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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8B19C6FA89 for ; Tue, 6 Sep 2022 13:43:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238777AbiIFNnd (ORCPT ); Tue, 6 Sep 2022 09:43:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234120AbiIFNlW (ORCPT ); Tue, 6 Sep 2022 09:41:22 -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 D266E7DF75; Tue, 6 Sep 2022 06:37:29 -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 B428F6154B; Tue, 6 Sep 2022 13:35:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B530BC433C1; Tue, 6 Sep 2022 13:35:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662471345; bh=o31RZ0FSPNoaHT8CN+G8PmbffRQDGmpmv7Z42yZluC8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1LgkqYSAiIY4FRhNp2nQytsMrGFZl59FAK3IsRwzDn5y9/Rx/ihnTx2GfbnFJPPeS jeIP6sfeLLiJKbW94ROlrimaJBIe9L2W9A4g3IPw2mICjJxx1Kme4C80viIxg/XwG9 x2bnzC7jtztvQ5GRmXa9gRHjXUOMWMstyVVcELjw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matthias Kaehlcke , Manivannan Sadhasivam , Johan Hovold Subject: [PATCH 5.10 77/80] usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup Date: Tue, 6 Sep 2022 15:31:14 +0200 Message-Id: <20220906132820.336028002@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220906132816.936069583@linuxfoundation.org> References: <20220906132816.936069583@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 5.15 ] 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 @@ -296,6 +296,14 @@ static void dwc3_qcom_interconnect_exit( 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 void dwc3_qcom_disable_interrupts(struct dwc3_qcom *qcom) { if (qcom->hs_phy_irq) { @@ -411,7 +419,11 @@ static irqreturn_t qcom_dwc3_resume_irq( 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; --- a/drivers/usb/dwc3/host.c +++ b/drivers/usb/dwc3/host.c @@ -130,4 +130,5 @@ err: void dwc3_host_exit(struct dwc3 *dwc) { platform_device_unregister(dwc->xhci); + dwc->xhci = NULL; }