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,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 797EEC3A59E for ; Mon, 26 Aug 2019 06:11:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C7BC217F4 for ; Mon, 26 Aug 2019 06:11:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Em844pTp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729385AbfHZGLb (ORCPT ); Mon, 26 Aug 2019 02:11:31 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:42660 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729348AbfHZGLa (ORCPT ); Mon, 26 Aug 2019 02:11:30 -0400 Received: by mail-pf1-f193.google.com with SMTP id i30so11081354pfk.9; Sun, 25 Aug 2019 23:11:30 -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=MXb24woiG3vysdnh2s/h7S9B75FkjdRNzF9eK8dEZkQ=; b=Em844pTpiX2dTIuGbxD5rHts6qiIuBWjFNpE63v90SbvL/nmEuOjCNW4RSSuO+7tHc 54aNcRRDilJtY3naKW5iXRlMoOuUzJ8O3xWVNSJvgdwfFACf/A6ADSpc/G3ouhNFZP6+ B6FeWFHMNsyk9x3MGvzop+vIRCec0TU3WJ19G7vzRdPXjNq97xQtNUj9seokb6d2ZgTX VAohEHVkZvz/OLwegWGwNRuGMHOzGzh13pLGZmgMFCZ1gJYdMAy9VdeJRlXPDC33gFxr Q/96FODxity/7nf8qtC4Pkng4m93fsg2DD/bFm3m3Cu0/+12yPeeGEN/pwDYCFQDY+gr 2x9Q== 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=MXb24woiG3vysdnh2s/h7S9B75FkjdRNzF9eK8dEZkQ=; b=V5wN8kKSl1oyLFgJ5Q/JLjaF+//+De8plgqkVIVIO6Qt3ovSBWQdOMXWINbAoRf9zS 5NGlDRQ6gvyAt3iOXqCWrgDQxwFyOAhyIyNFvFGI7JcRwt46R7dWSMJIFN6+ouXjFLfg ljo5WrCbSkXKf6cu/xv0s45RP3064y75n1znCpgDbp62UfjRBi8o69Fpmpwk15aMPmJf 8XhKOcTEJGVuZZuqDeGpDbjuz+0mAAJMVdKWqDekxwHXJcrsR8p94Lloqqa+YCwCkxfE vwAtrIvAV7NKZ80tb53h8yUovNROha0xjnDfcLMvj80dkoVcop4YKqgeL0Wu0PlQ7xZb 1V8Q== X-Gm-Message-State: APjAAAUhIymgj8l6sqy4n8Akl8EqiSUVwEwuPLMzCKvNrO2k5q5I/r0k q6WGlSDFCwWxqN6gxY5UZVY= X-Google-Smtp-Source: APXvYqwWSpmSNI8hJ5viwyWNEVsstNYclKqJDblCk4pRLmfn1+UYo4DMOprkxnHkxFRjPS/UxAlTNA== X-Received: by 2002:a17:90a:a78b:: with SMTP id f11mr16676229pjq.16.1566799890173; Sun, 25 Aug 2019 23:11:30 -0700 (PDT) Received: from btopel-mobl.ger.intel.com ([192.55.54.42]) by smtp.gmail.com with ESMTPSA id d2sm9567452pjs.21.2019.08.25.23.11.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 25 Aug 2019 23:11:29 -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 v2 3/4] xsk: avoid store-tearing when assigning umem Date: Mon, 26 Aug 2019 08:10:52 +0200 Message-Id: <20190826061053.15996-4-bjorn.topel@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190826061053.15996-1-bjorn.topel@gmail.com> References: <20190826061053.15996-1-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. Acked-by: Jonathan Lemon 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 8fafa3ce3ae6..e3e99ee5631b 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -716,7 +716,7 @@ 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