diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 038e428b5173..aecf8ee50c37 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -596,6 +596,7 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
 	 */
 	kfree(ses->auth_key.response);
 	ses->auth_key.response = NULL;
+	ses->auth_key.len = 0;
 
 	/*
 	 * If memory allocation is successful, caller of this function
@@ -756,6 +757,7 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
 			rc = server->ops->generate_signingkey(ses);
 			kfree(ses->auth_key.response);
 			ses->auth_key.response = NULL;
+			ses->auth_key.len = 0;
 			if (rc) {
 				cifs_dbg(FYI,
 					"SMB3 session key generation failed\n");
@@ -780,6 +782,7 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
 	if (!server->sign) {
 		kfree(ses->auth_key.response);
 		ses->auth_key.response = NULL;
+		ses->auth_key.len = 0;
 	}
 	kfree(ses->ntlmssp);