From d679f5bec5b329d229dc61fc4cb9f1af4590cb7e Mon Sep 17 00:00:00 2001
From: Aidan Garske <aidan@wolfssl.com>
Date: Thu, 10 Sep 2026 11:35:17 -0700
Subject: [PATCH] F-13530 - Guard the encrypted salt zeroization against a NULL
 buffer

---
 src/fwtpm/fwtpm_command.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/fwtpm/fwtpm_command.c b/src/fwtpm/fwtpm_command.c
index 410c50bf..feb1c86d 100644
--- a/src/fwtpm/fwtpm_command.c
+++ b/src/fwtpm/fwtpm_command.c
@@ -10596,7 +10596,13 @@ static TPM_RC FwCmd_StartAuthSession(FWTPM_CTX* ctx, TPM2_Packet* cmd,
         FwFreeSession(sess);
     }
     TPM2_ForceZero(salt, sizeof(salt));
+#ifdef WOLFTPM_SMALL_STACK
+    if (encSalt != NULL) {
+        TPM2_ForceZero(encSalt, FWTPM_MAX_PUB_BUF);
+    }
+#else
     TPM2_ForceZero(encSalt, FWTPM_MAX_PUB_BUF);
+#endif
     FWTPM_FREE_BUF(encSalt);
     return rc;
 }