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=-3.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 C64D2C3A59F for ; Mon, 26 Aug 2019 17:54:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C19620850 for ; Mon, 26 Aug 2019 17:54:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="iedmC87R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731134AbfHZRyh (ORCPT ); Mon, 26 Aug 2019 13:54:37 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:40453 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728280AbfHZRyh (ORCPT ); Mon, 26 Aug 2019 13:54:37 -0400 Received: by mail-pf1-f195.google.com with SMTP id w16so12267023pfn.7; Mon, 26 Aug 2019 10:54:36 -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=kM47wPSGoWQoKFogwJD1jolEo0D/cEX5m8eHxwo2vmQ=; b=iedmC87RDiN0rkKMrHaCW54/21FsAuYp/o982i8HQTHXbjjgoD24hQL17mlz2hW/Mz XR8Zk5zgWBm1C2JcQ3is3EDkonIWZX8KNrTRxsz/Zn509ULREYzqW7lA85lYSAqPuxay 8C+LTArBpQyfE3G39o6KOm1TdNbj83KdGqbLrKAQVn5+oKEeJC/u15Cb5jhR7XjffzaD t5B6RsNKKKCvQ8xRA8SDkymSqOlb2Xl8TKAutP2tWnwDfHc8pwt2QRU7vI3obhzjW/8+ 9gBRzNqc5lrez2M3EvOG53p6Dii6ge9PmWMhFXlDKb/XWwjI83NEHac/PaRH17aiEI+a Gdtw== 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=kM47wPSGoWQoKFogwJD1jolEo0D/cEX5m8eHxwo2vmQ=; b=bZGjbzuR0ved1WpexIMJey0mN/wx+ny/8E3+E5RGVg85+3zMZ9LmOj6b4tVk3SVXx5 /Rte0Gxx7xkCugmnONBqwkUb3gfV8h4iTPc9b1yu/QId08TJdR/icgVmBakxIz/uD0IU cotKkFA6yc4utNrVOj5v0+JA8oZmQDpyXCAkWIW1BF340lglC+jyPp+zI61DLGpRwdjN Rwo8z16WJ29r9Wn0r6MTxcJV0kBL16w7TSvu6Ml4l6uhpFppPpRGVdnJspcUficzkgca Yru6pNXPG+rRlI8NUMk9iJnl2Dd47aPSg2jUQUATPW5XGq7IFmRvtoSl/WQF5JaAVAuF QwfA== X-Gm-Message-State: APjAAAWtJIuPtPCFuESvoBuVDtd/FyciYLBb65/VNTFj96+Slx+Eds4g t9il04sJpDEN/W61PUA1QOg= X-Google-Smtp-Source: APXvYqwrKVgW/Wh3U3M1lg8TqtrE/XLv1cAH3bWW5OOQV84UFc1x3cXXXJuNpcRae5TcStbVh+FVGg== X-Received: by 2002:a17:90a:2667:: with SMTP id l94mr21578665pje.74.1566842076513; Mon, 26 Aug 2019 10:54:36 -0700 (PDT) Received: from [172.20.53.188] ([2620:10d:c090:200::3:2982]) by smtp.gmail.com with ESMTPSA id 10sm14047831pfv.63.2019.08.26.10.54.35 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Aug 2019 10:54:35 -0700 (PDT) From: "Jonathan Lemon" To: "=?utf-8?b?QmrDtnJuIFTDtnBlbA==?=" Cc: ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org, "=?utf-8?b?QmrDtnJuIFTDtnBlbA==?=" , magnus.karlsson@intel.com, magnus.karlsson@gmail.com, bpf@vger.kernel.org, syzbot+c82697e3043781e08802@syzkaller.appspotmail.com, hdanton@sina.com, i.maximets@samsung.com Subject: Re: [PATCH bpf-next v2 2/4] xsk: add proper barriers and {READ, WRITE}_ONCE-correctness for state Date: Mon, 26 Aug 2019 10:54:34 -0700 X-Mailer: MailMate (1.12.5r5635) Message-ID: <324C76C6-2D31-4509-A22D-4796694A4FBC@gmail.com> In-Reply-To: <20190826061053.15996-3-bjorn.topel@gmail.com> References: <20190826061053.15996-1-bjorn.topel@gmail.com> <20190826061053.15996-3-bjorn.topel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 25 Aug 2019, at 23:10, Björn Töpel wrote: > From: Björn Töpel > > The state variable was read, and written outside the control mutex > (struct xdp_sock, mutex), without proper barriers and {READ, > WRITE}_ONCE correctness. > > In this commit this issue is addressed, and the state member is now > used a point of synchronization whether the socket is setup correctly > or not. > > This also fixes a race, found by syzcaller, in xsk_poll() where umem > could be accessed when stale. > > Suggested-by: Hillf Danton > Reported-by: syzbot+c82697e3043781e08802@syzkaller.appspotmail.com > Fixes: 77cd0d7b3f25 ("xsk: add support for need_wakeup flag in AF_XDP > rings") > Signed-off-by: Björn Töpel Acked-by: Jonathan Lemon