File 0004-efi-chainloader-fix-missing-file_path-in-loaded_imag.patch of Package grub2

From 23843a18420aadb069f9f2b217a3262b491b4f91 Mon Sep 17 00:00:00 2001
From: Michael Chang <mchang@suse.com>
Date: Wed, 30 Apr 2025 21:16:50 +0800
Subject: [PATCH 4/4] efi/chainloader: fix missing file_path in loaded_image

The file_path field in the loaded_image protocol may be unset for
chainloaded target images. When this occurs, populate the file_path to
ensure the target image can use the loaded_image protocol for location
dependent operations, such as reading configuration files from its
directory. Without this, the chainloaded image may fail to start due to
an inability to reconfigure itself properly.

Signed-off-by: Michael Chang <mchang@suse.com>
---
 grub-core/loader/efi/chainloader.c | 52 +++++++++++++++++-------------
 1 file changed, 29 insertions(+), 23 deletions(-)

diff --git a/grub-core/loader/efi/chainloader.c b/grub-core/loader/efi/chainloader.c
index 7e2847217f..9b70e1e61d 100644
--- a/grub-core/loader/efi/chainloader.c
+++ b/grub-core/loader/efi/chainloader.c
@@ -222,6 +222,29 @@ make_file_path (grub_efi_device_path_t *dp, const char *filename)
   return file_path;
 }
 
+static grub_efi_device_path_t *
+grub_efi_get_media_file_path (grub_efi_device_path_t *dp)
+{
+  while (1)
+    {
+      grub_efi_uint8_t type;
+      grub_efi_uint8_t subtype;
+
+      if (GRUB_EFI_END_ENTIRE_DEVICE_PATH (dp))
+        break;
+
+      type = GRUB_EFI_DEVICE_PATH_TYPE (dp);
+      subtype = GRUB_EFI_DEVICE_PATH_SUBTYPE (dp);
+
+      if (type == GRUB_EFI_MEDIA_DEVICE_PATH_TYPE && subtype == GRUB_EFI_FILE_PATH_DEVICE_PATH_SUBTYPE)
+	return dp;
+
+      dp = GRUB_EFI_NEXT_DEVICE_PATH (dp);
+    }
+
+  return NULL;
+}
+
 #ifdef SUPPORT_SECURE_BOOT
 #define SHIM_LOCK_GUID \
   { 0x605dab50, 0xe046, 0x4300, {0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23} }
@@ -461,29 +484,6 @@ relocate_coff (pe_coff_loader_image_context_t *context, void *data)
   return GRUB_EFI_SUCCESS;
 }
 
-static grub_efi_device_path_t *
-grub_efi_get_media_file_path (grub_efi_device_path_t *dp)
-{
-  while (1)
-    {
-      grub_efi_uint8_t type;
-      grub_efi_uint8_t subtype; 
-
-      if (GRUB_EFI_END_ENTIRE_DEVICE_PATH (dp))
-        break;
-
-      type = GRUB_EFI_DEVICE_PATH_TYPE (dp);
-      subtype = GRUB_EFI_DEVICE_PATH_SUBTYPE (dp);
-
-      if (type == GRUB_EFI_MEDIA_DEVICE_PATH_TYPE && subtype == GRUB_EFI_FILE_PATH_DEVICE_PATH_SUBTYPE)
-	return dp;
-
-      dp = GRUB_EFI_NEXT_DEVICE_PATH (dp);
-    }
-
-  return NULL;
-}
-
 static grub_efi_boolean_t
 handle_image (struct grub_secureboot_chainloader_context *load_context)
 {
@@ -881,6 +881,12 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),
     }
   loaded_image->device_handle = dev_handle;
 
+  if (! loaded_image->file_path)
+    {
+      grub_dprintf ("chain", "bailout file_path\n");
+      loaded_image->file_path = grub_efi_get_media_file_path (file_path);
+    }
+
   /* Build load options with arguments from chainloader command line. */
   if (cmdline)
     {
-- 
2.49.0