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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 A4A35C7618E for ; Tue, 30 Jul 2019 04:58:29 +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 8015C206A2 for ; Tue, 30 Jul 2019 04:58:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8015C206A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com 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 E1BFD237D; Tue, 30 Jul 2019 04:58:21 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 1271121FF for ; Tue, 30 Jul 2019 04:53:32 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id A043BD3 for ; Tue, 30 Jul 2019 04:53:31 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Jul 2019 21:53:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,325,1559545200"; d="scan'208";a="183007158" Received: from allen-box.sh.intel.com ([10.239.159.136]) by orsmga002.jf.intel.com with ESMTP; 29 Jul 2019 21:53:27 -0700 From: Lu Baolu To: David Woodhouse , Joerg Roedel , Bjorn Helgaas , Christoph Hellwig Subject: [PATCH v6 4/8] swiotlb: Zero out bounce buffer for untrusted device Date: Tue, 30 Jul 2019 12:52:25 +0800 Message-Id: <20190730045229.3826-5-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190730045229.3826-1-baolu.lu@linux.intel.com> References: <20190730045229.3826-1-baolu.lu@linux.intel.com> Cc: Juergen Gross , kevin.tian@intel.com, Stefano Stabellini , ashok.raj@intel.com, Konrad Rzeszutek Wilk , alan.cox@intel.com, Jonathan Corbet , Robin Murphy , Steven Rostedt , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, pengfei.xu@intel.com, Ingo Molnar , jacob.jun.pan@intel.com, Greg Kroah-Hartman , Boris Ostrovsky , mika.westerberg@linux.intel.com 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: , MIME-Version: 1.0 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 This is necessary to avoid exposing valid kernel data to any malicious device. Suggested-by: Christoph Hellwig Signed-off-by: Lu Baolu --- kernel/dma/swiotlb.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 89066efa3840..04bea5a87462 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -35,6 +35,7 @@ #include #include #include +#include #ifdef CONFIG_DEBUG_FS #include #endif @@ -458,6 +459,8 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, unsigned long offset_slots; unsigned long max_slots; unsigned long tmp_io_tlb_used; + void *zero_addr; + size_t zero_size; if (no_iotlb_memory) panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); @@ -565,9 +568,20 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, */ for (i = 0; i < nslots; i++) io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT); + + zero_addr = phys_to_virt(tlb_addr); + zero_size = alloc_size; + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && - (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) + (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) { swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE); + zero_addr += mapping_size; + zero_size -= mapping_size; + } + + /* Zero out the bounce buffer if the consumer is untrusted. */ + if (dev_is_untrusted(hwdev) && zero_size) + memset(zero_addr, 0, zero_size); return tlb_addr; } -- 2.17.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu