lxc: Check ACLs before parsing the whole domain XML

Utilise the new virDomainDefIDsParseString() for that.

Fixes: CVE-2025-12748
Reported-by: Святослав Терешин <s.tereshin@fobos-nt.ru>
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
index 80cf07d2e5ffca168c6cc16a7b3f5b7925ffbf61..c0a93c0444bb48075075289149f3f00118c0ef25 100644 (file)
--- a/src/lxc/lxc_driver.c
+++ b/src/lxc/lxc_driver.c
@@ -409,6 +409,15 @@ lxcDomainDefineXMLFlags(virConnectPtr conn, const char *xml, unsigned int flags)
     if (!(caps = virLXCDriverGetCapabilities(driver, false)))
         goto cleanup;
 
+    /* Avoid parsing the whole domain definition for ACL checks */
+    if (!(def = virDomainDefIDsParseString(xml, driver->xmlopt, parse_flags)))
+        goto cleanup;
+
+    if (virDomainDefineXMLFlagsEnsureACL(conn, def) < 0)
+        goto cleanup;
+
+    g_clear_pointer(&def, virDomainDefFree);
+
     if (!(def = virDomainDefParseString(xml, driver->xmlopt,
                                         NULL, parse_flags)))
         goto cleanup;
@@ -416,9 +425,6 @@ lxcDomainDefineXMLFlags(virConnectPtr conn, const char *xml, unsigned int flags)
     if (virXMLCheckIllegalChars("name", def->name, "\n") < 0)
         goto cleanup;
 
-    if (virDomainDefineXMLFlagsEnsureACL(conn, def) < 0)
-        goto cleanup;
-
     if (virSecurityManagerVerify(driver->securityManager, def) < 0)
         goto cleanup;
 
@@ -1066,13 +1072,19 @@ lxcDomainCreateXMLWithFiles(virConnectPtr conn,
     if (!(caps = virLXCDriverGetCapabilities(driver, false)))
         goto cleanup;
 
-    if (!(def = virDomainDefParseString(xml, driver->xmlopt,
-                                        NULL, parse_flags)))
+    /* Avoid parsing the whole domain definition for ACL checks */
+    if (!(def = virDomainDefIDsParseString(xml, driver->xmlopt, parse_flags)))
         goto cleanup;
 
     if (virDomainCreateXMLWithFilesEnsureACL(conn, def) < 0)
         goto cleanup;
 
+    g_clear_pointer(&def, virDomainDefFree);
+
+    if (!(def = virDomainDefParseString(xml, driver->xmlopt,
+                                        NULL, parse_flags)))
+        goto cleanup;
+
     if (virSecurityManagerVerify(driver->securityManager, def) < 0)
         goto cleanup;