security_selinux: Take @privileged into account

https://bugzilla.redhat.com/show_bug.cgi?id=1124841

If running in session mode it may happen that we fail to set
correct SELinux label, but the image may still be readable to
the qemu process. Take this into account.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
(cherry picked from commit 00e5b967)

src/security/security_selinux.c

@@ -886,7 +886,8 @@ virSecuritySELinuxGetSecurityProcessLabel(virSecurityManagerPtr mgr ATTRIBUTE_UN
  * return 1 if labelling was not possible.  Otherwise, require a label
  * change, and return 0 for success, -1 for failure.  */
 static int
-virSecuritySELinuxSetFileconHelper(const char *path, char *tcon, bool optional)
+virSecuritySELinuxSetFileconHelper(const char *path, char *tcon,
+                                   bool optional, bool privileged)
 {
     security_context_t econ;
 
@@ -915,7 +916,10 @@ virSecuritySELinuxSetFileconHelper(const char *path, char *tcon, bool optional)
             virReportSystemError(setfilecon_errno,
                                  _("unable to set security context '%s' on '%s'"),
                                  tcon, path);
-            if (security_getenforce() == 1)
+            /* However, don't claim error if SELinux is in Enforcing mode and
+             * we are running as unprivileged user and we really did see EPERM.
+             * Otherwise we want to return error if SELinux is Enforcing. */
+            if (security_getenforce() == 1 && (setfilecon_errno != EPERM || privileged))
                 return -1;
         } else {
             const char *msg;
@@ -939,15 +943,19 @@ virSecuritySELinuxSetFileconHelper(const char *path, char *tcon, bool optional)
 }
 
 static int
-virSecuritySELinuxSetFileconOptional(const char *path, char *tcon)
+virSecuritySELinuxSetFileconOptional(virSecurityManagerPtr mgr,
+                                     const char *path, char *tcon)
 {
-    return virSecuritySELinuxSetFileconHelper(path, tcon, true);
+    bool privileged = virSecurityManagerGetPrivileged(mgr);
+    return virSecuritySELinuxSetFileconHelper(path, tcon, true, privileged);
 }
 
 static int
-virSecuritySELinuxSetFilecon(const char *path, char *tcon)
+virSecuritySELinuxSetFilecon(virSecurityManagerPtr mgr,
+                             const char *path, char *tcon)
 {
-    return virSecuritySELinuxSetFileconHelper(path, tcon, false);
+    bool privileged = virSecurityManagerGetPrivileged(mgr);
+    return virSecuritySELinuxSetFileconHelper(path, tcon, false, privileged);
 }
 
 static int
@@ -1037,7 +1045,7 @@ virSecuritySELinuxRestoreSecurityFileLabel(virSecurityManagerPtr mgr,
         VIR_WARN("cannot lookup default selinux label for %s", newpath);
         rc = 0;
     } else {
-        rc = virSecuritySELinuxSetFilecon(newpath, fcon);
+        rc = virSecuritySELinuxSetFilecon(mgr, newpath, fcon);
     }
 
  err:
@@ -1064,12 +1072,13 @@ virSecuritySELinuxSetSecurityTPMFileLabel(virSecurityManagerPtr mgr,
     switch (tpm->type) {
     case VIR_DOMAIN_TPM_TYPE_PASSTHROUGH:
         tpmdev = tpm->data.passthrough.source.data.file.path;
-        rc = virSecuritySELinuxSetFilecon(tpmdev, seclabel->imagelabel);
+        rc = virSecuritySELinuxSetFilecon(mgr, tpmdev, seclabel->imagelabel);
         if (rc < 0)
             return -1;
 
         if ((cancel_path = virTPMCreateCancelPath(tpmdev)) != NULL) {
-            rc = virSecuritySELinuxSetFilecon(cancel_path,
+            rc = virSecuritySELinuxSetFilecon(mgr,
+                                              cancel_path,
                                               seclabel->imagelabel);
             VIR_FREE(cancel_path);
             if (rc < 0) {
@@ -1223,22 +1232,26 @@ virSecuritySELinuxSetSecurityImageLabelInternal(virSecurityManagerPtr mgr,
         return 0;
 
     if (disk_seclabel && disk_seclabel->relabel && disk_seclabel->label) {
-        ret = virSecuritySELinuxSetFilecon(src->path, disk_seclabel->label);
+        ret = virSecuritySELinuxSetFilecon(mgr, src->path, disk_seclabel->label);
     } else if (first) {
         if (src->shared) {
-            ret = virSecuritySELinuxSetFileconOptional(src->path,
+            ret = virSecuritySELinuxSetFileconOptional(mgr,
+                                                       src->path,
                                                        data->file_context);
         } else if (src->readonly) {
-            ret = virSecuritySELinuxSetFileconOptional(src->path,
+            ret = virSecuritySELinuxSetFileconOptional(mgr,
+                                                       src->path,
                                                        data->content_context);
         } else if (secdef->imagelabel) {
-            ret = virSecuritySELinuxSetFileconOptional(src->path,
+            ret = virSecuritySELinuxSetFileconOptional(mgr,
+                                                       src->path,
                                                        secdef->imagelabel);
         } else {
             ret = 0;
         }
     } else {
-        ret = virSecuritySELinuxSetFileconOptional(src->path,
+        ret = virSecuritySELinuxSetFileconOptional(mgr,
+                                                   src->path,
                                                    data->content_context);
     }
 
@@ -1290,17 +1303,18 @@ virSecuritySELinuxSetSecurityDiskLabel(virSecurityManagerPtr mgr,
     return 0;
 }
 
-
 static int
 virSecuritySELinuxSetSecurityHostdevLabelHelper(const char *file, void *opaque)
 {
     virSecurityLabelDefPtr secdef;
-    virDomainDefPtr def = opaque;
+    virSecuritySELinuxCallbackDataPtr data = opaque;
+    virSecurityManagerPtr mgr = data->mgr;
+    virDomainDefPtr def = data->def;
 
     secdef = virDomainDefGetSecurityLabelDef(def, SECURITY_SELINUX_NAME);
     if (secdef == NULL)
         return 0;
-    return virSecuritySELinuxSetFilecon(file, secdef->imagelabel);
+    return virSecuritySELinuxSetFilecon(mgr, file, secdef->imagelabel);
 }
 
 static int
@@ -1331,13 +1345,14 @@ virSecuritySELinuxSetSecuritySCSILabel(virSCSIDevicePtr dev,
         return 0;
 
     if (virSCSIDeviceGetShareable(dev))
-        return virSecuritySELinuxSetFileconOptional(file,
+        return virSecuritySELinuxSetFileconOptional(mgr, file,
                                                     data->file_context);
     else if (virSCSIDeviceGetReadonly(dev))
-        return virSecuritySELinuxSetFileconOptional(file,
+        return virSecuritySELinuxSetFileconOptional(mgr, file,
                                                     data->content_context);
     else
-        return virSecuritySELinuxSetFileconOptional(file, secdef->imagelabel);
+        return virSecuritySELinuxSetFileconOptional(mgr, file,
+                                                    secdef->imagelabel);
 }
 
 static int
@@ -1350,6 +1365,8 @@ virSecuritySELinuxSetSecurityHostdevSubsysLabel(virSecurityManagerPtr mgr,
     virDomainHostdevSubsysUSBPtr usbsrc = &dev->source.subsys.u.usb;
     virDomainHostdevSubsysPCIPtr pcisrc = &dev->source.subsys.u.pci;
     virDomainHostdevSubsysSCSIPtr scsisrc = &dev->source.subsys.u.scsi;
+    virSecuritySELinuxCallbackData data = {.mgr = mgr, .def = def};
+
     int ret = -1;
 
     /* Like virSecuritySELinuxSetSecurityImageLabelInternal() for a networked
@@ -1372,7 +1389,7 @@ virSecuritySELinuxSetSecurityHostdevSubsysLabel(virSecurityManagerPtr mgr,
         if (!usb)
             goto done;
 
-        ret = virUSBDeviceFileIterate(usb, virSecuritySELinuxSetSecurityUSBLabel, def);
+        ret = virUSBDeviceFileIterate(usb, virSecuritySELinuxSetSecurityUSBLabel, &data);
         virUSBDeviceFree(usb);
         break;
     }
@@ -1392,10 +1409,10 @@ virSecuritySELinuxSetSecurityHostdevSubsysLabel(virSecurityManagerPtr mgr,
                 virPCIDeviceFree(pci);
                 goto done;
             }
-            ret = virSecuritySELinuxSetSecurityPCILabel(pci, vfioGroupDev, def);
+            ret = virSecuritySELinuxSetSecurityPCILabel(pci, vfioGroupDev, &data);
             VIR_FREE(vfioGroupDev);
         } else {
-            ret = virPCIDeviceFileIterate(pci, virSecuritySELinuxSetSecurityPCILabel, def);
+            ret = virPCIDeviceFileIterate(pci, virSecuritySELinuxSetSecurityPCILabel, &data);
         }
         virPCIDeviceFree(pci);
         break;
@@ -1403,7 +1420,6 @@ virSecuritySELinuxSetSecurityHostdevSubsysLabel(virSecurityManagerPtr mgr,
 
     case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI: {
         virDomainHostdevSubsysSCSIHostPtr scsihostsrc = &scsisrc->u.host;
-        virSecuritySELinuxCallbackData data = {.mgr = mgr, .def = def};
 
         virSCSIDevicePtr scsi =
             virSCSIDeviceNew(NULL,
@@ -1433,7 +1449,8 @@ virSecuritySELinuxSetSecurityHostdevSubsysLabel(virSecurityManagerPtr mgr,
 
 
 static int
-virSecuritySELinuxSetSecurityHostdevCapsLabel(virDomainDefPtr def,
+virSecuritySELinuxSetSecurityHostdevCapsLabel(virSecurityManagerPtr mgr,
+                                              virDomainDefPtr def,
                                               virDomainHostdevDefPtr dev,
                                               const char *vroot)
 {
@@ -1455,7 +1472,7 @@ virSecuritySELinuxSetSecurityHostdevCapsLabel(virDomainDefPtr def,
             if (VIR_STRDUP(path, dev->source.caps.u.storage.block) < 0)
                 return -1;
         }
-        ret = virSecuritySELinuxSetFilecon(path, secdef->imagelabel);
+        ret = virSecuritySELinuxSetFilecon(mgr, path, secdef->imagelabel);
         VIR_FREE(path);
         break;
     }
@@ -1469,7 +1486,7 @@ virSecuritySELinuxSetSecurityHostdevCapsLabel(virDomainDefPtr def,
             if (VIR_STRDUP(path, dev->source.caps.u.misc.chardev) < 0)
                 return -1;
         }
-        ret = virSecuritySELinuxSetFilecon(path, secdef->imagelabel);
+        ret = virSecuritySELinuxSetFilecon(mgr, path, secdef->imagelabel);
         VIR_FREE(path);
         break;
     }
@@ -1502,7 +1519,8 @@ virSecuritySELinuxSetSecurityHostdevLabel(virSecurityManagerPtr mgr,
                                                                dev, vroot);
 
     case VIR_DOMAIN_HOSTDEV_MODE_CAPABILITIES:
-        return virSecuritySELinuxSetSecurityHostdevCapsLabel(def, dev, vroot);
+        return virSecuritySELinuxSetSecurityHostdevCapsLabel(mgr, def,
+                                                             dev, vroot);
 
     default:
         return 0;
@@ -1707,7 +1725,8 @@ virSecuritySELinuxRestoreSecurityHostdevLabel(virSecurityManagerPtr mgr,
 
 
 static int
-virSecuritySELinuxSetSecurityChardevLabel(virDomainDefPtr def,
+virSecuritySELinuxSetSecurityChardevLabel(virSecurityManagerPtr mgr,
+                                          virDomainDefPtr def,
                                           virDomainChrDefPtr dev,
                                           virDomainChrSourceDefPtr dev_source)
 
@@ -1737,13 +1756,15 @@ virSecuritySELinuxSetSecurityChardevLabel(virDomainDefPtr def,
     switch (dev_source->type) {
     case VIR_DOMAIN_CHR_TYPE_DEV:
     case VIR_DOMAIN_CHR_TYPE_FILE:
-        ret = virSecuritySELinuxSetFilecon(dev_source->data.file.path,
+        ret = virSecuritySELinuxSetFilecon(mgr,
+                                           dev_source->data.file.path,
                                            imagelabel);
         break;
 
     case VIR_DOMAIN_CHR_TYPE_UNIX:
         if (!dev_source->data.nix.listen) {
-            if (virSecuritySELinuxSetFilecon(dev_source->data.nix.path,
+            if (virSecuritySELinuxSetFilecon(mgr,
+                                             dev_source->data.nix.path,
                                              imagelabel) < 0)
                 goto done;
         }
@@ -1755,11 +1776,12 @@ virSecuritySELinuxSetSecurityChardevLabel(virDomainDefPtr def,
             (virAsprintf(&out, "%s.out", dev_source->data.file.path) < 0))
             goto done;
         if (virFileExists(in) && virFileExists(out)) {
-            if ((virSecuritySELinuxSetFilecon(in, imagelabel) < 0) ||
-                (virSecuritySELinuxSetFilecon(out, imagelabel) < 0)) {
+            if ((virSecuritySELinuxSetFilecon(mgr, in, imagelabel) < 0) ||
+                (virSecuritySELinuxSetFilecon(mgr, out, imagelabel) < 0)) {
                 goto done;
             }
-        } else if (virSecuritySELinuxSetFilecon(dev_source->data.file.path,
+        } else if (virSecuritySELinuxSetFilecon(mgr,
+                                                dev_source->data.file.path,
                                                 imagelabel) < 0) {
             goto done;
         }
@@ -2000,7 +2022,7 @@ virSecuritySELinuxReleaseSecurityLabel(virSecurityManagerPtr mgr,
 
 
 static int
-virSecuritySELinuxSetSavedStateLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
+virSecuritySELinuxSetSavedStateLabel(virSecurityManagerPtr mgr,
                                      virDomainDefPtr def,
                                      const char *savefile)
 {
@@ -2010,7 +2032,7 @@ virSecuritySELinuxSetSavedStateLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
     if (!secdef || !secdef->relabel)
         return 0;
 
-    return virSecuritySELinuxSetFilecon(savefile, secdef->imagelabel);
+    return virSecuritySELinuxSetFilecon(mgr, savefile, secdef->imagelabel);
 }
 
 
@@ -2242,14 +2264,16 @@ virSecuritySELinuxClearSecuritySocketLabel(virSecurityManagerPtr mgr ATTRIBUTE_U
 static int
 virSecuritySELinuxSetSecurityChardevCallback(virDomainDefPtr def,
                                              virDomainChrDefPtr dev,
-                                             void *opaque ATTRIBUTE_UNUSED)
+                                             void *opaque)
 {
+    virSecurityManagerPtr mgr = opaque;
+
     /* This is taken care of by processing of def->serials */
     if (dev->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_CONSOLE &&
         dev->targetType == VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_SERIAL)
         return 0;
 
-    return virSecuritySELinuxSetSecurityChardevLabel(def, dev, &dev->source);
+    return virSecuritySELinuxSetSecurityChardevLabel(mgr, def, dev, &dev->source);
 }
 
 
@@ -2270,10 +2294,11 @@ virSecuritySELinuxSetSecuritySmartcardCallback(virDomainDefPtr def,
         database = dev->data.cert.database;
         if (!database)
             database = VIR_DOMAIN_SMARTCARD_DEFAULT_DATABASE;
-        return virSecuritySELinuxSetFilecon(database, data->content_context);
+        return virSecuritySELinuxSetFilecon(mgr, database, data->content_context);
 
     case VIR_DOMAIN_SMARTCARD_TYPE_PASSTHROUGH:
-        return virSecuritySELinuxSetSecurityChardevLabel(def, NULL, &dev->data.passthru);
+        return virSecuritySELinuxSetSecurityChardevLabel(mgr, def, NULL,
+                                                         &dev->data.passthru);
 
     default:
         virReportError(VIR_ERR_INTERNAL_ERROR,
@@ -2330,7 +2355,7 @@ virSecuritySELinuxSetSecurityAllLabel(virSecurityManagerPtr mgr,
     if (virDomainChrDefForeach(def,
                                true,
                                virSecuritySELinuxSetSecurityChardevCallback,
-                               NULL) < 0)
+                               mgr) < 0)
         return -1;
 
     if (virDomainSmartcardDefForeach(def,
@@ -2343,23 +2368,28 @@ virSecuritySELinuxSetSecurityAllLabel(virSecurityManagerPtr mgr,
      * is really a disk, qemu can read and write to it. */
     if (def->os.loader && def->os.loader->nvram &&
         secdef && secdef->imagelabel &&
-        virSecuritySELinuxSetFilecon(def->os.loader->nvram, secdef->imagelabel) < 0)
+        virSecuritySELinuxSetFilecon(mgr, def->os.loader->nvram,
+                                     secdef->imagelabel) < 0)
         return -1;
 
     if (def->os.kernel &&
-        virSecuritySELinuxSetFilecon(def->os.kernel, data->content_context) < 0)
+        virSecuritySELinuxSetFilecon(mgr, def->os.kernel,
+                                     data->content_context) < 0)
         return -1;
 
     if (def->os.initrd &&
-        virSecuritySELinuxSetFilecon(def->os.initrd, data->content_context) < 0)
+        virSecuritySELinuxSetFilecon(mgr, def->os.initrd,
+                                     data->content_context) < 0)
         return -1;
 
     if (def->os.dtb &&
-        virSecuritySELinuxSetFilecon(def->os.dtb, data->content_context) < 0)
+        virSecuritySELinuxSetFilecon(mgr, def->os.dtb,
+                                     data->content_context) < 0)
         return -1;
 
     if (stdin_path &&
-        virSecuritySELinuxSetFilecon(stdin_path, data->content_context) < 0)
+        virSecuritySELinuxSetFilecon(mgr, stdin_path,
+                                     data->content_context) < 0)
         return -1;
 
     return 0;
@@ -2507,7 +2537,7 @@ virSecuritySELinuxGetSecurityMountOptions(virSecurityManagerPtr mgr,
 }
 
 static int
-virSecuritySELinuxDomainSetDirLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
+virSecuritySELinuxDomainSetDirLabel(virSecurityManagerPtr mgr,
                                     virDomainDefPtr def,
                                     const char *path)
 {
@@ -2517,7 +2547,7 @@ virSecuritySELinuxDomainSetDirLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
     if (!seclabel || !seclabel->relabel)
         return 0;
 
-    return virSecuritySELinuxSetFilecon(path, seclabel->imagelabel);
+    return virSecuritySELinuxSetFilecon(mgr, path, seclabel->imagelabel);
 }
 
 virSecurityDriver virSecurityDriverSELinux = {