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 2654AECAAD5 for ; Tue, 6 Sep 2022 14:18:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241270AbiIFOR7 (ORCPT ); Tue, 6 Sep 2022 10:17:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240735AbiIFOPa (ORCPT ); Tue, 6 Sep 2022 10:15:30 -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 7C5017C324; Tue, 6 Sep 2022 06:49:16 -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 1509E61523; Tue, 6 Sep 2022 13:49:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6D7B7C43141; Tue, 6 Sep 2022 13:49:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662472155; bh=B5YKUCOzQi2LrJLBX04dkj5OJAWXgvR0YM6hsEw03Hw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W2zsPFBK72ldlrkJxsFKBDNrjpkTK+zbAj6Hth26FGXSWBugwXLrJtjCoT0xkFnW6 71NBCCRY3oRp5LHpEKgMk0Rq624R7WQer994mZaMlmk8bIuHSgv7NVux0UIRxcZP20 lluxcyY+NRy+mNbUk/bp6RVunl0zu7pNVuVigEfFitxZVKBmstPpsXkJZsvFqwzUHy qFFSC0oUP6SLNG1YisjvqB2wasVxXltEr6H0bkIBRHvNLGSHboQ9OiKAzOCYq4SsY8 hYLTLzUCqGdVpdF7H3LPAQ3MHI2Lgfi2Zekalyu5adzqaFUn7RQknjoSJI3LQsQrBf TFmKqT4qbjgMQ== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1oVYx5-00050S-GA; Tue, 06 Sep 2022 15:49:19 +0200 From: Johan Hovold To: Greg Kroah-Hartman Cc: stable@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , Matthias Kaehlcke , Manivannan Sadhasivam , Johan Hovold Subject: [PATCH stable-4.19 2/4] usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup Date: Tue, 6 Sep 2022 15:49:13 +0200 Message-Id: <20220906134915.19225-3-johan@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220906134915.19225-1-johan@kernel.org> References: <20220906134915.19225-1-johan@kernel.org> MIME-Version: 1.0 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 5.4 ] Signed-off-by: Johan Hovold Signed-off-by: Johan Hovold --- 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 5bb5384f3612..9d5320562e81 100644 --- a/drivers/usb/dwc3/dwc3-qcom.c +++ b/drivers/usb/dwc3/dwc3-qcom.c @@ -173,6 +173,14 @@ static int dwc3_qcom_register_extcon(struct dwc3_qcom *qcom) return 0; } +/* 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) { @@ -280,7 +288,11 @@ 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 1a3878a3be78..124e9f80dccd 100644 --- 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 = NULL; } -- 2.35.1