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 5.19-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-wakeu.patch
and it can be found in the queue-5.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8dbc16b2e11c068a35bba2575b9c8e61b82ac2c0
Author: Johan Hovold <johan+linaro@xxxxxxxxxx>
Date: Thu Aug 4 17:09:56 2022 +0200
usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup
[ 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@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>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index be2e3dd36440..b0ae73b0b1a1 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -298,6 +298,14 @@ 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 enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom)
{
struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
@@ -457,7 +465,11 @@ 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 06b3d988fbf3..a7154fe8206d 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -145,4 +145,5 @@ int dwc3_host_init(struct dwc3 *dwc)
void dwc3_host_exit(struct dwc3 *dwc)
{
platform_device_unregister(dwc->xhci);
+ dwc->xhci = NULL;
}
