From: Robert Dobrowolski <robert.dobrowolski@linux.intel.com>
Date: Thu, 24 Mar 2016 10:30:07 +0000 (-0700)
Subject: usb: hcd: out of bounds access in for_each_companion
X-Git-Tag: v4.1.23~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b016f99b40071aed628a24d08c61960fd77e553e;p=thirdparty%2Fkernel%2Fstable.git

usb: hcd: out of bounds access in for_each_companion

[ Upstream commit e86103a75705c7c530768f4ffaba74cf382910f2 ]

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: <stable@vger.kernel.org>
Signed-off-by: Robert Dobrowolski <robert.dobrowolski@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---

diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index 9eb1cff28bd4b..b8b580e5ae6e3 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -74,6 +74,15 @@ 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;