usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup
authorJohan Hovold <johan+linaro@kernel.org>
Thu, 4 Aug 2022 15:09:56 +0000 (17:09 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 18 Aug 2022 17:33:40 +0000 (19:33 +0200)
commita872ab303d5ddd4c965f9cd868677781a33ce35a
tree18e875aa23f1e9d05c81f0a24f9b6c94768a33ee
parentc06795f114a6c4a423b11c9d9bbeb77ecbfbaa8b
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>
drivers/usb/dwc3/dwc3-qcom.c
drivers/usb/dwc3/host.c