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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 461EAC3A59D for ; Thu, 22 Aug 2019 09:13:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 18ACB233A2 for ; Thu, 22 Aug 2019 09:13:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="oD4EOZEx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733050AbfHVJN6 (ORCPT ); Thu, 22 Aug 2019 05:13:58 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:47101 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733031AbfHVJN6 (ORCPT ); Thu, 22 Aug 2019 05:13:58 -0400 Received: by mail-pl1-f194.google.com with SMTP id c2so3083382plz.13; Thu, 22 Aug 2019 02:13:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=hGbD6Vh1mloKQbpoh3OOnJ9gcUMT0+HhT1PxglNKnQ4=; b=oD4EOZExG+ViTUs34Nz4fr9HAR3KqkVaabDSDUJ+MjRtyaTNIqhlKPXiZqV32kJ98J VJ+37FYjgo8yx/7Jsy18DMOmrObmLe9+VxOJvL6o0bd1c78mPcFdU1QGRSxpAbqROkzy rY5D5A0kjyEzljg+sSS+3l2jZa/W5YzwxDymfimyuK3ZP7aiS3bKNGDRb/0KK6DcM4eT bUQit+sstfJPFT0wWo3lVxLsn0YFTmRxnBlaO7Ckv9MaKpYT6tRRfw9Xvzzp1D3ee/xj HJvjtPnCc4YFURtyazf23ZTP0GDEABjw7gzwb7Zw8E/YZ9mveaTT3A2v6WM89rcxjTpT 9L/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=hGbD6Vh1mloKQbpoh3OOnJ9gcUMT0+HhT1PxglNKnQ4=; b=gUfjR65e+wxtSs99AvYfjXq93e8tQ3QbM25hAHRmj4dZ3Lj67MFcW4bmGrBDdeQ7i9 ELlK0x5Nuo52D0IUkNCZ1of9IFaLfuQedrylvcLRH4ABr37GYG6NgejNI+Nm+wc/c35d bG3Rj7tBS2WE4DskjJNXIPzj25EyoXkVVlkpNgVP33Ia3hJ8qwR2jrZO4qfwOLQ4fsGG l3rZ5z/CNKZc7vWDOmHl+Ce0YcMEqMPSlZH8lcQok27bV8adiU0RYSnXNsh68g87YSAN pqZmn4JFQr1ynOl9tX+P64MYHI6iWzpCVrI3fm9+rqq8qP551tjZfzqBgPqfR5DIwaEC I6aw== X-Gm-Message-State: APjAAAXgMdXbqRtGXvLb9kDtnxgvu1E5bOwU0+tjq98akGX8yAJA1dzf 06ebBZqgvZO6mQm7UdNT5GoSPtbkPkMWlg== X-Google-Smtp-Source: APXvYqxiz0DJV27uKMnA2sX0w4wTc/ukPA0yKjGYFfOFDrd+Y0G2ViWlcaqxS9Fi7Y9f5bk419YRXQ== X-Received: by 2002:a17:902:f01:: with SMTP id 1mr37197450ply.337.1566465237693; Thu, 22 Aug 2019 02:13:57 -0700 (PDT) Received: from btopel-mobl.ger.intel.com ([192.55.54.43]) by smtp.gmail.com with ESMTPSA id w207sm28414754pff.93.2019.08.22.02.13.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Aug 2019 02:13:57 -0700 (PDT) From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= To: ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org Cc: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , magnus.karlsson@intel.com, magnus.karlsson@gmail.com, bpf@vger.kernel.org, jonathan.lemon@gmail.com, syzbot+c82697e3043781e08802@syzkaller.appspotmail.com, hdanton@sina.com, i.maximets@samsung.com Subject: [PATCH bpf-next 3/4] xsk: avoid store-tearing when assigning umem Date: Thu, 22 Aug 2019 11:13:05 +0200 Message-Id: <20190822091306.20581-4-bjorn.topel@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190822091306.20581-1-bjorn.topel@gmail.com> References: <20190822091306.20581-1-bjorn.topel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Björn Töpel 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 potentional store-tearing. Fixes: 423f38329d26 ("xsk: add umem fill queue support and mmap") Signed-off-by: Björn Töpel --- net/xdp/xsk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 31236e61069b..6dde1857ed52 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -718,7 +718,7 @@ 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