From patchwork Thu Aug 4 15:09:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 12936478 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83B74C25B08 for ; Thu, 4 Aug 2022 15:10:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239736AbiHDPKS (ORCPT ); Thu, 4 Aug 2022 11:10:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239339AbiHDPKE (ORCPT ); Thu, 4 Aug 2022 11:10:04 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3491A5FAC0; Thu, 4 Aug 2022 08:09:58 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id AA537B8256B; Thu, 4 Aug 2022 15:09:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2EB34C4347C; Thu, 4 Aug 2022 15:09:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659625795; bh=OoTOgjpz5JFq6UJf0u64NVueuER3638cyeEWhnzjxUU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JmfxhuYjg1145GVy3MogH8SsRBxtS78xFJ4D0gFXf0HG7VED0UmQzbIg8L4Z9BH97 6DWXHgCtFwwNlBqEWW+1MKcXr2C/2xyR3Z4ReFw+yzJwbs3uNIOidvnYUxCIINcjD/ mAHM9+y9dqv5gweh6PM+GbMRs9Sjm/nJoUcxR5nAeznBdX0d/K/yhstkzRRjXDcZVX OO4tXahmfeNlTIAdNHRWgiO9pwmIWyJaTuiwm7eShthrwY9MQKXL0yCAxJbHet30+9 0u0LRQX47eCYJylOoWUfcpu4z4ijs8Ddc+QA2lwxcy/Egsbd2e9BRDflZXcbPdqtoh TBRceERd6GN3Q== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1oJcUL-00069W-45; Thu, 04 Aug 2022 17:10:17 +0200 From: Johan Hovold To: Greg Kroah-Hartman , Felipe Balbi Cc: Rob Herring , Krzysztof Kozlowski , Andy Gross , Bjorn Andersson , Manivannan Sadhasivam , Konrad Dybcio , Krishna Kurapati , Stephen Boyd , Doug Anderson , "Matthias Kaehlcke" , Pavankumar Kondeti , quic_ppratap@quicinc.com, quic_vpulyala@quicinc.com, linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org Subject: [PATCH v2 4/9] usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup Date: Thu, 4 Aug 2022 17:09:56 +0200 Message-Id: <20220804151001.23612-5-johan+linaro@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220804151001.23612-1-johan+linaro@kernel.org> References: <20220804151001.23612-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The Qualcomm dwc3 runtime-PM implementation checks the xhci platform-device pointer in the wakeup-interrupt handler to determine whether the controller is in host mode and if so triggers a resume. After a role switch in OTG mode the xhci platform-device would have been freed and the next wakeup from runtime suspend would access the freed memory. Note that role switching is executed from a freezable workqueue, which guarantees that the pointer is stable during suspend. Also note that runtime PM has been broken since commit 2664deb09306 ("usb: dwc3: qcom: Honor wakeup enabled/disabled state"), which incidentally also prevents this issue from being triggered. Fixes: a4333c3a6ba9 ("usb: dwc3: Add Qualcomm DWC3 glue driver") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Johan Hovold Reviewed-by: Matthias Kaehlcke Reviewed-by: Manivannan Sadhasivam --- Changes in v2 - new patch drivers/usb/dwc3/dwc3-qcom.c | 14 +++++++++++++- drivers/usb/dwc3/host.c | 1 + 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c index e9364141661b..6884026b9fad 100644 --- a/drivers/usb/dwc3/dwc3-qcom.c +++ b/drivers/usb/dwc3/dwc3-qcom.c @@ -298,6 +298,14 @@ static void dwc3_qcom_interconnect_exit(struct dwc3_qcom *qcom) icc_put(qcom->icc_path_apps); } +/* Only usable in contexts where the role can not change. */ +static bool dwc3_qcom_is_host(struct dwc3_qcom *qcom) +{ + struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3); + + return dwc->xhci; +} + static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom) { struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3); @@ -460,7 +468,11 @@ static irqreturn_t qcom_dwc3_resume_irq(int irq, void *data) if (qcom->pm_suspended) return IRQ_HANDLED; - if (dwc->xhci) + /* + * This is safe as role switching is done from a freezable workqueue + * and the wakeup interrupts are disabled as part of resume. + */ + if (dwc3_qcom_is_host(qcom)) pm_runtime_resume(&dwc->xhci->dev); return IRQ_HANDLED; diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c index f56c30cf151e..f6f13e7f1ba1 100644 --- a/drivers/usb/dwc3/host.c +++ b/drivers/usb/dwc3/host.c @@ -135,4 +135,5 @@ int dwc3_host_init(struct dwc3 *dwc) void dwc3_host_exit(struct dwc3 *dwc) { platform_device_unregister(dwc->xhci); + dwc->xhci = NULL; }