From 548e2dbf6511cc004c647657e43e848b83a19d2b Mon Sep 17 00:00:00 2001
From: Minos Galanakis <minos.galanakis@arm.com>
Date: Mon, 2 Jun 2025 14:17:38 +0100
Subject: [PATCH] Built-in lms driver: Added input guard

Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
---
 library/lms.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/library/lms.c b/library/lms.c
index 7f7bec068b..4bdfd434ad 100644
--- a/library/lms.c
+++ b/library/lms.c
@@ -242,6 +242,10 @@ int mbedtls_lms_import_public_key(mbedtls_lms_public_t *ctx,
     mbedtls_lms_algorithm_type_t type;
     mbedtls_lmots_algorithm_type_t otstype;
 
+    if (key_size < 4) {
+        return MBEDTLS_ERR_LMS_BAD_INPUT_DATA;
+    }
+
     type = (mbedtls_lms_algorithm_type_t) MBEDTLS_GET_UINT32_BE(key, PUBLIC_KEY_TYPE_OFFSET);
     if (type != MBEDTLS_LMS_SHA256_M32_H10) {
         return MBEDTLS_ERR_LMS_BAD_INPUT_DATA;