[U-Boot] [PATCH 1/1] efi_loader: SetVariable() deleting variables

[Heinrich Schuchardt]

APPEND_WRITE with data length zero is allowable according to the UEFI
specification.

The EDK2 interpretation of no access attributes is attributes = 0. As
the UEFI specification is vague in this respect let's stick to EDK2 here.

Fixes: commit 6d2f27c5fd60 ("efi_loader: variable: support APPEND_WRITE")
Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
 lib/efi_loader/efi_variable.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 22ad271bd8..4c554c546b 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -443,8 +443,6 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
 	if (ret)
 		goto out;

-#define ACCESS_ATTR (EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS)
-
 	old_val = env_get(native_name);
 	if (old_val) {
 		old_val = parse_attr(old_val, &attr);
@@ -455,7 +453,9 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
 			goto out;
 		}

-		if ((data_size == 0) || !(attributes & ACCESS_ATTR)) {
+		if ((data_size == 0 &&
+		     !(attributes & EFI_VARIABLE_APPEND_WRITE)) ||
+		    !attributes) {
 			/* delete the variable: */
 			env_set(native_name, NULL);
 			ret = EFI_SUCCESS;
@@ -478,8 +478,9 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
 			old_size = 0;
 		}
 	} else {
-		if ((data_size == 0) || !(attributes & ACCESS_ATTR) ||
-		    (attributes & EFI_VARIABLE_APPEND_WRITE)) {
+		if ((data_size == 0 &&
+		     !(attributes & EFI_VARIABLE_APPEND_WRITE)) ||
+		    !attributes) {
 			/* delete, but nothing to do */
 			ret = EFI_NOT_FOUND;
 			goto out;
--
2.23.0