The patch below does not apply to the 5.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a872ab303d5ddd4c965f9cd868677781a33ce35a Mon Sep 17 00:00:00 2001 From: Johan Hovold johan+linaro@kernel.org Date: Thu, 4 Aug 2022 17:09:56 +0200 Subject: [PATCH] usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup
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 mka@chromium.org Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Signed-off-by: Johan Hovold johan+linaro@kernel.org Link: https://lore.kernel.org/r/20220804151001.23612-5-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
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; }