--- /dev/null
+From d0d68ca32c3ec05384bc0114da1197921b6f5a4d Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Thu, 4 Aug 2022 17:09:56 +0200
+Subject: usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup
+
+From: Johan Hovold <johan+linaro@kernel.org>
+
+[ 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 <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>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ 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 27ff18aeea266..4f053d9736e30 100644
+--- a/drivers/usb/dwc3/dwc3-qcom.c
++++ b/drivers/usb/dwc3/dwc3-qcom.c
+@@ -296,6 +296,14 @@ 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 void dwc3_qcom_enable_wakeup_irq(int irq)
+ {
+ if (!irq)
+@@ -405,7 +413,11 @@ 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 f56c30cf151e4..f6f13e7f1ba14 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;
+ }
+--
+2.35.1
+