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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 3906EC47404 for ; Sat, 5 Oct 2019 07:26:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0B93B2084D for ; Sat, 5 Oct 2019 07:26:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570260383; bh=xFrXVj45JYqwx14emMFIPwY8ZuiE+j2pGgmNe8jT3vk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=1LV+L3/kIqNreEbxo1EHhhSP45A4dZYJ8NskjiJkO4zFjC8cFRzDoZOINeJ/5oJn6 GeY1AjAiSUpXcwKVPwdJMoeWtGCCqv3S/+AEmp+AJjsh0x0fhdjtvVxV1Yu4z68Qh2 hiDmhEn3eUN9A197XC6ydSSoAZaFsjFgVbR1xhaM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727033AbfJEH0W (ORCPT ); Sat, 5 Oct 2019 03:26:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:56640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725927AbfJEH0W (ORCPT ); Sat, 5 Oct 2019 03:26:22 -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 69EF120830; Sat, 5 Oct 2019 07:26:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570260381; bh=xFrXVj45JYqwx14emMFIPwY8ZuiE+j2pGgmNe8jT3vk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=htZNkApCedGQroo8d6Fz6NZ17pKIL5w52kCPF98KRNd3LBUeP4ewyKCqBya09yPc8 rpXlwcINKSgJY87L/3GiNqdVcIsmj2iuryXkw53Exrqk0rK3GBqpZQdTUSjIAzpK7E Mho1CPRlJ4eTErIoDFtt9E5zWoE/LSDwCnYVtNio= Date: Sat, 5 Oct 2019 09:26:18 +0200 From: Greg Kroah-Hartman To: Kees Cook Cc: Robin Murphy , Laura Abbott , linux-kernel@vger.kernel.org, Christoph Hellwig , Marek Szyprowski , Jesper Dangaard Brouer , Allison Randal , Thomas Gleixner , Stephen Boyd , Dan Carpenter , Semmle Security Reports , iommu@lists.linux-foundation.org Subject: Re: [PATCH v2] dma-mapping: Move vmap address checks into dma_map_single() Message-ID: <20191005072618.GA930906@kroah.com> References: <201910041420.F6E55D29A@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201910041420.F6E55D29A@keescook> 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 Fri, Oct 04, 2019 at 02:28:16PM -0700, Kees Cook wrote: > As we've seen from USB and other areas, we need to always do runtime > checks for DMA operating on memory regions that might be remapped. This > moves the existing checks from USB into dma_map_single(), but leaves > the slightly heavier checks as they are. > > Suggested-by: Laura Abbott > Signed-off-by: Kees Cook > --- > v2: Only add is_vmalloc_addr() > v1: https://lore.kernel.org/lkml/201910021341.7819A660@keescook > --- > drivers/usb/core/hcd.c | 8 +------- > include/linux/dma-mapping.h | 7 +++++++ > 2 files changed, 8 insertions(+), 7 deletions(-) > > diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c > index f225eaa98ff8..281568d464f9 100644 > --- a/drivers/usb/core/hcd.c > +++ b/drivers/usb/core/hcd.c > @@ -1410,10 +1410,7 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, > if (hcd->self.uses_pio_for_control) > return ret; > if (hcd_uses_dma(hcd)) { > - if (is_vmalloc_addr(urb->setup_packet)) { > - WARN_ONCE(1, "setup packet is not dma capable\n"); > - return -EAGAIN; > - } else if (object_is_on_stack(urb->setup_packet)) { > + if (object_is_on_stack(urb->setup_packet)) { > WARN_ONCE(1, "setup packet is on stack\n"); > return -EAGAIN; > } > @@ -1479,9 +1476,6 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, > ret = -EAGAIN; > else > urb->transfer_flags |= URB_DMA_MAP_PAGE; > - } else if (is_vmalloc_addr(urb->transfer_buffer)) { > - WARN_ONCE(1, "transfer buffer not dma capable\n"); > - ret = -EAGAIN; > } else if (object_is_on_stack(urb->transfer_buffer)) { > WARN_ONCE(1, "transfer buffer is on stack\n"); > ret = -EAGAIN; > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index 4a1c4fca475a..12dbd07f74f2 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -583,6 +583,13 @@ 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 (WARN_ONCE(is_vmalloc_addr(ptr), > + "%s %s: driver maps %lu bytes from vmalloc area\n", > + dev ? dev_driver_string(dev) : "unknown driver", > + dev ? dev_name(dev) : "unknown device", size)) If you use dev_warn() here you get all of that "unknown driver/device" checking and handling set properly. And it's in the "standard" format that userspace tools know how to check. thanks, greg k-h