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=-9.6 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,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 08A6FC47254 for ; Tue, 5 May 2020 22:47:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D842C206B8 for ; Tue, 5 May 2020 22:47:38 +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="cpHvB1gw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729247AbgEEWri (ORCPT ); Tue, 5 May 2020 18:47:38 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:11295 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729293AbgEEWrh (ORCPT ); Tue, 5 May 2020 18:47:37 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588718857; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=L9nUz4QcIV4087LWk9ngQ8J3kGqbHnK2hICsHkNIRUU=; b=cpHvB1gwhUeNb/uGy3frtNvqwX40Ca/6jLFi7aqBSh2uIFgH3PJBeg0OIOBZvhuGKDuIoiWs Ab7sGj2jQc98c3kBIg0sdpaI1NL0t/tEwPabW0L93Y4mJtOXpeL8alyXRU5pdjUOicS5maLj 1l0E6toEaR3+E2omcSscUwlKwvM= 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 5eb1ecfa.7f7933fb4378-smtp-out-n03; Tue, 05 May 2020 22:47:22 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 664E3C4478C; Tue, 5 May 2020 22:47:22 +0000 (UTC) Received: from bbhatt-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: bbhatt) by smtp.codeaurora.org (Postfix) with ESMTPSA id D32BEC43637; Tue, 5 May 2020 22:47:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D32BEC43637 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=bbhatt@codeaurora.org From: Bhaumik Bhatt To: mani@kernel.org Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, hemantk@codeaurora.org, jhugo@codeaurora.org, Bhaumik Bhatt Subject: [PATCH v6 4/8] bus: mhi: core: Read transfer length from an event properly Date: Tue, 5 May 2020 15:47:08 -0700 Message-Id: <1588718832-4891-5-git-send-email-bbhatt@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1588718832-4891-1-git-send-email-bbhatt@codeaurora.org> References: <1588718832-4891-1-git-send-email-bbhatt@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org 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 driver to memory 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 Reviewed-by: Jeffrey Hugo --- drivers/bus/mhi/core/main.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index e60ab21..159732e 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -514,7 +514,10 @@ 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; @@ -598,7 +601,9 @@ static int parse_rsc_event(struct mhi_controller *mhi_cntrl, result.transaction_status = (ev_code == MHI_EV_CC_OVERFLOW) ? -EOVERFLOW : 0; - 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); result.buf_addr = buf_info->cb_buf; result.dir = mhi_chan->dir; -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project