On Tue, Sep 06, 2022 at 02:07:01PM +0200, Johan Hovold wrote:
From: Johan Hovold johan+linaro@kernel.org
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 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 [ johan: adjust context for 5.15 ] Signed-off-by: Johan Hovold johan+linaro@kernel.org
drivers/usb/dwc3/dwc3-qcom.c | 14 +++++++++++++- drivers/usb/dwc3/host.c | 1 + 2 files changed, 14 insertions(+), 1 deletion(-)
This one did not apply to 5.4.y or 4.19.y :(