[PATCH] efi_loader: Improve the parameter check for QueryVariableInfo()

[Masami Hiramatsu]

Improve efi_query_variable_info() to check the parameter settings
and return correct error code according to the UEFI spec 2.9.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu at linaro.org>
Reported-by: Kazuhiko Sakamoto <sakamoto.kazuhiko at socionext.com>
---
 lib/efi_loader/efi_var_common.c |   20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
index 83479dd142..62aa7f970c 100644
--- a/lib/efi_loader/efi_var_common.c
+++ b/lib/efi_loader/efi_var_common.c
@@ -163,10 +163,28 @@ efi_status_t EFIAPI efi_query_variable_info(
 	EFI_ENTRY("%x %p %p %p", attributes, maximum_variable_storage_size,
 		  remaining_variable_storage_size, maximum_variable_size);
 
-	ret = efi_query_variable_info_int(attributes,
+	if (attributes == 0 || maximum_variable_storage_size == NULL ||
+	    remaining_variable_storage_size == NULL ||
+	    maximum_variable_size == NULL)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	if ((attributes & ~(u32)EFI_VARIABLE_MASK) ||
+	    (attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) ||
+	    (!IS_ENABLED(CONFIG_EFI_SECURE_BOOT) &&
+	     (attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS))) {
+		ret = EFI_UNSUPPORTED;
+	} else if ((attributes & (EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS)) == EFI_VARIABLE_RUNTIME_ACCESS) {
+		/* Runtime accessible variable must also be accessible in bootservices */
+		ret = EFI_INVALID_PARAMETER;
+	} else if ((attributes & (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_HARDWARE_ERROR_RECORD)) == EFI_VARIABLE_HARDWARE_ERROR_RECORD) {
+		/* HW error occurs only on non-volatile variables */
+		ret = EFI_INVALID_PARAMETER;
+	} else {
+		ret = efi_query_variable_info_int(attributes,
 					  maximum_variable_storage_size,
 					  remaining_variable_storage_size,
 					  maximum_variable_size);
+	}
 
 	return EFI_EXIT(ret);
 }