This is a note to let you know that I've just added the patch titled usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-dwc3-qcom-fix-use-after-free-on-runtime-pm-wakeup.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Sep 6 02:12:11 PM CEST 2022 From: Johan Hovold <johan@xxxxxxxxxx> Date: Tue, 6 Sep 2022 14:07:01 +0200 Subject: usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, Johan Hovold <johan+linaro@xxxxxxxxxx>, Matthias Kaehlcke <mka@xxxxxxxxxxxx>, Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> Message-ID: <20220906120702.19219-3-johan@xxxxxxxxxx> From: Johan Hovold <johan+linaro@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx # 4.18 Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220804151001.23612-5-johan+linaro@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> [ johan: adjust context for 5.15 ] Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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; } Patches currently in stable-queue which might be from johan@xxxxxxxxxx are queue-5.15/usb-serial-option-add-support-for-oppo-r11-diag-port.patch queue-5.15/usb-dwc3-disable-usb-core-phy-management.patch queue-5.15/usb-dwc3-qcom-fix-use-after-free-on-runtime-pm-wakeup.patch queue-5.15/usb-dwc3-fix-phy-disable-sequence.patch queue-5.15/usb-serial-cp210x-add-decagon-uca-device-id.patch queue-5.15/usb-serial-option-add-quectel-em060k-modem.patch queue-5.15/usb-serial-option-add-support-for-cinterion-mv32-wa-wb-rmnet-mode.patch queue-5.15/usb-serial-ftdi_sio-add-omron-cs1w-cif31-device-id.patch