new file mode 100644
@@ -0,0 +1,79 @@
+Upstream-Status: Pending [Not submitted to upstream yet]
+Signed-off-by: Vishnu Banavath <vishnu.banavath@arm.com>
+
+From c88937f3fb2d1259b1abb1a6926e869bf2f5d69e Mon Sep 17 00:00:00 2001
+From: Vishnu Banavath <vishnu.banavath@arm.com>
+Date: Fri, 24 Dec 2021 19:17:17 +0000
+Subject: [PATCH] smm_gateway: add checks for null attributes
+
+As par EDK-2 and EDK-2 test code, when a user issue's
+setVariable() with 0 in attributes field, it means a variable
+delete request. Currently, smm gatway doesn't handle this scenario.
+This change is to add that support
+
+Signed-off-by: Vishnu Banavath <vishnu.banavath@arm.com>
+
+diff --git a/components/service/smm_variable/backend/uefi_variable_store.c b/components/service/smm_variable/backend/uefi_variable_store.c
+index a57b334..e8771c2 100644
+--- a/components/service/smm_variable/backend/uefi_variable_store.c
++++ b/components/service/smm_variable/backend/uefi_variable_store.c
+@@ -167,7 +167,9 @@ efi_status_t uefi_variable_store_set_variable(
+ * EFI_VARIABLE_RUNTIME_ACCESS set must also have EFI_VARIABLE_BOOTSERVICE_ACCESS set.
+ * The caller is responsible for following this rule.
+ */
+- if((var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS))
++ if (!var->Attributes)
++ EMSG("It might be a delete variable request\n");
++ else if((var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS))
+ {
+ if((var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS) != EFI_VARIABLE_BOOTSERVICE_ACCESS )
+ return EFI_INVALID_PARAMETER;
+@@ -191,7 +193,7 @@ efi_status_t uefi_variable_store_set_variable(
+ (var->Attributes & EFI_VARIABLE_NON_VOLATILE) ||
+ (info->is_variable_set && (info->metadata.attributes & EFI_VARIABLE_NON_VOLATILE));
+
+- if (var->DataSize) {
++ if (var->DataSize && var->Attributes) {
+
+ /* It's a set rather than a remove operation */
+ variable_index_update_variable(
+@@ -206,7 +208,9 @@ efi_status_t uefi_variable_store_set_variable(
+ * that it's never possible for an object to exist within
+ * the storage backend without a corresponding index entry.
+ */
+- remove_variable_data(context, info);
++ EMSG(" deleting variable %s \n",var->Name);
++ if (remove_variable_data(context, info) != PSA_SUCCESS)
++ EMSG(" deleting variable %s FAILED\n",var->Name);
+ variable_index_remove_variable(&context->variable_index, info);
+
+ /* Variable info no longer valid */
+@@ -587,14 +591,18 @@ static efi_status_t check_access_permitted_on_set(
+ }
+
+ if ((status == EFI_SUCCESS) && var->DataSize) {
+-
++ /* Delete the variable with Attributes is 0 */
++ if (!var->Attributes) {
++ EMSG("Null attributes, may be a delete variable request\n");
++ status = EFI_SUCCESS;
++ }
+ /* Restrict which attributes can be modified for an existing variable */
+- if (((var->Attributes & EFI_VARIABLE_NON_VOLATILE) !=
+- (info->metadata.attributes & EFI_VARIABLE_NON_VOLATILE)) ||
+- ((var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS) !=
+- (info->metadata.attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)) ||
+- ((var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) !=
+- (info->metadata.attributes & EFI_VARIABLE_RUNTIME_ACCESS))) {
++ else if (((var->Attributes & EFI_VARIABLE_NON_VOLATILE) !=
++ (info->metadata.attributes & EFI_VARIABLE_NON_VOLATILE)) ||
++ ((var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS) !=
++ (info->metadata.attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)) ||
++ ((var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) !=
++ (info->metadata.attributes & EFI_VARIABLE_RUNTIME_ACCESS))) {
+ /* Don't permit change of attributes */
+ status = EFI_INVALID_PARAMETER;
+ }
+--
+2.17.1
+
@@ -42,6 +42,7 @@ SRC_URI:append = " \
file://0029-Change-UID-of-variable-index-in-SMM.patch \
file://0030-Add-missing-features-to-setVariable.patch \
file://0031-Add-invalid-parameter-check-in-getNextVariableName.patch \
+ file://0032-smm_gateway-add-checks-for-null-attributes.patch \
"
SRC_URI_MBED = "git://github.com/ARMmbed/mbed-crypto.git;protocol=https;branch=development;name=mbed;destsuffix=git/mbedcrypto"