From 36ac6e37bec9c2b7043ca9f78386fca1f73de0c0 Mon Sep 17 00:00:00 2001
From: John Ferlan <jferlan@redhat.com>
Date: Mon, 7 Jan 2013 12:09:33 -0500
Subject: [PATCH] lxc: Avoid possible NULL dereference on *root prior to
 opendir().

If running on older Linux without mounted cgroups then its possible that
*root would be NULL.
---
 src/lxc/lxc_container.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
index d3a2968d3b..d234426ff8 100644
--- a/src/lxc/lxc_container.c
+++ b/src/lxc/lxc_container.c
@@ -1762,6 +1762,12 @@ static int lxcContainerIdentifyCGroups(struct lxcContainerCGroup **mountsret,
         VIR_DEBUG("Grabbed '%s'", mntent.mnt_dir);
     }
 
+    if (!*root) {
+        VIR_DEBUG("No mounted cgroups found");
+        ret = 0;
+        goto cleanup;
+    }
+
     VIR_DEBUG("Checking for symlinks in %s", *root);
     if (!(dh = opendir(*root))) {
         virReportSystemError(errno,