From patchwork Wed Feb 17 16:10:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeffrey Hugo X-Patchwork-Id: 383970 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=-16.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 3D138C4332D for ; Wed, 17 Feb 2021 16:11:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1156064E45 for ; Wed, 17 Feb 2021 16:11:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234027AbhBQQLv (ORCPT ); Wed, 17 Feb 2021 11:11:51 -0500 Received: from z11.mailgun.us ([104.130.96.11]:19383 "EHLO z11.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234049AbhBQQLm (ORCPT ); Wed, 17 Feb 2021 11:11:42 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1613578278; h=Content-Transfer-Encoding: MIME-Version: Message-Id: Date: Subject: Cc: To: From: Sender; bh=U8Z4sq17MZxEZbn8xWLO7meIIHA9hE8Uv9NohLheFCw=; b=p1xPdoBAIYFusLxsKwRoh5404MZeOmpSfBjRUkfzq4fLBAs9XbTCicCSi5/A9CnPDQ+Z2Xuh S+8oEuj3ay7SU+nIolu+Oo9C4Iezn/Kk1nOfRif4oDUKUcSOjyeU+geoKqj8yCbaqbL5YWeE L58nkcyD3y9CUiMlLi8pBQa1odA= X-Mailgun-Sending-Ip: 104.130.96.11 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 smtp-out-n04.prod.us-east-1.postgun.com with SMTP id 602d4003a294c935b7c220a8 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 17 Feb 2021 16:10:43 GMT Sender: jhugo=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 7AA91C43462; Wed, 17 Feb 2021 16:10:42 +0000 (UTC) Received: from jhugo-lnx.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: jhugo) by smtp.codeaurora.org (Postfix) with ESMTPSA id 337DAC433ED; Wed, 17 Feb 2021 16:10:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 337DAC433ED 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=fail smtp.mailfrom=jhugo@codeaurora.org From: Jeffrey Hugo To: manivannan.sadhasivam@linaro.org, hemantk@codeaurora.org Cc: bbhatt@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Jeffrey Hugo Subject: [PATCH] mhi_bus: core: Sanity check values from remote device before use Date: Wed, 17 Feb 2021 09:10:32 -0700 Message-Id: <1613578232-15229-1-git-send-email-jhugo@codeaurora.org> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org When parsing the structures in the shared memory, there are values which come from the remote device. For example, a transfer completion event will have a pointer to the tre in the relevant channel's transfer ring. Such values should be considered to be untrusted, and validated before use. If we blindly use such values, we may access invalid data or crash if the values are corrupted. If validation fails, drop the relevant event. Signed-off-by: Jeffrey Hugo --- drivers/bus/mhi/core/main.c | 81 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 74 insertions(+), 7 deletions(-) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index c043574..1eb2fd3 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -242,6 +242,11 @@ static void mhi_del_ring_element(struct mhi_controller *mhi_cntrl, smp_wmb(); } +static bool is_valid_ring_ptr(struct mhi_ring *ring, dma_addr_t addr) +{ + return addr >= ring->iommu_base && addr < ring->iommu_base + ring->len; +} + int mhi_destroy_device(struct device *dev, void *data) { struct mhi_device *mhi_dev; @@ -383,7 +388,16 @@ irqreturn_t mhi_irq_handler(int irq_number, void *dev) struct mhi_event_ctxt *er_ctxt = &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index]; struct mhi_ring *ev_ring = &mhi_event->ring; - void *dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp); + dma_addr_t ptr = er_ctxt->rp; + void *dev_rp; + + if (!is_valid_ring_ptr(ev_ring, ptr)) { + dev_err(&mhi_cntrl->mhi_dev->dev, + "Event ring rp points outside of the event ring\n"); + return IRQ_HANDLED; + } + + dev_rp = mhi_to_virtual(ev_ring, ptr); /* Only proceed if event ring has pending events */ if (ev_ring->rp == dev_rp) @@ -536,6 +550,11 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl, struct mhi_buf_info *buf_info; u16 xfer_len; + if (!is_valid_ring_ptr(tre_ring, ptr)) { + dev_err(&mhi_cntrl->mhi_dev->dev, + "Event element points outside of the tre ring\n"); + break; + } /* Get the TRB this event points to */ ev_tre = mhi_to_virtual(tre_ring, ptr); @@ -695,6 +714,12 @@ static void mhi_process_cmd_completion(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan; u32 chan; + if (!is_valid_ring_ptr(mhi_ring, ptr)) { + dev_err(&mhi_cntrl->mhi_dev->dev, + "Event element points outside of the cmd ring\n"); + return; + } + cmd_pkt = mhi_to_virtual(mhi_ring, ptr); chan = MHI_TRE_GET_CMD_CHID(cmd_pkt); @@ -719,6 +744,7 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl, struct device *dev = &mhi_cntrl->mhi_dev->dev; u32 chan; int count = 0; + dma_addr_t ptr = er_ctxt->rp; /* * This is a quick check to avoid unnecessary event processing @@ -728,7 +754,13 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl, if (unlikely(MHI_EVENT_ACCESS_INVALID(mhi_cntrl->pm_state))) return -EIO; - dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp); + if (!is_valid_ring_ptr(ev_ring, ptr)) { + dev_err(&mhi_cntrl->mhi_dev->dev, + "Event ring rp points outside of the event ring\n"); + return -EIO; + } + + dev_rp = mhi_to_virtual(ev_ring, ptr); local_rp = ev_ring->rp; while (dev_rp != local_rp) { @@ -834,6 +866,8 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl, */ if (chan < mhi_cntrl->max_chan) { mhi_chan = &mhi_cntrl->mhi_chan[chan]; + if (!mhi_chan->configured) + break; parse_xfer_event(mhi_cntrl, local_rp, mhi_chan); event_quota--; } @@ -845,7 +879,15 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl, mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring); local_rp = ev_ring->rp; - dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp); + + ptr = er_ctxt->rp; + if (!is_valid_ring_ptr(ev_ring, ptr)) { + dev_err(&mhi_cntrl->mhi_dev->dev, + "Event ring rp points outside of the event ring\n"); + return -EIO; + } + + dev_rp = mhi_to_virtual(ev_ring, ptr); count++; } @@ -868,11 +910,18 @@ int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl, int count = 0; u32 chan; struct mhi_chan *mhi_chan; + dma_addr_t ptr = er_ctxt->rp; if (unlikely(MHI_EVENT_ACCESS_INVALID(mhi_cntrl->pm_state))) return -EIO; - dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp); + if (!is_valid_ring_ptr(ev_ring, ptr)) { + dev_err(&mhi_cntrl->mhi_dev->dev, + "Event ring rp points outside of the event ring\n"); + return -EIO; + } + + dev_rp = mhi_to_virtual(ev_ring, ptr); local_rp = ev_ring->rp; while (dev_rp != local_rp && event_quota > 0) { @@ -886,7 +935,8 @@ int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl, * Only process the event ring elements whose channel * ID is within the maximum supported range. */ - if (chan < mhi_cntrl->max_chan) { + if (chan < mhi_cntrl->max_chan && + mhi_cntrl->mhi_chan[chan].configured) { mhi_chan = &mhi_cntrl->mhi_chan[chan]; if (likely(type == MHI_PKT_TYPE_TX_EVENT)) { @@ -900,7 +950,15 @@ int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl, mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring); local_rp = ev_ring->rp; - dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp); + + ptr = er_ctxt->rp; + if (!is_valid_ring_ptr(ev_ring, ptr)) { + dev_err(&mhi_cntrl->mhi_dev->dev, + "Event ring rp points outside of the event ring\n"); + return -EIO; + } + + dev_rp = mhi_to_virtual(ev_ring, ptr); count++; } read_lock_bh(&mhi_cntrl->pm_lock); @@ -1365,6 +1423,7 @@ static void mhi_mark_stale_events(struct mhi_controller *mhi_cntrl, struct mhi_ring *ev_ring; struct device *dev = &mhi_cntrl->mhi_dev->dev; unsigned long flags; + dma_addr_t ptr; dev_dbg(dev, "Marking all events for chan: %d as stale\n", chan); @@ -1372,7 +1431,15 @@ static void mhi_mark_stale_events(struct mhi_controller *mhi_cntrl, /* mark all stale events related to channel as STALE event */ spin_lock_irqsave(&mhi_event->lock, flags); - dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp); + + ptr = er_ctxt->rp; + if (!is_valid_ring_ptr(ev_ring, ptr)) { + dev_err(&mhi_cntrl->mhi_dev->dev, + "Event ring rp points outside of the event ring\n"); + dev_rp = ev_ring->rp; + } else { + dev_rp = mhi_to_virtual(ev_ring, ptr); + } local_rp = ev_ring->rp; while (dev_rp != local_rp) {