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=-9.8 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_GIT autolearn=unavailable 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 487DBC3276C for ; Thu, 2 Jan 2020 23:00:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1BA7520848 for ; Thu, 2 Jan 2020 23:00:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578006023; bh=PBHb5ijfB+T3bwG+9x4hokUpoUPYGrSirFzfyZnrxJY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PD8ZpI3orE1Ic9+A4DWUstnhhzqanYdOqQjNwTVoSbSDnPbvjI5BJNBfnGDUpaFun 64gUZm40iF2CzrqZmDkTQZIR0WebbSP6ks7e5aR/uw0sSOVvIFH2LxkBB/rk6Y9pUP BFEPHdUXMSgNEJRGFHog1+a+Vc2TTJqV2PAzVnSw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728222AbgABXAW (ORCPT ); Thu, 2 Jan 2020 18:00:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:52648 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727226AbgABWNF (ORCPT ); Thu, 2 Jan 2020 17:13:05 -0500 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 1F6D721D7D; Thu, 2 Jan 2020 22:13:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578003184; bh=PBHb5ijfB+T3bwG+9x4hokUpoUPYGrSirFzfyZnrxJY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BZT+rDLKybt1uOAMNvSI0/2gZfPqfatkYhUewVfcTTnvR4zPtcYjLxGc1XjCkVQrE LMWryoQW80m6MBL/7spyXRCy/Wd3ItNVw/9TZ2qXfqiHJp8C8VkdchCHFQLsMaeRQ0 bnUYzTCRw6TBah1lM+J4eeazru/ZuhM8X64Luack= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicolas Saenz Julienne , Christoph Hellwig , Sasha Levin Subject: [PATCH 5.4 054/191] dma-direct: check for overflows on 32 bit DMA addresses Date: Thu, 2 Jan 2020 23:05:36 +0100 Message-Id: <20200102215835.696014868@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200102215829.911231638@linuxfoundation.org> References: <20200102215829.911231638@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicolas Saenz Julienne [ Upstream commit b12d66278dd627cbe1ea7c000aa4715aaf8830c8 ] As seen on the new Raspberry Pi 4 and sta2x11's DMA implementation it is possible for a device configured with 32 bit DMA addresses and a partial DMA mapping located at the end of the address space to overflow. It happens when a higher physical address, not DMAable, is translated to it's DMA counterpart. For example the Raspberry Pi 4, configurable up to 4 GB of memory, has an interconnect capable of addressing the lower 1 GB of physical memory with a DMA offset of 0xc0000000. It transpires that, any attempt to translate physical addresses higher than the first GB will result in an overflow which dma_capable() can't detect as it only checks for addresses bigger then the maximum allowed DMA address. Fix this by verifying in dma_capable() if the DMA address range provided is at any point lower than the minimum possible DMA address on the bus. Signed-off-by: Nicolas Saenz Julienne Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- include/linux/dma-direct.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index adf993a3bd58..6a18a97b76a8 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -3,8 +3,11 @@ #define _LINUX_DMA_DIRECT_H 1 #include +#include /* for min_low_pfn */ #include +static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr); + #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA #include #else @@ -24,11 +27,16 @@ static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr) static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) { + dma_addr_t end = addr + size - 1; + if (!dev->dma_mask) return false; - return addr + size - 1 <= - min_not_zero(*dev->dma_mask, dev->bus_dma_mask); + if (!IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && + min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn))) + return false; + + return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_mask); } #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */ -- 2.20.1