From ff6af6eede200503c58250821d1285f94039eef7 Mon Sep 17 00:00:00 2001
From: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Date: Wed, 16 Mar 2022 17:13:37 +0200
Subject: [PATCH] efi_loader: Set variable attributes when EFI_BUFFER_TOO_SMALL
is returned
Starting UEFI Spec 2.8 we must fill in the variable attributes when
GetVariable() returns EFI_BUFFER_TOO_SMALL and Attributes is non-NULL.
This code was written with 2.7 in mind so let's move the code around a
bit and fill in the attributes EFI_BUFFER_TOO_SMALL is returned
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
---
lib/efi_loader/efi_variable_tee.c | 31 ++++++++++++++++++++-----------
1 file changed, 20 insertions(+), 11 deletions(-)
diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
index 58931c4efd..dfef18435d 100644
--- a/lib/efi_loader/efi_variable_tee.c
+++ b/lib/efi_loader/efi_variable_tee.c
@@ -368,7 +368,7 @@ efi_status_t efi_get_variable_int(const u16 *variable_name,
efi_uintn_t name_size;
efi_uintn_t tmp_dsize;
u8 *comm_buf = NULL;
- efi_status_t ret;
+ efi_status_t ret, tmp;
if (!variable_name || !vendor || !data_size) {
ret = EFI_INVALID_PARAMETER;
@@ -407,23 +407,32 @@ efi_status_t efi_get_variable_int(const u16 *variable_name,
/* Communicate */
ret = mm_communicate(comm_buf, payload_size);
- if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) {
- /* Update with reported data size for trimmed case */
- *data_size = var_acc->data_size;
- }
- if (ret != EFI_SUCCESS)
- goto out;
-
- ret = get_property_int(variable_name, name_size, vendor, &var_property);
- if (ret != EFI_SUCCESS)
+ if (ret != EFI_SUCCESS && ret != EFI_BUFFER_TOO_SMALL)
goto out;
+ /* Update with reported data size for trimmed case */
+ *data_size = var_acc->data_size;
+ /*
+ * UEFI > 2.7 needs the attributes set even if the buffer is
+ * smaller
+ */
if (attributes) {
+ tmp = get_property_int(variable_name, name_size, vendor,
+ &var_property);
+ if (tmp != EFI_SUCCESS) {
+ ret = tmp;
+ goto out;
+ }
*attributes = var_acc->attr;
- if (var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY)
+ if (var_property.property &
+ VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY)
*attributes |= EFI_VARIABLE_READ_ONLY;
}
+ /* return if ret is EFI_BUFFER_TOO_SMALL */
+ if (ret != EFI_SUCCESS)
+ goto out;
+
if (data)
memcpy(data, (u8 *)var_acc->name + var_acc->name_size,
var_acc->data_size);
--
2.39.5