From nobody Thu Sep 4 03:32:50 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 AE4E0C6FA82 for ; Tue, 13 Sep 2022 15:32:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232853AbiIMPcp (ORCPT ); Tue, 13 Sep 2022 11:32:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236508AbiIMPb6 (ORCPT ); Tue, 13 Sep 2022 11:31:58 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98B687E820; Tue, 13 Sep 2022 07:40:36 -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 93BE3B80F6F; Tue, 13 Sep 2022 14:33:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C465FC433C1; Tue, 13 Sep 2022 14:33:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1663079585; bh=QVUIIIchCxxeuUgwWdiExksNAQBR6e7xgJ2M8dTQg50=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hEGcNpHHRuXatl3hTBnqi53B16yleG8ua70/oD1toP4s3qBTu+ZEiZjHHDaBlZOY/ 4epYEqPRWho0Tsjtm8XiZS7xxCSrCm6OlFztT1UHe6objRyM2cPkSwFtIJdj65Lcj8 DBhZm/HEmr6KgAmMYQI9hfZIIvsVDJUuwJWd7izU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matthias Kaehlcke , Manivannan Sadhasivam , Johan Hovold , Johan Hovold Subject: [PATCH 4.19 76/79] usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup Date: Tue, 13 Sep 2022 16:07:34 +0200 Message-Id: <20220913140352.554689442@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220913140348.835121645@linuxfoundation.org> References: <20220913140348.835121645@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 From: Johan Hovold commit a872ab303d5ddd4c965f9cd868677781a33ce35a upstream. 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 [ johan: adjust context for 5.4 ] Signed-off-by: Johan Hovold Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/dwc3-qcom.c | 14 +++++++++++++- drivers/usb/dwc3/host.c | 1 + 2 files changed, 14 insertions(+), 1 deletion(-) --- a/drivers/usb/dwc3/dwc3-qcom.c +++ b/drivers/usb/dwc3/dwc3-qcom.c @@ -173,6 +173,14 @@ static int dwc3_qcom_register_extcon(str 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) { @@ -280,7 +288,11 @@ static irqreturn_t qcom_dwc3_resume_irq( 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; --- a/drivers/usb/dwc3/host.c +++ b/drivers/usb/dwc3/host.c @@ -142,4 +142,5 @@ void dwc3_host_exit(struct dwc3 *dwc) phy_remove_lookup(dwc->usb3_generic_phy, "usb3-phy", dev_name(dwc->dev)); platform_device_unregister(dwc->xhci); + dwc->xhci =3D NULL; }