The Qualcomm dwc3 glue driver is currently accessing the driver data of the child core device during suspend and on wakeup interrupts. This is clearly a bad idea as the child may not have probed yet or could have been unbound from its driver.
The first such layering violation was part of the initial version of the driver, but this was later made worse when the hack that accesses the driver data of the grand child xhci device to configure the wakeup interrupts was added.
Fixing this properly is not that easily done, so add a sanity check to make sure that the child driver data is non-NULL before dereferencing it for now.
Note that this relies on subtleties like the fact that driver core is making sure that the parent is not suspended while the child is probing.
Reported-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Link: https://lore.kernel.org/all/20230325165217.31069-4-manivannan.sadhasivam@lin... Fixes: d9152161b4bf ("usb: dwc3: Add Qualcomm DWC3 glue layer driver") Fixes: 6895ea55c385 ("usb: dwc3: qcom: Configure wakeup interrupts during suspend") Cc: stable@vger.kernel.org # 3.18: a872ab303d5d: "usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup" Cc: Sandeep Maheswaram quic_c_sanm@quicinc.com Cc: Krishna Kurapati quic_kriskura@quicinc.com Signed-off-by: Johan Hovold johan+linaro@kernel.org --- drivers/usb/dwc3/dwc3-qcom.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c index 959fc925ca7c..79b22abf9727 100644 --- a/drivers/usb/dwc3/dwc3-qcom.c +++ b/drivers/usb/dwc3/dwc3-qcom.c @@ -308,7 +308,16 @@ static void dwc3_qcom_interconnect_exit(struct dwc3_qcom *qcom) /* 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); + struct dwc3 *dwc; + + /* + * FIXME: Fix this layering violation. + */ + dwc = platform_get_drvdata(qcom->dwc3); + + /* Core driver may not have probed yet. */ + if (!dwc) + return false;
return dwc->xhci; }