[libvirt] [PATCH] apparmor: avoid copying empty profile name

[Jim Fehlig]

AppArmorGetSecurityProcessLabel copies the VM's profile name to the
label member of virSecurityLabel struct. If the profile is not loaded,
the name is set empty before calling virStrcpy to copy it. However,
virStrcpy will fail if src is empty (0 length), causing
AppArmorGetSecurityProcessLabel to needlessly fail. Simple operations
that report security driver information will subsequently fail

virsh dominfo test
Id:             248
Name:           test
...
Security model: apparmor
Security DOI:   0
error: internal error: error copying profile name

Avoid copying an empty profile name when the profile is not loaded.

Signed-off-by: Jim Fehlig <jfehlig at suse.com>
---
 src/security/security_apparmor.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/security/security_apparmor.c b/src/security/security_apparmor.c
index 6d16b15c65..77eee9410c 100644
--- a/src/security/security_apparmor.c
+++ b/src/security/security_apparmor.c
@@ -525,14 +525,13 @@ AppArmorGetSecurityProcessLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
                        "%s", _("error getting profile status"));
         goto cleanup;
     } else if (status == -1) {
-        profile_name[0] = '\0';
-    }
-
-    if (virStrcpy(sec->label, profile_name,
-        VIR_SECURITY_LABEL_BUFLEN) < 0) {
-        virReportError(VIR_ERR_INTERNAL_ERROR,
-                       "%s", _("error copying profile name"));
-        goto cleanup;
+        sec->label[0] = '\0';
+    } else {
+        if (virStrcpy(sec->label, profile_name, VIR_SECURITY_LABEL_BUFLEN) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           "%s", _("error copying profile name"));
+            goto cleanup;
+        }
     }
 
     sec->enforcing = status == 1;
-- 
2.23.0