qemu_process: Release domain seclabel later in qemuProcessStop()

Some secdrivers (typically SELinux driver) generate unique
dynamic seclabel for each domain (unless a static one is
requested in domain XML). This is achieved by calling
qemuSecurityGenLabel() from qemuProcessPrepareDomain() which
allocates unique seclabel and stores it in domain def->seclabels.
The counterpart is qemuSecurityReleaseLabel() which releases the
label and removes it from def->seclabels. Problem is, that with
current code the qemuProcessStop() may still want to use the
seclabel after it was released, e.g. when it wants to restore the
label of a disk mirror.

What is happening now, is that in qemuProcessStop() the
qemuSecurityReleaseLabel() is called, which removes the SELinux
seclabel from def->seclabels, yada yada yada and eventually
qemuSecurityRestoreImageLabel() is called. This bubbles down to
virSecuritySELinuxRestoreImageLabelSingle() which find no SELinux
seclabel (using virDomainDefGetSecurityLabelDef()) and this
returns early doing nothing.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1751664
Fixes: 8fa0374c5b8e834fcbdeae674cc6cc9e6bf9019f
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 69c517f7a9d0ba1ca1f7eb01fe672cca8b1c44d6..f0a698ba3d85104a850b495c54c68bf23707386c 100644 (file)
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -7707,8 +7707,6 @@ void qemuProcessStop(virQEMUDriverPtr driver,
         qemuSecurityRestoreAllLabel(driver, vm,
                                     !!(flags & VIR_QEMU_PROCESS_STOP_MIGRATED));
 
-    qemuSecurityReleaseLabel(driver->securityManager, vm->def);
-
     for (i = 0; i < vm->def->ndisks; i++) {
         virDomainDeviceDef dev;
         virDomainDiskDefPtr disk = vm->def->disks[i];
@@ -7896,6 +7894,8 @@ void qemuProcessStop(virQEMUDriverPtr driver,
         }
     }
 
+    qemuSecurityReleaseLabel(driver->securityManager, vm->def);
+
     /* clear all private data entries which are no longer needed */
     qemuDomainObjPrivateDataClear(priv);