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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 A544BC6786E for ; Fri, 26 Oct 2018 15:49:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5984B20665 for ; Fri, 26 Oct 2018 15:49:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Bkt3CilG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5984B20665 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727573AbeJ0A04 (ORCPT ); Fri, 26 Oct 2018 20:26:56 -0400 Received: from mail-it1-f196.google.com ([209.85.166.196]:54567 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726113AbeJ0A04 (ORCPT ); Fri, 26 Oct 2018 20:26:56 -0400 Received: by mail-it1-f196.google.com with SMTP id l191-v6so2055259ita.4; Fri, 26 Oct 2018 08:49:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=12bmE5QnwITRe19O+4Lh8FzmnBXQCECHHswUc0rYW9I=; b=Bkt3CilGSZANlYi1+AqA15/MuOk6WAtGe5lzuk0LSwRpJuIAqvcCf5gDDfqdPgLU41 c/o1cOTsssDyHPMA3FuQJKxbgtczj7yNMftO+91ajSfk3AqllaS0ycUDkeQMl6PUntor UTG5os7PuXcFcdGtwxm//IhiUm1ZyCoqxg1HNyFZwVTLK1NriANRrFce175rCnPnHV9x x6u9Ekoxw0jN6iG12tJwqV5o5Bs2WsCHgDArykaS23UoV25RkjVQeBiCkEYqxYWyc/VG b9MLyaIcxPdaoq3zVvuYuKAbUF/pT6UJJfYZ1k3Oe71s8aH4nV2K9sO8w8ryYSCyPGpp fa+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=12bmE5QnwITRe19O+4Lh8FzmnBXQCECHHswUc0rYW9I=; b=VMI0sjjBXtXjoxYhgCFsSAa9enp/yBD3oflLa9cb+S39nsg9SyLp8nJLGQGF1n/JEi MHxlcJWenUlf8IfhrJkNJG52L7cw+pDz3Nb0STI1GPy7tWaCOx8Y5pLFuXNN6bYDPCi2 SP4OoOT/6fTi7cLEDizNSTGW+ti1l+rGOGneL+KRHupZrP3ylUSXBYKrfyxj4RGLtSYV wZiSI4+PWpzORbbHhaYYvXeKBYsFzqj9E5mKIrx9HVkllBNklZSNl7GB2yZyMSFiQwz2 F5IrYtngPOL600kgt+ephPg71tomVziceemX/hHoqCHXPKk6dLzJ++qsGmeBlVBcrfoj 3mrw== X-Gm-Message-State: AGRZ1gLLD4+eV8iiWs2mik2ysaIV5xC2G5yWy44FdMMH9Ah9rszJXS86 okR2xrF8IXZcAesQvBCO53PtBAB9NU3GtCXtkSc= X-Google-Smtp-Source: AJdET5crwffZ5m8dA9R2lOop4dS0zZPzb1FytjJnUq8mhyD1BlUj1WRXqcF8C/zj9C+D3j6MKPWgBxIqEdZRlWB1fks= X-Received: by 2002:a02:8a74:: with SMTP id e49-v6mr2978673jal.81.1540568962339; Fri, 26 Oct 2018 08:49:22 -0700 (PDT) MIME-Version: 1.0 References: <1540567279.66186.99.camel@acm.org> In-Reply-To: <1540567279.66186.99.camel@acm.org> From: Kyungtae Kim Date: Fri, 26 Oct 2018 11:49:10 -0400 Message-ID: Subject: Re: [PATCH] floppy: Avoid memory access beyond the array bounds in setup_rw_floppy() To: bvanassche@acm.org Cc: Jens Axboe , jikos@kernel.org, Byoungyoung Lee , DaeRyong Jeong , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thank you for your reply. > Against which kernel tree did you prepare this patch? Just above the code > you want to insert I found the following: > > if (ptr->cmd_count > 33) ... Yes, I saw that code as well. But I find out there is no more additional code relevant to it. So I guess, that is for like reserved ones for the future work (e.g., RESTORE). And such code cannot solve this crash issue because the crash happens even when cmd_count is less than 33. > or not? Anyway, I don't think it makes sense first to compare cmd_count against > 33 and next to compare it against 16 ... I agree. So far, seems that removing if (ptr->cmd_count > 33) looks better. Please let me know if you have better ideas. > This comparison looks suspicious to me. Almost every comparison of the type > "... > ARRAY_SIZE()" I have seen so far was wrong and should be changed into > "... >= ARRAY_SIZE()" instead. Well, let me check this part again. Thanks, Kyungtae Kim