From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACD76C10F05 for ; Sun, 17 Mar 2019 20:38:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6EEA12087C for ; Sun, 17 Mar 2019 20:38:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727241AbfCQUi0 (ORCPT ); Sun, 17 Mar 2019 16:38:26 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:37674 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726333AbfCQUi0 (ORCPT ); Sun, 17 Mar 2019 16:38:26 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92 #3 (Red Hat Linux)) id 1h5cY2-0003ZP-Lc; Sun, 17 Mar 2019 20:38:22 +0000 Date: Sun, 17 Mar 2019 20:38:22 +0000 From: Al Viro To: Eric Biggers Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, linux-unionfs@vger.kernel.org, Sarthak Kukreti , Gao Xiang Subject: Re: [PATCH 1/5] fscrypt: clean up and improve dentry revalidation Message-ID: <20190317203822.GH2217@ZenIV.linux.org.uk> References: <20190317200444.5967-1-ebiggers@kernel.org> <20190317200444.5967-2-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190317200444.5967-2-ebiggers@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, Mar 17, 2019 at 01:04:40PM -0700, Eric Biggers wrote: > + /* > + * Ciphertext name; valid if the directory's key is still unavailable. > + * > + * Note: since fscrypt forbids rename() on ciphertext names, it should > + * be safe to access ->d_parent directly here. No, it is not. Again, d_splice_alias() on buggered fs image picking a reference to your subdirectory when doing a lookup elsewhere. It can relocate the damn thing, without rename() being allowed for _anything_.