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=-7.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 03BAFC282DD for ; Thu, 18 Apr 2019 05:30:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A061B217F9 for ; Thu, 18 Apr 2019 05:30:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="edeVbOaB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A061B217F9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 55BF96B0005; Thu, 18 Apr 2019 01:30:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 533D76B0006; Thu, 18 Apr 2019 01:30:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4494D6B0007; Thu, 18 Apr 2019 01:30:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-vs1-f72.google.com (mail-vs1-f72.google.com [209.85.217.72]) by kanga.kvack.org (Postfix) with ESMTP id 1EDDB6B0005 for ; Thu, 18 Apr 2019 01:30:47 -0400 (EDT) Received: by mail-vs1-f72.google.com with SMTP id p134so185615vsc.10 for ; Wed, 17 Apr 2019 22:30:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:mime-version:references :in-reply-to:from:date:message-id:subject:to:cc; bh=bLtDzKXu09gPBmOTPhLlCKa/1j1gZ8w+6fLRYpgkXVc=; b=VP5ajjXpwf829cnlXUNGtUoV4hT+5FiVIlIFkmpkhFVasJ+p9s3yeN5jIAxxzzEE3j OJFjYQg42QDox4wIu0ly4NxMZWwcPLahvzFFRphHo3HfccR3lYW7Qjr0JBBAGR4IJfWs vfUlQjrx3s894TWvgiygkaJdBOR7tJw4NX3Aaz++BJiL0a4rLMc5t2z/mjv2tnCn7gPf wzCBFD6M1lIyqcUWNC9UQS3sW5YNwVXoSovlm3SkRPtzmFaPx731VoDZnq4wLq09qrGO olyKg3Y3Qh//oLsaw0Jf8NjUnp38UL+WnJjBOmCrkPMGnTgcnpDZD/0poUoWhBPMhz0u xu0A== X-Gm-Message-State: APjAAAV8vgpb5OoDVpESj/PpowioTjpF+HscE9ua3eq3oZ9x+EUzO3Ie 0eVx55uZWndLNRsKvrG2SU0M5qxmpQRhdS8G87Pu9eXEBYYukexAzOMchAsNU8M9BOry+24syE4 gUQf5DmUAsUlpt16VHKXF6rjfWwFEWP+YBhEwifLY+lOUvcPZ6QChoNndrwslqHKiJQ== X-Received: by 2002:a67:bc13:: with SMTP id t19mr2610608vsn.222.1555565446852; Wed, 17 Apr 2019 22:30:46 -0700 (PDT) X-Received: by 2002:a67:bc13:: with SMTP id t19mr2610579vsn.222.1555565446100; Wed, 17 Apr 2019 22:30:46 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1555565446; cv=none; d=google.com; s=arc-20160816; b=YycveXxDLZOlZglebp/ZRgEblTVMIJqzACA52UL00l1acy7h3S0xIhGjiNgQTuCXV2 1oH5AuLPtZNH2CyhxBr7Bj5XQZdnIZN6qmvv46F1I7uyccC5wmPEWQzCQysBjKjWn8pf +ZxlXsp6cVaZIqXCb2lKE4XIurdBozL53i2LMqDYFWeowWbw6cvpKg+XfZlcbp9Dexgn CYYqFwlWFY0o83EhKLOlK+tH2vYbo6B6VRVN3MBy3swgp91Xbs/93ZFA2UXbQ1P0TESS qPJCI7+fvPFiEfIwJUwlYseI6KFa0QIUh4ZRk65BOBTI+Zz9HRJIujqzIFHLjvz+KLtR hGxQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:dkim-signature; bh=bLtDzKXu09gPBmOTPhLlCKa/1j1gZ8w+6fLRYpgkXVc=; b=iTiXAsK6BM5l+U0i3d+6/FNGxZZmpB2vNnW9JMPajLN1SBrnoXMc+UomBWa3T0HkOM /+Y1t1vA31KfUocGQ4epVy99O5VIyCF3wY+3w6pXnl4frkO78LMsKcPff642i+bWAqw3 Z+++mepX3gNYChY4Gtf1xIhsYJlWnKCDG3Q2T2yLb6NUfAJxledpQQWZd8nPWZuPF1KJ VcJSNpZzv9AEOGKYQmejU5FA0/nSiRDs57JEuweeO91Sy4P3h3D+WsRSvyNlv2PaUVbQ J9wCi09FvABpuC4Izi/4fn+DjPdcJCws3DB9M1wnFMBf7I1eH0ChvCZ296XZSCzPQLeH FkWQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=edeVbOaB; spf=pass (google.com: domain of keescook@chromium.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=keescook@chromium.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id f1sor515014uao.43.2019.04.17.22.30.46 for (Google Transport Security); Wed, 17 Apr 2019 22:30:46 -0700 (PDT) Received-SPF: pass (google.com: domain of keescook@chromium.org designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=edeVbOaB; spf=pass (google.com: domain of keescook@chromium.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=keescook@chromium.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=bLtDzKXu09gPBmOTPhLlCKa/1j1gZ8w+6fLRYpgkXVc=; b=edeVbOaBMLhN2dBQJXpv+D+6vAjewlRc9kM5lTmzsJMTYvnZuw8u8Y7DqZfh26UEgW OHIgnpHVLQHXols38+FJXscMQV6lYZx93+goYy0WamrsRBkh1x83txAmNxUkD0xqfkb/ 5V9w/CLbuOWB3OiL1UReRwHKvROTO3KbTfB1M= X-Google-Smtp-Source: APXvYqy8idrwo1IybjTLXKjxX3T+Wx8cDqYrZPT3sCnZyVy+TQbXNojIpyUCT8wGz6kQG/3oTk4A2A== X-Received: by 2002:ab0:6704:: with SMTP id q4mr2582684uam.132.1555565444651; Wed, 17 Apr 2019 22:30:44 -0700 (PDT) Received: from mail-vs1-f51.google.com (mail-vs1-f51.google.com. [209.85.217.51]) by smtp.gmail.com with ESMTPSA id l9sm222487uae.1.2019.04.17.22.30.43 for (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Wed, 17 Apr 2019 22:30:43 -0700 (PDT) Received: by mail-vs1-f51.google.com with SMTP id g127so509287vsd.6 for ; Wed, 17 Apr 2019 22:30:43 -0700 (PDT) X-Received: by 2002:a67:e881:: with SMTP id x1mr52185580vsn.48.1555565442783; Wed, 17 Apr 2019 22:30:42 -0700 (PDT) MIME-Version: 1.0 References: <20190417052247.17809-1-alex@ghiti.fr> <20190417052247.17809-9-alex@ghiti.fr> In-Reply-To: <20190417052247.17809-9-alex@ghiti.fr> From: Kees Cook Date: Thu, 18 Apr 2019 00:30:31 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v3 08/11] mips: Properly account for stack randomization and stack guard gap 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 , Kees Cook , LKML , linux-arm-kernel , linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, "linux-fsdevel@vger.kernel.org" , Linux-MM Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Apr 17, 2019 at 12:31 AM Alexandre Ghiti wrote: > > This commit takes care of stack randomization and stack guard gap when > computing mmap base address and checks if the task asked for randomization. > This fixes the problem uncovered and not fixed for mips here: > https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1429066.html same URL change here please... > > Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook -Kees > --- > arch/mips/mm/mmap.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c > index 2f616ebeb7e0..3ff82c6f7e24 100644 > --- a/arch/mips/mm/mmap.c > +++ b/arch/mips/mm/mmap.c > @@ -21,8 +21,9 @@ unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ > EXPORT_SYMBOL(shm_align_mask); > > /* gap between mmap and stack */ > -#define MIN_GAP (128*1024*1024UL) > -#define MAX_GAP ((TASK_SIZE)/6*5) > +#define MIN_GAP (128*1024*1024UL) > +#define MAX_GAP ((TASK_SIZE)/6*5) > +#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) > > static int mmap_is_legacy(struct rlimit *rlim_stack) > { > @@ -38,6 +39,15 @@ static int mmap_is_legacy(struct rlimit *rlim_stack) > static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) > { > unsigned long gap = rlim_stack->rlim_cur; > + unsigned long pad = stack_guard_gap; > + > + /* Account for stack randomization if necessary */ > + if (current->flags & PF_RANDOMIZE) > + pad += (STACK_RND_MASK << PAGE_SHIFT); > + > + /* Values close to RLIM_INFINITY can overflow. */ > + if (gap + pad > gap) > + gap += pad; > > if (gap < MIN_GAP) > gap = MIN_GAP; > -- > 2.20.1 > -- Kees Cook