[libvirt] [PATCH] qemu: Actually unshare() iff running as root

[Michal Privoznik]

While all the code that deals with qemu namespaces correctly
detects whether we are running as root (and turn into NO-OP for
qemu:///session) the actual unshare() call is not guarded with
such check. Therefore any attempt to start a domain under
qemu:///session shall fail as unshare() is reserved for root.

The fix consists of moving unshare() call (for which we have a
wrapper called virProcessSetupPrivateMountNS) into
qemuDomainBuildNamespace() where the proper check is performed.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/qemu/qemu_domain.c  | 3 +++
 src/qemu/qemu_process.c | 3 ---
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 35baffb51..c67604222 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -7400,6 +7400,9 @@ qemuDomainBuildNamespace(virQEMUDriverPtr driver,
         goto cleanup;
     }
 
+    if (virProcessSetupPrivateMountNS() < 0)
+        goto cleanup;
+
     if (qemuDomainSetupDev(driver, vm, devPath) < 0)
         goto cleanup;
 
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index a980f5a9e..184440dc1 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -2663,9 +2663,6 @@ static int qemuProcessHook(void *data)
     if (virSecurityManagerClearSocketLabel(h->driver->securityManager, h->vm->def) < 0)
         goto cleanup;
 
-    if (virProcessSetupPrivateMountNS() < 0)
-        goto cleanup;
-
     if (qemuDomainBuildNamespace(h->driver, h->vm) < 0)
         goto cleanup;
 
-- 
2.11.0