From patchwork Wed Apr 22 04:19:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bhaumik Bhatt X-Patchwork-Id: 11502841 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 719FD92C for ; Wed, 22 Apr 2020 04:20:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 594232076E for ; Wed, 22 Apr 2020 04:20:16 +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="v8iQQC30" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726436AbgDVEUP (ORCPT ); Wed, 22 Apr 2020 00:20:15 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:35344 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726413AbgDVEUD (ORCPT ); Wed, 22 Apr 2020 00:20:03 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1587529203; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=MHoovFjqIgRjM0iNs1686zpLeAHruEipp19zTMHZoiI=; b=v8iQQC30H2Mm8eChrOJsQZnRo/YQ8Ut/N8+ReWhh6vNAeXTuW11firVW8bXuz3R3wiVM8Pm6 iOYXEW0RZ27iVl3aYncx1giAs+YsjTkCEqOvYZUcTAxS+c6BG5SQKk4HHY7fM9uV1UZ1Y+5n 4YOy+ZMQs2aFKjso0Bhg6/+WH90= 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 5e9fc5e8.7f003bbc3998-smtp-out-n01; Wed, 22 Apr 2020 04:19:52 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 3D72CC4478C; Wed, 22 Apr 2020 04:19:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=2.0 tests=ALL_TRUSTED,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.0 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 6AC8BC432C2; Wed, 22 Apr 2020 04:19:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 6AC8BC432C2 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: linux-arm-msm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Hemant Kumar Subject: [PATCH v1 3/8] bus: mhi: core: Read transfer length from an event properly Date: Tue, 21 Apr 2020 21:19:30 -0700 Message-Id: <1587529175-27778-4-git-send-email-bbhatt@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1587529175-27778-1-git-send-email-bbhatt@codeaurora.org> References: <1587529175-27778-1-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 device 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 --- drivers/bus/mhi/core/main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index ba8afa7..3802d3b 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -521,7 +521,8 @@ 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; + 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;