[libvirt] [PATCH] lxc: don't try to reference NULL when mounting filesystems

[Daniel P. Berrange]

  <filesystem type='ram' accessmode='passthrough'>
    <source usage='524288' units='KiB'/>
    <target dir='/dev/shm'/>
  </filesystem>

would lead to lxcContainerMountAllFS calling STRPREFIX
on a NLL pointer because it failed to check if fs->src->path
was non-NULL. This is a regression caused by

  commit da665fbd4858890fbb3bbf5da2a7b6ca37bb3220
  Author: Olga Krishtal <okrishtal at virtuozzo.com>
  Date:   Thu Jul 14 16:52:38 2016 +0300

    filesystem: adds possibility to use storage pool as fs source

    Signed-off-by: Olga Krishtal <okrishtal at virtuozzo.com>

Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
---
 src/lxc/lxc_container.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
index e1eb434..5357df4 100644
--- a/src/lxc/lxc_container.c
+++ b/src/lxc/lxc_container.c
@@ -1627,8 +1627,7 @@ static int lxcContainerMountAllFS(virDomainDefPtr vmDef,
         if (lxcContainerResolveSymlinks(vmDef->fss[i], false) < 0)
             return -1;
 
-
-        if (!(vmDef->fss[i]->src &&
+        if (!(vmDef->fss[i]->src && vmDef->fss[i]->src->path &&
               STRPREFIX(vmDef->fss[i]->src->path, vmDef->fss[i]->dst)) &&
             lxcContainerUnmountSubtree(vmDef->fss[i]->dst, false) < 0)
             return -1;
-- 
2.7.4