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,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 8AD6FC83004 for ; Tue, 28 Apr 2020 03:00:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6532F2073C for ; Tue, 28 Apr 2020 03:00:12 +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="pyr/gKXo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726502AbgD1DAL (ORCPT ); Mon, 27 Apr 2020 23:00:11 -0400 Received: from mail26.static.mailgun.info ([104.130.122.26]:54065 "EHLO mail26.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726373AbgD1C7n (ORCPT ); Mon, 27 Apr 2020 22:59:43 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588042783; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=Mmd869U66bQVoS9PKHfqpcqBXfawxogrkulMYmXxB70=; b=pyr/gKXoIlsfPRqRITNyQ5P7ypr4J/nMV0//TzchZ7xSXZWp4Z5Gj+3z0PoGu2dMrCz9fHW+ n91N/T4pwtFKEMmjYCdESFDr1X+w37qSOpC2xwaEWFv5qHpkEDLrLQjM08X6/GAnn/xE2l3o U472Q+pMLLZT+pMTT97Iu86oRZg= X-Mailgun-Sending-Ip: 104.130.122.26 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 5ea79c1e.7f0f286433b0-smtp-out-n01; Tue, 28 Apr 2020 02:59:42 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id C78A7C43637; Tue, 28 Apr 2020 02:59:41 +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 749A9C43636; Tue, 28 Apr 2020 02:59:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 749A9C43636 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, Bhaumik Bhatt Subject: [PATCH v2 3/8] bus: mhi: core: Read transfer length from an event properly Date: Mon, 27 Apr 2020 19:59:21 -0700 Message-Id: <1588042766-17496-4-git-send-email-bbhatt@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1588042766-17496-1-git-send-email-bbhatt@codeaurora.org> References: <1588042766-17496-1-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 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 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