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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,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 A2714C83004 for ; Wed, 29 Apr 2020 17:30:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F689206C0 for ; Wed, 29 Apr 2020 17:30:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="I+T1vSvo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726830AbgD2Raj (ORCPT ); Wed, 29 Apr 2020 13:30:39 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:37478 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726580AbgD2Rai (ORCPT ); Wed, 29 Apr 2020 13:30:38 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588181438; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=k1LxYJkImQ30ypmeQ6MNMFerbkjFb8uValw6syMj8iM=; b=I+T1vSvopcY/kuugrPH2gPP9lX1r31whd7fFsP7p47TqFJTmI2wG00VbNcNY3LWGJAH4EnQY XKdO9TGhj3hN2FwzmgRoBkaaiNex6lVwnhWcVUSAaTBecCQFN0bKcFhyYT40P5kT1eXa9A5Y O0CxMNuhmCdAk2XRjWJZqn4/F1c= X-Mailgun-Sending-Ip: 104.130.122.27 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5ea9b9ad.7fa23d9e4340-smtp-out-n03; Wed, 29 Apr 2020 17:30:21 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id B3407C433F2; Wed, 29 Apr 2020 17:30:21 +0000 (UTC) Received: from [10.46.162.249] (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: hemantk) by smtp.codeaurora.org (Postfix) with ESMTPSA id E2E9DC433CB; Wed, 29 Apr 2020 17:30:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org E2E9DC433CB Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=hemantk@codeaurora.org Subject: Re: [PATCH v2 3/8] bus: mhi: core: Read transfer length from an event properly To: Jeffrey Hugo , Bhaumik Bhatt , mani@kernel.org Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org References: <1588042766-17496-1-git-send-email-bbhatt@codeaurora.org> <1588042766-17496-4-git-send-email-bbhatt@codeaurora.org> From: Hemant Kumar Message-ID: <967ee378-bac9-32ba-0110-162dfdb71c1a@codeaurora.org> Date: Wed, 29 Apr 2020 10:30:19 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Hi Jeff On 4/28/20 7:50 AM, Jeffrey Hugo wrote: > On 4/27/2020 8:59 PM, Bhaumik Bhatt wrote: >> From: Hemant Kumar >> >> When MHI Driver receives an EOT event, it reads xfer_len from the >> event in the last TRE. The value is under control of the MHI device >> and never validated by Host MHI driver. The value should never be >> larger than the real size of the buffer but a malicious device can >> set the value 0xFFFF as maximum. This causes device to memory > > The device will overflow, or the driver? Done. > >> overflow (both read or write). Fix this issue by reading minimum of >> transfer length from event and the buffer length provided. >> >> Signed-off-by: Hemant Kumar >> Signed-off-by: Bhaumik Bhatt >> --- >>   drivers/bus/mhi/core/main.c | 5 ++++- >>   1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c >> index 1ccd4cc..3d468d9 100644 >> --- a/drivers/bus/mhi/core/main.c >> +++ b/drivers/bus/mhi/core/main.c >> @@ -521,7 +521,10 @@ static int parse_xfer_event(struct mhi_controller >> *mhi_cntrl, >>                   mhi_cntrl->unmap_single(mhi_cntrl, buf_info); >>               result.buf_addr = buf_info->cb_buf; >> -            result.bytes_xferd = xfer_len; >> + >> +            /* truncate to buf len if xfer_len is larger */ >> +            result.bytes_xferd = >> +                min_t(u16, xfer_len, buf_info->len); >>               mhi_del_ring_element(mhi_cntrl, buf_ring); >>               mhi_del_ring_element(mhi_cntrl, tre_ring); >>               local_rp = tre_ring->rp; >> > > -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project