From patchwork Wed Apr 29 20:52:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bhaumik Bhatt X-Patchwork-Id: 11518387 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 1686892C for ; Wed, 29 Apr 2020 20:52:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F2C56214AF for ; Wed, 29 Apr 2020 20:52:53 +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="Hdf6TXEV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727097AbgD2Uwx (ORCPT ); Wed, 29 Apr 2020 16:52:53 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:45492 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727119AbgD2Uwr (ORCPT ); Wed, 29 Apr 2020 16:52:47 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588193567; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=qRdYWMIAcK9FRaoesTP+Q+KhDEjeUPFIsX7HKgjdxQ8=; b=Hdf6TXEVj63m9dlG1Bfj7spbz0y0Iuh0Mq5Sir70nkaoYXaz0iPv5ItionbspisHlA5pxk2K QKdOzvb1K5Q9eb2vVAKfR7z9n/f+gxx6uKsCtBmlmAqDatQNuDlHd4k8XZHaGV+XS4dnfqji FIVcNtLrgh40Mr98cULm2fOVq6c= 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 5ea9e918.7f5a2d5d9ab0-smtp-out-n05; Wed, 29 Apr 2020 20:52:40 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 80ABBC433F2; Wed, 29 Apr 2020 20:52:39 +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=ham 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 F02A0C4478C; Wed, 29 Apr 2020 20:52:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org F02A0C4478C 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 v3 4/9] bus: mhi: core: Read transfer length from an event properly Date: Wed, 29 Apr 2020 13:52:26 -0700 Message-Id: <1588193551-31439-5-git-send-email-bbhatt@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1588193551-31439-1-git-send-email-bbhatt@codeaurora.org> References: <1588193551-31439-1-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 | 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 b8e4aac..0afbaa1 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;