diff --git a/security/keys/trusted_defined.c b/security/keys/trusted_defined.c
index 7b2179589063..f7d06776faf0 100644
--- a/security/keys/trusted_defined.c
+++ b/security/keys/trusted_defined.c
@@ -148,6 +148,11 @@ static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
 		if (dlen == 0)
 			break;
 		data = va_arg(argp, unsigned char *);
+		if (!data) {
+			ret = -EINVAL;
+			va_end(argp);
+			goto out;
+		}
 		ret = crypto_shash_update(&sdesc->shash, data, dlen);
 		if (ret < 0) {
 			va_end(argp);