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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 2A898C2D0DB for ; Fri, 24 Jan 2020 11:31:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F141320704 for ; Fri, 24 Jan 2020 11:31:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579865505; bh=ZrNIB5c/Dpraf2+dyHOY3QdZBesP0tyTXZwse2eGJIM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DLkU6S8g3n/47hDUr7q2Nrdlv2srBCtCDnVDwBJt7zDOyOnHdpVzPZS1amVqr8pFK Mp2Yny1zP5SFNpoIt8FL0Ztk8vuy5qDQxmA9Z7/1fk9KPuEfOQqnwdWSKMUydh9T7W w1h7REOnq7Li9BZ8Qxb37YtH5FRjhvjwHmlV3Xqc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404137AbgAXLbl (ORCPT ); Fri, 24 Jan 2020 06:31:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:50064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391894AbgAXLbg (ORCPT ); Fri, 24 Jan 2020 06:31:36 -0500 Received: from localhost (ip-213-127-102-57.ip.prioritytelecom.net [213.127.102.57]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AF0B5206D4; Fri, 24 Jan 2020 11:31:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579865495; bh=ZrNIB5c/Dpraf2+dyHOY3QdZBesP0tyTXZwse2eGJIM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rOyu3pIw4ar+aN5l9FS5/WgAmzWW9xzoJ8qok17XBqOlda+mA7fu8yFO/8Jffg6uu kE0lSD2jaaNsa9HDxRjaUapvggaoZl9wiWcr4OvHsGzUsN+ZPOhu0Vj8TstpwYp0uu UkE3TbPvpKvpTTtHfcMLzlKFjFolU0KREBZibOGc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jonathan Lemon , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Daniel Borkmann , Sasha Levin Subject: [PATCH 4.19 544/639] xsk: avoid store-tearing when assigning umem Date: Fri, 24 Jan 2020 10:31:54 +0100 Message-Id: <20200124093157.222069051@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124093047.008739095@linuxfoundation.org> References: <20200124093047.008739095@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 b580078f04d15..72caa4fb13f47 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