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=-13.2 required=3.0 tests=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 917F4CA9EC5 for ; Wed, 30 Oct 2019 18:09:29 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6749A2087E for ; Wed, 30 Oct 2019 18:09:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6749A2087E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 32B24AD7; Wed, 30 Oct 2019 18:09:28 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 4E7AEF16 for ; Wed, 30 Oct 2019 18:09:27 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id D703E876 for ; Wed, 30 Oct 2019 18:09:25 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id A18E468B05; Wed, 30 Oct 2019 19:09:21 +0100 (CET) Date: Wed, 30 Oct 2019 19:09:21 +0100 From: Christoph Hellwig To: Greg Kroah-Hartman Subject: Re: [PATCH v4 1/2] dma-mapping: Add vmap checks to dma_map_single() Message-ID: <20191030180921.GB19366@lst.de> References: <20191029213423.28949-1-keescook@chromium.org> <20191029213423.28949-2-keescook@chromium.org> <20191030091849.GA637042@kroah.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191030091849.GA637042@kroah.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Kees Cook , Semmle Security Reports , linux-kernel@vger.kernel.org, Stephen Boyd , iommu@lists.linux-foundation.org, Dan Carpenter , Jesper Dangaard Brouer , Thomas Gleixner , Laura Abbott , Robin Murphy , Christoph Hellwig , Allison Randal X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Wed, Oct 30, 2019 at 10:18:49AM +0100, Greg Kroah-Hartman wrote: > On Tue, Oct 29, 2019 at 02:34:22PM -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..54de3c496407 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 (dev_WARN_ONCE(dev, is_vmalloc_addr(ptr), > > + "wanted %zu bytes mapped in vmalloc\n", size)) { > > + return DMA_MAPPING_ERROR; > > + } > > That's a very odd error string, I know if I saw it for the first time, I > would have no idea what it meant. The USB message at least gives you a > bit more context as to what went wrong and how to fix it. > > How about something like "Memory is not DMA capabable, please fix the > allocation of it to be correct", or "non-dma-able memory was attempted > to be mapped, but this is impossible to to" or something else. I've fixed the message to "rejecting DMA map of vmalloc memory" and applied the patch. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu