From nobody Mon Sep 8 08:49:24 2025 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 C4D59C54EE9 for ; Tue, 13 Sep 2022 14:57:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234852AbiIMO5k (ORCPT ); Tue, 13 Sep 2022 10:57:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235057AbiIMOzG (ORCPT ); Tue, 13 Sep 2022 10:55:06 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4EDD967455; Tue, 13 Sep 2022 07:27:27 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 8DBF0614AA; Tue, 13 Sep 2022 14:27:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9815DC433C1; Tue, 13 Sep 2022 14:27:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1663079243; bh=YLvaDxd/FE79/q/Iy23pWP/PXEWDZnOJVJRIS3CaBTU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BPkzLSzH1HycxLkA0Ho+CcccvprpR27smPpC82k9PeNMKfmxgVI6IaN56YNN8EMBy R+a+LTb2DLN0NVB1pMvyTeOx7+ANYTmM5VTwEekMjD6bsCbCWcYyzGJYRZhipRhfiu IIHqnOzjdcv/83cjYeqMx90GLq3ZdMRjmN4z1Sbk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matthias Kaehlcke , Manivannan Sadhasivam , Johan Hovold , Sasha Levin Subject: [PATCH 5.4 032/108] usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup Date: Tue, 13 Sep 2022 16:06:03 +0200 Message-Id: <20220913140355.026878071@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220913140353.549108748@linuxfoundation.org> References: <20220913140353.549108748@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Johan Hovold [ Upstream commit a872ab303d5ddd4c965f9cd868677781a33ce35a ] 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 Reviewed-by: Matthias Kaehlcke Reviewed-by: Manivannan Sadhasivam Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20220804151001.23612-5-johan+linaro@kernel.= org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- 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 7874b97e33227..aed35276e0e0c 100644 --- a/drivers/usb/dwc3/dwc3-qcom.c +++ b/drivers/usb/dwc3/dwc3-qcom.c @@ -190,6 +190,14 @@ static int dwc3_qcom_register_extcon(struct dwc3_qcom = *qcom) return 0; } =20 +/* Only usable in contexts where the role can not change. */ +static bool dwc3_qcom_is_host(struct dwc3_qcom *qcom) +{ + struct dwc3 *dwc =3D platform_get_drvdata(qcom->dwc3); + + return dwc->xhci; +} + static void dwc3_qcom_disable_interrupts(struct dwc3_qcom *qcom) { if (qcom->hs_phy_irq) { @@ -297,7 +305,11 @@ static irqreturn_t qcom_dwc3_resume_irq(int irq, void = *data) if (qcom->pm_suspended) return IRQ_HANDLED; =20 - 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); =20 return IRQ_HANDLED; diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c index fa252870c926f..38bcb079ffc74 100644 --- a/drivers/usb/dwc3/host.c +++ b/drivers/usb/dwc3/host.c @@ -128,4 +128,5 @@ int dwc3_host_init(struct dwc3 *dwc) void dwc3_host_exit(struct dwc3 *dwc) { platform_device_unregister(dwc->xhci); + dwc->xhci =3D NULL; } --=20 2.35.1