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=-13.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 C117ACA9EAF for ; Wed, 30 Oct 2019 09:18:56 +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 9450E2087E for ; Wed, 30 Oct 2019 09:18:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="2PfK0xiK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9450E2087E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org 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 6B568DAF; Wed, 30 Oct 2019 09:18:56 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 8310CDA3 for ; Wed, 30 Oct 2019 09:18:54 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 97DF28A for ; Wed, 30 Oct 2019 09:18:52 +0000 (UTC) Received: from localhost (unknown [91.217.168.176]) (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 C9C35205ED; Wed, 30 Oct 2019 09:18:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572427132; bh=l0MLxBZudc4uU+Zxyk/+94yM1uRPca1KLUiWb6F2o58=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=2PfK0xiKm+k8UGwS7o+AjImlguwO/u1yygHJq2jWEkrnR2I7gKWoYyd21R9E1ZTOS kzo/VJaajX15U/EN/K+CsybbiwRRr0ynjwi885L7Lv4l3W/96gnfDy9SC/bOD3vsUA xrADAi7umiQKJMjunQZzIbjjCZQ25qTEmxZUGJKo= Date: Wed, 30 Oct 2019 10:18:49 +0100 From: Greg Kroah-Hartman To: Kees Cook Subject: Re: [PATCH v4 1/2] dma-mapping: Add vmap checks to dma_map_single() Message-ID: <20191030091849.GA637042@kroah.com> References: <20191029213423.28949-1-keescook@chromium.org> <20191029213423.28949-2-keescook@chromium.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191029213423.28949-2-keescook@chromium.org> User-Agent: Mutt/1.12.2 (2019-09-21) Cc: 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 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. thanks, greg k-h _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu