net: do not try to load protocol module via itself

Otherwise we get infinite recursion.

Closes: 45729

diff --git a/grub-core/net/net.c b/grub-core/net/net.c
index 21a4e94d11f8c8322b44f56ab60ad5efe8d13271..a0472d5d464a1807093c9b95487a2e5ba5a8ad28 100644 (file)
--- a/grub-core/net/net.c
+++ b/grub-core/net/net.c
@@ -1341,6 +1341,43 @@ grub_net_open_real (const char *name)
       }
       if (try == 0)
        {
+         const char *prefix, *root;
+         char *prefdev, *comma;
+         int skip = 0;
+         grub_size_t devlen;
+
+         /* Do not attempt to load module if it requires protocol provided
+            by this module - it results in infinite recursion. Just continue,
+            fail and cleanup on next iteration.
+          */
+         prefix = grub_env_get ("prefix");
+         if (!prefix)
+           continue;
+
+         prefdev = grub_file_get_device_name (prefix);
+         if (!prefdev)
+           {
+             root = grub_env_get ("root");
+             if (!root)
+               continue;
+             prefdev = grub_strdup (root);
+             if (!prefdev)
+               continue;
+           }
+
+         comma = grub_strchr (prefdev, ',');
+         if (comma)
+           *comma = '\0';
+         devlen = grub_strlen (prefdev);
+
+         if (protnamelen == devlen && grub_memcmp (prefdev, protname, devlen) == 0)
+           skip = 1;
+
+         grub_free (prefdev);
+
+         if (skip)
+           continue;
+
          if (sizeof ("http") - 1 == protnamelen
              && grub_memcmp ("http", protname, protnamelen) == 0)
            {