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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 DF797C10F14 for ; Tue, 16 Apr 2019 09:07:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A6E192073F for ; Tue, 16 Apr 2019 09:07:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="b+1X1kYf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728823AbfDPJHc (ORCPT ); Tue, 16 Apr 2019 05:07:32 -0400 Received: from mail.skyhub.de ([5.9.137.197]:41058 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726160AbfDPJHc (ORCPT ); Tue, 16 Apr 2019 05:07:32 -0400 Received: from zn.tnic (p200300EC2F0D6900D0FA583685BBD9D6.dip0.t-ipconnect.de [IPv6:2003:ec:2f0d:6900:d0fa:5836:85bb:d9d6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id AD7011EC030F; Tue, 16 Apr 2019 11:07:30 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1555405650; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=DXBEXhnRgnfLAJC+Rs/fi4ddHcBibz8ncG5RBTuICDY=; b=b+1X1kYfELMS31JAK8Duj5Rca9ARrZnLqIF72LJvKmLM6FlKjSugP8mLw+f5iULjH5LxeO 0v9nQXWopYW2Zcll6E2ipZo5k6IS3jYLngNHVEgOYIZHqxVy/U5fd6a0a7ZgmCET3+4jHC OC99k2mKhCXIULEyJlL/8A4yE1cYnkA= Date: Tue, 16 Apr 2019 11:07:26 +0200 From: Borislav Petkov To: Cong Wang Cc: linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org, Tony Luck , Thomas Gleixner Subject: Re: [PATCH 1/2] ras: fix an off-by-one error in __find_elem() Message-ID: <20190416090726.GD27892@zn.tnic> References: <20190416012001.5338-1-xiyou.wangcong@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190416012001.5338-1-xiyou.wangcong@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 15, 2019 at 06:20:00PM -0700, Cong Wang wrote: > ce_arr.array[] is always within the range [0, ce_arr.n-1]. > However, the binary search code in __find_elem() uses ce_arr.n > as the maximum index, which could lead to an off-by-one > out-of-bound access when the element after the last is exactly > the one just got deleted, that is, 'min' returned to caller as > 'ce_arr.n'. Sorry, I don't follow. There's a debugfs interface in /sys/kernel/debug/ras/cec/ with which you can input random PFNs and test the thing. Show me pls how this can happen with an example. Thx. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.