Fix path used for USB device attach with LXC

The LXC code missed the 'usb' component out of the path
/dev/bus/usb/$BUSNUM/$DEVNUM, so it failed to actually
setup cgroups for the device. This was in fact lucky
because the call to virLXCSetupHostUsbDeviceCgroup
was also mistakenly passing '&priv->cgroup' instead of
just 'priv->cgroup'. So once the path is fixed, libvirtd
would then crash trying to access the bogus virCgroupPtr
pointer. This would have been a security issue, were it
not for the bogus path preventing the pointer reference
being reached.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
index f735631d4526ef33d67742f898dd7e5af08432c1..a381cbd29525c8da58a874aebedd8095c06aa25b 100644 (file)
--- a/src/lxc/lxc_driver.c
+++ b/src/lxc/lxc_driver.c
@@ -3933,7 +3933,7 @@ lxcDomainAttachDeviceHostdevSubsysUSBLive(virLXCDriverPtr driver,
                     (unsigned long long)priv->initpid) < 0)
         goto cleanup;
 
-    if (virAsprintf(&dstdir, "%s/dev/bus/%03d",
+    if (virAsprintf(&dstdir, "%s/dev/bus/usb/%03d",
                     vroot,
                     def->source.subsys.u.usb.bus) < 0)
         goto cleanup;
@@ -3998,7 +3998,7 @@ lxcDomainAttachDeviceHostdevSubsysUSBLive(virLXCDriverPtr driver,
 
     if (virUSBDeviceFileIterate(usb,
                                 virLXCSetupHostUsbDeviceCgroup,
-                                &priv->cgroup) < 0)
+                                priv->cgroup) < 0)
         goto cleanup;
 
     ret = 0;