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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED autolearn=unavailable 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 C5D44C28CC0 for ; Wed, 29 May 2019 20:12:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A066C24134 for ; Wed, 29 May 2019 20:12:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="mD+XA/C1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726689AbfE2UMN (ORCPT ); Wed, 29 May 2019 16:12:13 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:41239 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726515AbfE2UMN (ORCPT ); Wed, 29 May 2019 16:12:13 -0400 Received: by mail-pg1-f194.google.com with SMTP id z3so525837pgp.8 for ; Wed, 29 May 2019 13:12:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=PGcw43rEtHfebZ1ykAg+O3oB9Ib7l867UUY+4n/dk/Q=; b=mD+XA/C1RPTuYpF3bAQXZIvQOGFykfuFTGv2T4SJe7rylVcI8w0NDLRy0IsBLJ66C4 yVcYvfhvVtwxJaG6tBzpFRpEcG+JM4ZK+8yr+Vmhnc0lkQZ9h7mnNWkXgsjQ03iN9T3Y xn9BTzPrq4mJgfWOD9cwdHXpGjo9qYZ06UsdU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=PGcw43rEtHfebZ1ykAg+O3oB9Ib7l867UUY+4n/dk/Q=; b=PWx84ZInnUyLkjRw5iSkbxfFoc849iM4xAi3IP5uv7FRJEg+bu2a7YtyIzySqptK2P 3QmNccbxxJCNZeLnLzQ3dYHaGoAxpTXVUdhPxJdKkM1ddr5Q8yjip8qk9X5HGsfTMdUE T8fTd6B9kBXKaPl1W0l3CjyDS+hAHVj2ECCB38K2wVzBPeKW1dOKm7NFD+4v39A8qPlx aKfQIqn2D8EHT70jEEV1Zal96N2DZW5bcqd8uWm6hX0Jo/0zG6L05m+GaB6nKSACBR/u sZzFigK/YW66N94/Jdd2dLx+jWzMWmxWmHUI8W/DK35Otv3Uh0LFGnCQqcUBoNWNbWs7 3bQQ== X-Gm-Message-State: APjAAAWwdLgiHEfZDWUrM2bQG/eaIwW9bZnTNvhghXjk+ePYEju2Rhzj 6Rk5douo33kkm51VMeo8VboJ3w== X-Google-Smtp-Source: APXvYqwDEJpc5XVklT3bHvSVgN9OxPIFPApr20V/GjXll3oEfIoQdqDbKTvTIc6ODp034anrn4Q3IQ== X-Received: by 2002:a63:f551:: with SMTP id e17mr11828943pgk.329.1559160732491; Wed, 29 May 2019 13:12:12 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id j2sm494584pfb.157.2019.05.29.13.12.11 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 29 May 2019 13:12:11 -0700 (PDT) Date: Wed, 29 May 2019 13:12:10 -0700 From: Kees Cook To: Alexandre Ghiti Cc: Andrew Morton , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Luis Chamberlain , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v4 11/14] mips: Adjust brk randomization offset to fit generic version Message-ID: <201905291311.7E88A71@keescook> References: <20190526134746.9315-1-alex@ghiti.fr> <20190526134746.9315-12-alex@ghiti.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190526134746.9315-12-alex@ghiti.fr> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, May 26, 2019 at 09:47:43AM -0400, Alexandre Ghiti wrote: > This commit simply bumps up to 32MB and 1GB the random offset > of brk, compared to 8MB and 256MB, for 32bit and 64bit respectively. > > Suggested-by: Kees Cook > Signed-off-by: Alexandre Ghiti Reviewed-by: Kees Cook -Kees > --- > arch/mips/mm/mmap.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c > index ffbe69f3a7d9..c052565b76fb 100644 > --- a/arch/mips/mm/mmap.c > +++ b/arch/mips/mm/mmap.c > @@ -16,6 +16,7 @@ > #include > #include > #include > +#include > > unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ > EXPORT_SYMBOL(shm_align_mask); > @@ -189,11 +190,11 @@ static inline unsigned long brk_rnd(void) > unsigned long rnd = get_random_long(); > > rnd = rnd << PAGE_SHIFT; > - /* 8MB for 32bit, 256MB for 64bit */ > + /* 32MB for 32bit, 1GB for 64bit */ > if (TASK_IS_32BIT_ADDR) > - rnd = rnd & 0x7ffffful; > + rnd = rnd & SZ_32M; > else > - rnd = rnd & 0xffffffful; > + rnd = rnd & SZ_1G; > > return rnd; > } > -- > 2.20.1 > -- Kees Cook