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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 E9E15C6778A for ; Mon, 2 Jul 2018 15:56:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A54222518F for ; Mon, 2 Jul 2018 15:56:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="FggABiQq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A54222518F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org 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 S1752769AbeGBP41 (ORCPT ); Mon, 2 Jul 2018 11:56:27 -0400 Received: from mail-pf0-f193.google.com ([209.85.192.193]:38011 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752209AbeGBP4Y (ORCPT ); Mon, 2 Jul 2018 11:56:24 -0400 Received: by mail-pf0-f193.google.com with SMTP id j17-v6so7711421pfn.5 for ; Mon, 02 Jul 2018 08:56:24 -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:mime-version:content-disposition; bh=7sgR3XWb0ZjhnXliIyW3/K457TTRxSTFst5nLbjcNV8=; b=FggABiQqwWjx5dBkx9/Xc0dLo9ZCFmCWp4XNprXC5r9MTEGWSaQLjjLoI6bxwAEbq/ JpkZ+DT/cN/SPVcc0Sqic0F4+x6gJjdbZ2qEwDTDmC5/ry8T6X95OkqT/GOwADGWDZHi 8uIPegkjPgSR3wtqNiAdF25VnxNdPs3cTy/5Y= 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:mime-version :content-disposition; bh=7sgR3XWb0ZjhnXliIyW3/K457TTRxSTFst5nLbjcNV8=; b=a6wJwhkEU1wnDaAq8MJU4CiUmhskcSulDjafwWJHRcSbPe0TCYIXgUb4a3NVosDRcs neNWbRp56JupGzPDxZNHHerPkdyjgmWfVgWEPDeT/A1g71UnCNwkAHi239lXuE1M92QR fTeY+Vv27omDUHkDJjmkznn4pCuKp57pNaKT3ZPZX5ascX2oAX4kWzhVKXnKcTzFb8oq AKvLcEDir53QBBLZzB9bc+seuHyTaR7yjg04x+yK55KJuDoIFoGyJlY0jCtUsW8xRotD NZY9SxbfUNpZdf01W2lN23JL7EcPKA5bf7yVMpe7KoLnEm2tbYjDPBa4THAKQKsvdNZH 21Lg== X-Gm-Message-State: APt69E0PuGIEnxsvxGBCy6sE0kEPB9E6MPxjljOOmCDdE5XjS3+uokeJ sL+sQPjUMy26AYBOjznZ9LUbAOjcue4= X-Google-Smtp-Source: AAOMgpdUedS5JSPLBHQOIbAFBycB1rD2VZwUQcHr++db/twPxBRfGwHDkdy3yW21y0JHhupq+srRoQ== X-Received: by 2002:a65:6398:: with SMTP id h24-v6mr5576172pgv.245.1530546984098; Mon, 02 Jul 2018 08:56:24 -0700 (PDT) Received: from www.outflux.net (173-164-112-133-Oregon.hfc.comcastbusiness.net. [173.164.112.133]) by smtp.gmail.com with ESMTPSA id b62-v6sm26084830pfj.123.2018.07.02.08.56.22 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 02 Jul 2018 08:56:22 -0700 (PDT) Date: Mon, 2 Jul 2018 08:56:21 -0700 From: Kees Cook To: Michael Ellerman Cc: Arnd Bergmann , Anatolij Gustschin , Benjamin Herrenschmidt , Paul Mackerras , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v2] powerpc: mpc5200: Remove VLA usage Message-ID: <20180702155621.GA16047@beast> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In the quest to remove all stack VLA usage from the kernel[1], this switches to using a stack size large enough for the saved routine and adds a sanity check making sure the routine doesn't overflow into the 0x600 exception handler. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Signed-off-by: Kees Cook Reviewed-by: Arnd Bergmann --- v2: use "0x600-0x500" for size calculation to illustrate handler sizes --- arch/powerpc/platforms/52xx/mpc52xx_pm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pm.c b/arch/powerpc/platforms/52xx/mpc52xx_pm.c index 31d3515672f3..b1d208ded981 100644 --- a/arch/powerpc/platforms/52xx/mpc52xx_pm.c +++ b/arch/powerpc/platforms/52xx/mpc52xx_pm.c @@ -117,7 +117,10 @@ int mpc52xx_pm_enter(suspend_state_t state) u32 intr_main_mask; void __iomem * irq_0x500 = (void __iomem *)CONFIG_KERNEL_START + 0x500; unsigned long irq_0x500_stop = (unsigned long)irq_0x500 + mpc52xx_ds_cached_size; - char saved_0x500[mpc52xx_ds_cached_size]; + char saved_0x500[0x600-0x500]; + + if (WARN_ON(mpc52xx_ds_cached_size > sizeof(saved_0x500))) + return -ENOMEM; /* disable all interrupts in PIC */ intr_main_mask = in_be32(&intr->main_mask); -- 2.17.1 -- Kees Cook Pixel Security