diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index cf857bbe15afaac4ce5602d95698e8e8c5258caf..2533ec84d1850021d4f21414a1b416b0a7c789ab 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -10575,10 +10575,10 @@ qemuNodeDeviceDetachFlags(virNodeDevicePtr dev,
                           unsigned int flags)
 {
     virQEMUDriverPtr driver = dev->conn->privateData;
-    virPCIDevicePtr pci;
+    virPCIDevicePtr pci = NULL;
     unsigned domain, bus, slot, function;
     int ret = -1;
-    bool in_inactive_list = false;
+    bool in_inactive_list = true;
     virNodeDeviceDefPtr def = NULL;
     char *xml = NULL;
 
@@ -10603,13 +10603,15 @@ qemuNodeDeviceDetachFlags(virNodeDevicePtr dev,
         goto cleanup;
 
     if (!driverName || STREQ(driverName, "kvm")) {
-        virPCIDeviceSetStubDriver(pci, "pci-stub");
+        if (virPCIDeviceSetStubDriver(pci, "pci-stub") < 0)
+            goto cleanup;
     } else if (STREQ(driverName, "vfio")) {
-        virPCIDeviceSetStubDriver(pci, "vfio-pci");
+        if (virPCIDeviceSetStubDriver(pci, "vfio-pci") < 0)
+            goto cleanup;
     } else {
         virReportError(VIR_ERR_INVALID_ARG,
                        _("unknown driver name '%s'"), driverName);
-        goto out;
+        goto cleanup;
     }
 
     virObjectLock(driver->activePciHostdevs);
@@ -10624,9 +10626,9 @@ qemuNodeDeviceDetachFlags(virNodeDevicePtr dev,
 out:
     virObjectUnlock(driver->inactivePciHostdevs);
     virObjectUnlock(driver->activePciHostdevs);
+cleanup:
     if (in_inactive_list)
         virPCIDeviceFree(pci);
-cleanup:
     virNodeDeviceDefFree(def);
     VIR_FREE(xml);
     return ret;
diff --git a/src/qemu/qemu_hostdev.c b/src/qemu/qemu_hostdev.c
index 9013f60afba4ebb2612ebb32c28c533475970a35..7a9e6eba05c46a3af34da8d22c001827e6f25851 100644
--- a/src/qemu/qemu_hostdev.c
+++ b/src/qemu/qemu_hostdev.c
@@ -70,9 +70,15 @@ qemuGetPciHostDeviceList(virDomainHostdevDefPtr *hostdevs, int nhostdevs)
         virPCIDeviceSetManaged(dev, hostdev->managed);
         if (hostdev->source.subsys.u.pci.backend
             == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO) {
-            virPCIDeviceSetStubDriver(dev, "vfio-pci");
+            if (virPCIDeviceSetStubDriver(dev, "vfio-pci") < 0) {
+                virObjectUnref(list);
+                return NULL;
+            }
         } else {
-            virPCIDeviceSetStubDriver(dev, "pci-stub");
+            if (virPCIDeviceSetStubDriver(dev, "pci-stub") < 0) {
+                virObjectUnref(list);
+                return NULL;
+            }
         }
     }
 
@@ -130,6 +136,7 @@ int qemuUpdateActivePciHostdevs(virQEMUDriverPtr driver,
                                 virDomainDefPtr def)
 {
     virDomainHostdevDefPtr hostdev = NULL;
+    virPCIDevicePtr dev = NULL;
     int i;
     int ret = -1;
 
@@ -140,7 +147,6 @@ int qemuUpdateActivePciHostdevs(virQEMUDriverPtr driver,
     virObjectLock(driver->inactivePciHostdevs);
 
     for (i = 0; i < def->nhostdevs; i++) {
-        virPCIDevicePtr dev = NULL;
         hostdev = def->hostdevs[i];
 
         if (hostdev->mode != VIR_DOMAIN_HOSTDEV_MODE_SUBSYS)
@@ -159,9 +165,12 @@ int qemuUpdateActivePciHostdevs(virQEMUDriverPtr driver,
         virPCIDeviceSetManaged(dev, hostdev->managed);
         if (hostdev->source.subsys.u.pci.backend
             == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO) {
-            virPCIDeviceSetStubDriver(dev, "vfio-pci");
+            if (virPCIDeviceSetStubDriver(dev, "vfio-pci") < 0)
+                goto cleanup;
         } else {
-            virPCIDeviceSetStubDriver(dev, "pci-stub");
+            if (virPCIDeviceSetStubDriver(dev, "pci-stub") < 0)
+                goto cleanup;
+
         }
         virPCIDeviceSetUsedBy(dev, def->name);
 
@@ -170,14 +179,14 @@ int qemuUpdateActivePciHostdevs(virQEMUDriverPtr driver,
         virPCIDeviceSetRemoveSlot(dev, hostdev->origstates.states.pci.remove_slot);
         virPCIDeviceSetReprobe(dev, hostdev->origstates.states.pci.reprobe);
 
-        if (virPCIDeviceListAdd(driver->activePciHostdevs, dev) < 0) {
-            virPCIDeviceFree(dev);
+        if (virPCIDeviceListAdd(driver->activePciHostdevs, dev) < 0)
             goto cleanup;
-        }
+        dev = NULL;
     }
 
     ret = 0;
 cleanup:
+    virPCIDeviceFree(dev);
     virObjectUnlock(driver->activePciHostdevs);
     virObjectUnlock(driver->inactivePciHostdevs);
     return ret;
diff --git a/src/util/virpci.c b/src/util/virpci.c
index 89c1eea4cb75c5fc7c9f2afbaaf37966a0d11c9b..d00c3ee8222ae41cf60c277a6810d3febf4b9366 100644
--- a/src/util/virpci.c
+++ b/src/util/virpci.c
@@ -69,7 +69,7 @@ struct _virPCIDevice {
     bool          has_flr;
     bool          has_pm_reset;
     bool          managed;
-    const char   *stubDriver;
+    char          *stubDriver;
 
     /* used by reattach function */
     bool          unbind_from_stub;
@@ -1480,6 +1480,7 @@ virPCIDeviceFree(virPCIDevicePtr dev)
         return;
     VIR_DEBUG("%s %s: freeing", dev->id, dev->name);
     VIR_FREE(dev->path);
+    VIR_FREE(dev->stubDriver);
     VIR_FREE(dev);
 }
 
@@ -1500,10 +1501,11 @@ virPCIDeviceGetManaged(virPCIDevicePtr dev)
     return dev->managed;
 }
 
-void
+int
 virPCIDeviceSetStubDriver(virPCIDevicePtr dev, const char *driver)
 {
-    dev->stubDriver = driver;
+    VIR_FREE(dev->stubDriver);
+    return driver ? VIR_STRDUP(dev->stubDriver, driver) : 0;
 }
 
 const char *
diff --git a/src/util/virpci.h b/src/util/virpci.h
index 7bcadb42f6d5604d7a827c6308ac2c086002551b..17b15fef06482dab2ade1f267c7907b772b08e62 100644
--- a/src/util/virpci.h
+++ b/src/util/virpci.h
@@ -62,8 +62,8 @@ int virPCIDeviceReset(virPCIDevicePtr dev,
 void virPCIDeviceSetManaged(virPCIDevice *dev,
                             bool managed);
 unsigned int virPCIDeviceGetManaged(virPCIDevice *dev);
-void virPCIDeviceSetStubDriver(virPCIDevicePtr dev,
-                               const char *driver);
+int virPCIDeviceSetStubDriver(virPCIDevicePtr dev,
+                              const char *driver);
 const char *virPCIDeviceGetStubDriver(virPCIDevicePtr dev);
 void virPCIDeviceSetUsedBy(virPCIDevice *dev,
                            const char *used_by);
diff --git a/src/xen/xen_driver.c b/src/xen/xen_driver.c
index bf283a76c1eeebfe5c49df023d74ba893f6eb764..ffc6e414eb1301e2a8def7fc9cc9881b701e8c83 100644
--- a/src/xen/xen_driver.c
+++ b/src/xen/xen_driver.c
@@ -2432,7 +2432,8 @@ xenUnifiedNodeDeviceDetachFlags(virNodeDevicePtr dev,
         return -1;
 
     if (!driverName) {
-        virPCIDeviceSetStubDriver(pci, "pciback");
+        if (virPCIDeviceSetStubDriver(pci, "pciback") < 0)
+            goto out;
     } else {
         virReportError(VIR_ERR_INVALID_ARG,
                        _("unknown driver name '%s'"), driverName);