From: Cole Robinson <crobinso@redhat.com>
Date: Thu, 5 Dec 2013 20:03:00 +0000 (-0500)
Subject: qemu: hotplug: Fix double free on USB collision
X-Git-Tag: CVE-2013-6436~96
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5953a73787b50da56e2ee820a8095ccb09c7a79b;p=thirdparty%2Flibvirt.git

qemu: hotplug: Fix double free on USB collision

If we hit a collision, we free the USB device while it is still part
of our temporary USBDeviceList. When the list is unref'd, the device
is free'd again.

Make the initial device freeing dependent on whether it is present
in the temporary list or not.
---

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index bff9e23df5..b7512a71dc 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -1518,7 +1518,10 @@ cleanup:
     }
     if (added)
         virUSBDeviceListSteal(driver->activeUsbHostdevs, usb);
-    virUSBDeviceFree(usb);
+    if (list && usb &&
+        !virUSBDeviceListFind(list, usb) &&
+        !virUSBDeviceListFind(driver->activeUsbHostdevs, usb))
+        virUSBDeviceFree(usb);
     virObjectUnref(list);
     VIR_FREE(devstr);
     return ret;