diff --git a/libcli/smb/smb2_signing.c b/libcli/smb/smb2_signing.c
index d036fd95918..c808f0bda15 100644
--- a/libcli/smb/smb2_signing.c
+++ b/libcli/smb/smb2_signing.c
@@ -773,12 +773,19 @@ NTSTATUS smb2_signing_decrypt_pdu(struct smb2_signing_key *decryption_key,
 						ctext_size,
 						ptext,
 						&ptext_size);
-		if (rc < 0 || ptext_size != m_total) {
+		if (rc < 0) {
 			TALLOC_FREE(ptext);
 			TALLOC_FREE(ctext);
 			status = gnutls_error_to_ntstatus(rc, NT_STATUS_INTERNAL_ERROR);
 			goto out;
 		}
+		if (ptext_size != m_total) {
+			TALLOC_FREE(ptext);
+			TALLOC_FREE(ctext);
+			rc = GNUTLS_E_SHORT_MEMORY_BUFFER;
+			status = gnutls_error_to_ntstatus(rc, NT_STATUS_INTERNAL_ERROR);
+			goto out;
+		}
 
 		len = 0;
 		for (i = 1; i < count; i++) {