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=-13.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 7EA8CC47404 for ; Fri, 11 Oct 2019 05:02:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4BCA62196E for ; Fri, 11 Oct 2019 05:02:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570770135; bh=gL4yGj0SioGU1fefwakreiUM7DxKSrIrbCHtwBEgApM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=fVlsPQ4NwSH4iETX+ngXLsTnPXabHHkk1rEMnLTUElCTF64f49HTQVX6YmU8XzNss V3d/JRx5UsczMni8UL9rR67Sl/0BGWBj7R1keuWVlEKAFqIFyI/vBlpLlvzsQNF/RP J/X75qfAr8cK8SWTQubeXI8uvX3R44BGkehrZ7yo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726559AbfJKFCN (ORCPT ); Fri, 11 Oct 2019 01:02:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:58592 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726108AbfJKFCN (ORCPT ); Fri, 11 Oct 2019 01:02:13 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6C878214E0; Fri, 11 Oct 2019 05:02:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570770130; bh=gL4yGj0SioGU1fefwakreiUM7DxKSrIrbCHtwBEgApM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=boAOtvmCgRi3utYxVgbaKp/aOrYMOXLTUoZ4+SDlZRQ4FMEhDMiOXkGQLIcbmLvOM nGxxJ4yX4yyVDd60TH67Coyw5iTm3Dl3MbKo0pN2023VfERjvxVFX4wk8/c8ij47mq O68rooK6BtpQmjGir5uykiTv931nWb+IR8x70CYQ= Date: Fri, 11 Oct 2019 07:02:08 +0200 From: Greg Kroah-Hartman To: Kees Cook Cc: Christoph Hellwig , Robin Murphy , Laura Abbott , Marek Szyprowski , Jesper Dangaard Brouer , Allison Randal , Thomas Gleixner , Stephen Boyd , Dan Carpenter , Semmle Security Reports , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/2] dma-mapping: Add vmap checks to dma_map_single() Message-ID: <20191011050208.GA978459@kroah.com> References: <20191010222829.21940-1-keescook@chromium.org> <20191010222829.21940-2-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191010222829.21940-2-keescook@chromium.org> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 10, 2019 at 03:28:28PM -0700, Kees Cook wrote: > As we've seen from USB and other areas[1], we need to always do runtime > checks for DMA operating on memory regions that might be remapped. This > adds vmap checks (similar to those already in USB but missing in other > places) into dma_map_single() so all callers benefit from the checking. > > [1] https://git.kernel.org/linus/3840c5b78803b2b6cc1ff820100a74a092c40cbb > > Suggested-by: Laura Abbott > Signed-off-by: Kees Cook > --- > include/linux/dma-mapping.h | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index 4a1c4fca475a..ff4e91c66f44 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -583,6 +583,12 @@ static inline unsigned long dma_get_merge_boundary(struct device *dev) > static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr, > size_t size, enum dma_data_direction dir, unsigned long attrs) > { > + /* DMA must never operate on areas that might be remapped. */ > + if (unlikely(is_vmalloc_addr(ptr))) { > + dev_warn_once(dev, "bad map: %zu bytes in vmalloc\n", size); Can we get a bit better error text here? In USB we were at least giving people a hint as to what went wrong, "bad map" might not really make that much sense to a USB developer as to what they needed to do to fix this issue. Other than that minor nit, I have no objection to this series, thanks for fixing this up! greg k-h