog6LDvqyUBk57L42uLa+PMknD+3EXukCw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ilya Maximets , Magnus Karlsson , William Tu , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org, xdp-newbies@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 248/249] xdp: fix race on generic receive path Date: Mon, 15 Jul 2019 09:46:53 -0400 Message-Id: <20190715134655.4076-248-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190715134655.4076-1-sashal@kernel.org> References: <20190715134655.4076-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ilya Maximets [ Upstream commit bf0bdd1343efbbf65b4d53aef1fce14acbd79d50 ] Unlike driver mode, generic xdp receive could be triggered by different threads on different CPU cores at the same time leading to the fill and rx queue breakage. For example, this could happen while sending packets from two processes to the first interface of veth pair while the second part of it is open with AF_XDP socket. Need to take a lock for each generic receive to avoid race. Fixes: c497176cb2e4 ("xsk: add Rx receive functions and poll support") Signed-off-by: Ilya Maximets Acked-by: Magnus Karlsson Tested-by: William Tu Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- include/net/xdp_sock.h | 2 ++ net/xdp/xsk.c | 31 ++++++++++++++++++++++--------- 2 files changed, 24 insertions(+), 9 deletions(-) diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index d074b6d60f8a..ac3c047d058c 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -67,6 +67,8 @@ struct xdp_sock { * in the SKB destructor callback. */ spinlock_t tx_completion_lock; + /* Protects generic receive. */ + spinlock_t rx_lock; u64 rx_dropped; }; diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index a14e8864e4fa..5e0637db92ea 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -123,13 +123,17 @@ int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) u64 addr; int err; - if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) - return -EINVAL; + spin_lock_bh(&xs->rx_lock); + + if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) { + err = -EINVAL; + goto out_unlock; + } if (!xskq_peek_addr(xs->umem->fq, &addr) || len > xs->umem->chunk_size_nohr - XDP_PACKET_HEADROOM) { - xs->rx_dropped++; - return -ENOSPC; + err = -ENOSPC; + goto out_drop; } addr += xs->umem->headroom; @@ -138,13 +142,21 @@ int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) memcpy(buffer, xdp->data_meta, len + metalen); addr += metalen; err = xskq_produce_batch_desc(xs->rx, addr, len); - if (!err) { - xskq_discard_addr(xs->umem->fq); - xsk_flush(xs); - return 0; - } + if (err) + goto out_drop; + + xskq_discard_addr(xs->umem->fq); + xskq_produce_flush_desc(xs->rx); + spin_unlock_bh(&xs->rx_lock); + + xs->sk.sk_data_ready(&xs->sk); + return 0; + +out_drop: xs->rx_dropped++; +out_unlock: + spin_unlock_bh(&xs->rx_lock); return err; } @@ -765,6 +777,7 @@ static int xsk_create(struct net *net, struct socket *sock, int protocol, xs = xdp_sk(sk); mutex_init(&xs->mutex); + spin_lock_init(&xs->rx_lock); spin_lock_init(&xs->tx_completion_lock); mutex_lock(&net->xdp.lock); -- 2.20.1