[U-Boot] [PATCH] efi_loader: variable: attributes may not be changed if a variable exists

[AKASHI Takahiro]

If a variable already exists, efi_set_variable() should not change
the variable's attributes. This patch enforces it.

Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
 lib/efi_loader/efi_variable.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 37728c3c165d..c4f3a5d2743d 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -450,6 +450,15 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
 			ret = EFI_WRITE_PROTECTED;
 			goto out;
 		}
+
+		/*
+		 * attributes won't be changed
+		 * TODO: take care of APPEND_WRITE once supported
+		 */
+		if (attr != attributes) {
+			ret = EFI_INVALID_PARAMETER;
+			goto out;
+		}
 	}
 
 	val = malloc(2 * data_size + strlen("{ro,run,boot}(blob)") + 1);
-- 
2.21.0