[PATCH] efi_loader: check update capsule parameters

[Vincent Stehlé]

UpdateCapsule() must return EFI_INVALID_PARAMETER in a number of cases,
listed by the UEFI specification and tested by the SCT. Add a common
function to do that.

This fixes SCT UpdateCapsule_Conf failures.

Reviewed-by: Grant Likely <grant.likely at arm.com>
Signed-off-by: Vincent Stehlé <vincent.stehle at arm.com>
Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
Cc: Alexander Graf <agraf at csgraf.de>
---
 include/efi_loader.h         | 24 ++++++++++++++++++++++++
 lib/efi_loader/efi_capsule.c |  8 ++++----
 lib/efi_loader/efi_runtime.c |  8 ++++++++
 3 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/include/efi_loader.h b/include/efi_loader.h
index 0a9c82a257e..426d1c72d7d 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -910,6 +910,30 @@ extern const struct efi_firmware_management_protocol efi_fmp_fit;
 extern const struct efi_firmware_management_protocol efi_fmp_raw;
 
 /* Capsule update */
+static inline efi_status_t
+efi_valid_update_capsule_params(struct efi_capsule_header
+						**capsule_header_array,
+				efi_uintn_t capsule_count,
+				u64 scatter_gather_list)
+{
+	u32 flags;
+
+	if (!capsule_count)
+		return EFI_INVALID_PARAMETER;
+
+	flags = capsule_header_array[0]->flags;
+
+	if (((flags & CAPSULE_FLAGS_PERSIST_ACROSS_RESET) &&
+	     !scatter_gather_list) ||
+	    ((flags & CAPSULE_FLAGS_POPULATE_SYSTEM_TABLE) &&
+	     !(flags & CAPSULE_FLAGS_PERSIST_ACROSS_RESET)) ||
+	    ((flags & CAPSULE_FLAGS_INITIATE_RESET) &&
+	     !(flags & CAPSULE_FLAGS_PERSIST_ACROSS_RESET)))
+		return EFI_INVALID_PARAMETER;
+
+	return EFI_SUCCESS;
+}
+
 efi_status_t EFIAPI efi_update_capsule(
 		struct efi_capsule_header **capsule_header_array,
 		efi_uintn_t capsule_count,
diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
index 60309d4a07d..380cfd70290 100644
--- a/lib/efi_loader/efi_capsule.c
+++ b/lib/efi_loader/efi_capsule.c
@@ -442,12 +442,12 @@ efi_status_t EFIAPI efi_update_capsule(
 	EFI_ENTRY("%p, %zu, %llu\n", capsule_header_array, capsule_count,
 		  scatter_gather_list);
 
-	if (!capsule_count) {
-		ret = EFI_INVALID_PARAMETER;
+	ret = efi_valid_update_capsule_params(capsule_header_array,
+					      capsule_count,
+					      scatter_gather_list);
+	if (ret != EFI_SUCCESS)
 		goto out;
-	}
 
-	ret = EFI_SUCCESS;
 	for (i = 0, capsule = *capsule_header_array; i < capsule_count;
 	     i++, capsule = *(++capsule_header_array)) {
 		/* sanity check */
diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
index 93a695fc27e..449ad8b9f36 100644
--- a/lib/efi_loader/efi_runtime.c
+++ b/lib/efi_loader/efi_runtime.c
@@ -467,6 +467,14 @@ efi_status_t __efi_runtime EFIAPI efi_update_capsule_unsupported(
 			efi_uintn_t capsule_count,
 			u64 scatter_gather_list)
 {
+	efi_status_t ret;
+
+	ret = efi_valid_update_capsule_params(capsule_header_array,
+					      capsule_count,
+					      scatter_gather_list);
+	if (ret != EFI_SUCCESS)
+		return ret;
+
 	return EFI_UNSUPPORTED;
 }
 
-- 
2.30.2