From e86103a75705c7c530768f4ffaba74cf382910f2 Mon Sep 17 00:00:00 2001 From: Robert Dobrowolski Date: Thu, 24 Mar 2016 03:30:07 -0700 Subject: [PATCH] usb: hcd: out of bounds access in for_each_companion On BXT platform Host Controller and Device Controller figure as same PCI device but with different device function. HCD should not pass data to Device Controller but only to Host Controllers. Checking if companion device is Host Controller, otherwise skip. Cc: Signed-off-by: Robert Dobrowolski Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hcd-pci.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c index f9d42cf23e55..7859d738df41 100644 --- a/drivers/usb/core/hcd-pci.c +++ b/drivers/usb/core/hcd-pci.c @@ -73,6 +73,15 @@ static void for_each_companion(struct pci_dev *pdev, struct usb_hcd *hcd, if (companion->bus != pdev->bus || PCI_SLOT(companion->devfn) != slot) continue; + + /* + * Companion device should be either UHCI,OHCI or EHCI host + * controller, otherwise skip. + */ + if (companion->class != CL_UHCI && companion->class != CL_OHCI && + companion->class != CL_EHCI) + continue; + companion_hcd = pci_get_drvdata(companion); if (!companion_hcd || !companion_hcd->self.root_hub) continue;