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=-9.5 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_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 EF173C47254 for ; Tue, 5 May 2020 22:47:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C64AD2073B for ; Tue, 5 May 2020 22:47:54 +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="h15OdQJG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729579AbgEEWru (ORCPT ); Tue, 5 May 2020 18:47:50 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:35745 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729265AbgEEWrk (ORCPT ); Tue, 5 May 2020 18:47:40 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588718859; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=L9nUz4QcIV4087LWk9ngQ8J3kGqbHnK2hICsHkNIRUU=; b=h15OdQJGW+shbMcsqD+ZpThrAYFyWdwCBVPpGL+euaj9cb3EOd1pmBElQ9pK9/kFkPuzvkk6 haFZm8XOAq3d9BGyE/PlWR/cXe5+y5+OOijwHgeXIXVOePtXQew8THHeoxkTS+eeVeNadqK3 frZngRtMN9royiioRoR9Xua+Ay0= X-Mailgun-Sending-Ip: 104.130.122.27 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd 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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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