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,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 35001C33CAF for ; Thu, 16 Jan 2020 18:42:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F8CE214AF for ; Thu, 16 Jan 2020 18:42:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579200140; bh=g+lO25LH3EZ+o7YLSHIS8WaJmhR/qz9jeAD7A8xgcGo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=slByANXI/h3wCz4SGFz+UBnLZt9xKDOUMIJykArXSOR24BYHiW2dHsSIY7UkPNjXM 6IHZIuwDK72uy3SXw1MpIyVH2RQwCUknIyI4AP/asGp5UpK/tePv2+XfnpKxXFogVL mywFxcIztVOhKOwRE2FoT33d/FK2QohVy+O6AAOI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390281AbgAPRLf (ORCPT ); Thu, 16 Jan 2020 12:11:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:52078 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390235AbgAPRL1 (ORCPT ); Thu, 16 Jan 2020 12:11:27 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 DECB724681; Thu, 16 Jan 2020 17:11:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194686; bh=g+lO25LH3EZ+o7YLSHIS8WaJmhR/qz9jeAD7A8xgcGo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eyKmAGWVjC9MjaaEZoMfuKhjsS2cGot/gfiISl7jkhJLHHINIF2GSa2dBbz6jg9P0 od/t9+i+W/lcbemrHBScXrxwq3ZihdCE5s2o2Uyu5m4pe82x5p81GY4KwDTxjtkZHq m46s+PRTQBnTGBx7YUSXMaTCVXZMkVneWPHWPI+Y= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Jonathan Lemon , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 530/671] xsk: avoid store-tearing when assigning umem Date: Thu, 16 Jan 2020 12:02:48 -0500 Message-Id: <20200116170509.12787-267-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116170509.12787-1-sashal@kernel.org> References: <20200116170509.12787-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Björn Töpel [ Upstream commit 9764f4b301c3e7eb3b75eec85b73cad449cdbb0d ] The umem member of struct xdp_sock is read outside of the control mutex, in the mmap implementation, and needs a WRITE_ONCE to avoid potential store-tearing. Acked-by: Jonathan Lemon Fixes: 423f38329d26 ("xsk: add umem fill queue support and mmap") Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- net/xdp/xsk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index b580078f04d1..72caa4fb13f4 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -454,7 +454,7 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) } xdp_get_umem(umem_xs->umem); - xs->umem = umem_xs->umem; + WRITE_ONCE(xs->umem, umem_xs->umem); sockfd_put(sock); } else if (!xs->umem || !xdp_umem_validate_queues(xs->umem)) { err = -EINVAL; @@ -534,7 +534,7 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname, /* Make sure umem is ready before it can be seen by others */ smp_wmb(); - xs->umem = umem; + WRITE_ONCE(xs->umem, umem); mutex_unlock(&xs->mutex); return 0; } -- 2.20.1