api: disallow virConnectGetDomainCapabilities on read-only connections

This API can be used to execute arbitrary emulators.
Forbid it on read-only connections.

Fixes: CVE-2019-10167
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
(cherry picked from commit 8afa68bac0)
Signed-off-by: Ján Tomko <jtomko@redhat.com>

src/libvirt-domain.c

@@ -1077,9 +1077,7 @@ virDomainRestoreFlags(virConnectPtr conn, const char *from, const char *dxml,
  * previously by virDomainSave() or virDomainSaveFlags().
  *
  * No security-sensitive data will be included unless @flags contains
- * VIR_DOMAIN_XML_SECURE; this flag is rejected on read-only
- * connections.  For this API, @flags should not contain either
- * VIR_DOMAIN_XML_INACTIVE or VIR_DOMAIN_XML_UPDATE_CPU.
+ * VIR_DOMAIN_XML_SECURE.
  *
  * Returns a 0 terminated UTF-8 encoded XML instance, or NULL in case of
  * error.  The caller must free() the returned value.
@@ -1095,12 +1093,7 @@ virDomainSaveImageGetXMLDesc(virConnectPtr conn, const char *file,
 
     virCheckConnectReturn(conn, NULL);
     virCheckNonNullArgGoto(file, error);
-
-    if ((conn->flags & VIR_CONNECT_RO) && (flags & VIR_DOMAIN_XML_SECURE)) {
-        virReportError(VIR_ERR_OPERATION_DENIED, "%s",
-                       _("virDomainSaveImageGetXMLDesc with secure flag"));
-        goto error;
-    }
+    virCheckReadOnlyGoto(conn->flags, error);
 
     if (conn->driver->domainSaveImageGetXMLDesc) {
         char *ret;
@@ -11125,6 +11118,7 @@ virConnectGetDomainCapabilities(virConnectPtr conn,
     virResetLastError();
 
     virCheckConnectReturn(conn, NULL);
+    virCheckReadOnlyGoto(conn->flags, error);
 
     if (conn->driver->connectGetDomainCapabilities) {
         char *ret;

src/qemu/qemu_driver.c

@@ -6866,7 +6866,7 @@ qemuDomainSaveImageGetXMLDesc(virConnectPtr conn, const char *path,
     if (fd < 0)
         goto cleanup;
 
-    if (virDomainSaveImageGetXMLDescEnsureACL(conn, def, flags) < 0)
+    if (virDomainSaveImageGetXMLDescEnsureACL(conn, def) < 0)
         goto cleanup;
 
     ret = qemuDomainDefFormatXML(driver, def, flags);

src/qemu/qemu_hotplug.c

@@ -4041,6 +4041,7 @@ qemuDomainChangeGraphicsPasswords(virQEMUDriverPtr driver,
     time_t now = time(NULL);
     char expire_time [64];
     const char *connected = NULL;
+    const char *password;
     int ret = -1;
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
 
@@ -4048,16 +4049,14 @@ qemuDomainChangeGraphicsPasswords(virQEMUDriverPtr driver,
         ret = 0;
         goto cleanup;
     }
+    password = auth->passwd ? auth->passwd : defaultPasswd;
 
     if (auth->connected)
         connected = virDomainGraphicsAuthConnectedTypeToString(auth->connected);
 
     if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
         goto cleanup;
-    ret = qemuMonitorSetPassword(priv->mon,
-                                 type,
-                                 auth->passwd ? auth->passwd : defaultPasswd,
-                                 connected);
+    ret = qemuMonitorSetPassword(priv->mon, type, password, connected);
 
     if (ret == -2) {
         if (type != VIR_DOMAIN_GRAPHICS_TYPE_VNC) {
@@ -4065,14 +4064,15 @@ qemuDomainChangeGraphicsPasswords(virQEMUDriverPtr driver,
                            _("Graphics password only supported for VNC"));
             ret = -1;
         } else {
-            ret = qemuMonitorSetVNCPassword(priv->mon,
-                                            auth->passwd ? auth->passwd : defaultPasswd);
+            ret = qemuMonitorSetVNCPassword(priv->mon, password);
         }
     }
     if (ret != 0)
         goto end_job;
 
-    if (auth->expires) {
+    if (password[0] == '\0') {
+        snprintf(expire_time, sizeof(expire_time), "now");
+    } else if (auth->expires) {
         time_t lifetime = auth->validTo - now;
         if (lifetime <= 0)
             snprintf(expire_time, sizeof(expire_time), "now");

src/remote/remote_protocol.x

@@ -4907,8 +4907,7 @@ enum remote_procedure {
     /**
      * @generate: both
      * @priority: high
-     * @acl: domain:read
-     * @acl: domain:read_secure:VIR_DOMAIN_XML_SECURE
+     * @acl: domain:write
      */
     REMOTE_PROC_DOMAIN_SAVE_IMAGE_GET_XML_DESC = 235,
 

src/storage/storage_backend_fs.c

@@ -1,7 +1,7 @@
 /*
  * storage_backend_fs.c: storage backend for FS and directory handling
  *
- * Copyright (C) 2007-2014 Red Hat, Inc.
+ * Copyright (C) 2007-2015 Red Hat, Inc.
  * Copyright (C) 2007-2008 Daniel P. Berrange
  *
  * This library is free software; you can redistribute it and/or
@@ -1057,6 +1057,14 @@ virStorageBackendFileSystemVolCreate(virConnectPtr conn ATTRIBUTE_UNUSED,
     else
         vol->type = VIR_STORAGE_VOL_FILE;
 
+    /* Volumes within a directory pools are not recursive; do not
+     * allow escape to ../ or a subdir */
+    if (strchr(vol->name, '/')) {
+        virReportError(VIR_ERR_OPERATION_INVALID,
+                       _("volume name '%s' cannot contain '/'"), vol->name);
+        return -1;
+    }
+
     VIR_FREE(vol->target.path);
     if (virAsprintf(&vol->target.path, "%s/%s",
                     pool->def->target.path,