[PATCH 1/1] efi_loader: error handling in efi_disk_add_dev

[Heinrich Schuchardt]

* If an error occurs in efi_disk_add_dev(), don't leak resources.
* If calloc() fails while creating the file system protocol interface,
  signal an error.
* Rename efi_simple_file_system() to efi_create_simple_file_system().
* Drop a little helpful debug message.

Fixes: 2a92080d8c44 ("efi_loader: add file/filesys support")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
 include/efi_loader.h      | 18 +++++++++++++++---
 lib/efi_loader/efi_disk.c | 15 +++++++++------
 lib/efi_loader/efi_file.c | 12 ++++++++----
 3 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/include/efi_loader.h b/include/efi_loader.h
index 3a64eb9c66..4a29ddaef4 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -696,9 +696,21 @@ void efi_signal_event(struct efi_event *event);
 /* return true if the device is removable */
 bool efi_disk_is_removable(efi_handle_t handle);
 
-/* open file system: */
-struct efi_simple_file_system_protocol *efi_simple_file_system(
-		struct blk_desc *desc, int part, struct efi_device_path *dp);
+/**
+ * efi_create_simple_file_system() - create simple file system protocol
+ *
+ * Create a simple file system protocol for a partition.
+ *
+ * @desc:	block device descriptor
+ * @part:	partition number
+ * @dp:		device path
+ * @fsp:	simple file system protocol
+ * Return:	status code
+ */
+efi_status_t
+efi_create_simple_file_system(struct blk_desc *desc, int part,
+			      struct efi_device_path *dp,
+			      struct efi_simple_file_system_protocol **fsp);
 
 /* open file from device-path: */
 struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp);
diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index 46cb5704a7..f0d76113b0 100644
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -487,15 +487,16 @@ static efi_status_t efi_disk_add_dev(
 	 */
 	if ((part || desc->part_type == PART_TYPE_UNKNOWN) &&
 	    efi_fs_exists(desc, part)) {
-		diskobj->volume = efi_simple_file_system(desc, part,
-							 diskobj->dp);
+		ret = efi_create_simple_file_system(desc, part, diskobj->dp,
+						    &diskobj->volume);
+		if (ret != EFI_SUCCESS)
+			goto error;
+
 		ret = efi_add_protocol(&diskobj->header,
 				       &efi_simple_file_system_protocol_guid,
 				       diskobj->volume);
-		if (ret != EFI_SUCCESS) {
-			log_debug("simple FS failed\n");
-			return ret;
-		}
+		if (ret != EFI_SUCCESS)
+			goto error;
 	}
 	diskobj->ops = block_io_disk_template;
 	diskobj->dev_index = dev_index;
@@ -538,6 +539,8 @@ static efi_status_t efi_disk_add_dev(
 	return EFI_SUCCESS;
 error:
 	efi_delete_handle(&diskobj->header);
+	free(diskobj->volume);
+	free(diskobj);
 	return ret;
 }
 
diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c
index 520c730220..3764a92b50 100644
--- a/lib/efi_loader/efi_file.c
+++ b/lib/efi_loader/efi_file.c
@@ -1192,18 +1192,22 @@ efi_open_volume(struct efi_simple_file_system_protocol *this,
 	return EFI_EXIT(efi_open_volume_int(this, root));
 }
 
-struct efi_simple_file_system_protocol *
-efi_simple_file_system(struct blk_desc *desc, int part,
-		       struct efi_device_path *dp)
+efi_status_t
+efi_create_simple_file_system(struct blk_desc *desc, int part,
+			      struct efi_device_path *dp,
+			      struct efi_simple_file_system_protocol **fsp)
 {
 	struct file_system *fs;
 
 	fs = calloc(1, sizeof(*fs));
+	if (!fs)
+		return EFI_OUT_OF_RESOURCES;
 	fs->base.rev = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION;
 	fs->base.open_volume = efi_open_volume;
 	fs->desc = desc;
 	fs->part = part;
 	fs->dp = dp;
+	*fsp = &fs->base;
 
-	return &fs->base;
+	return EFI_SUCCESS;
 }
-- 
2.40.1