From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:56074 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727276AbfCQUHO (ORCPT ); Sun, 17 Mar 2019 16:07:14 -0400 From: Eric Biggers Subject: [PATCH 3/5] fs, fscrypt: clear DCACHE_ENCRYPTED_NAME when unaliasing directory Date: Sun, 17 Mar 2019 13:04:42 -0700 Message-Id: <20190317200444.5967-4-ebiggers@kernel.org> In-Reply-To: <20190317200444.5967-1-ebiggers@kernel.org> References: <20190317200444.5967-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-fscrypt-owner@vger.kernel.org To: linux-fscrypt@vger.kernel.org Cc: 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 List-ID: From: Eric Biggers Make __d_move() clear DCACHE_ENCRYPTED_NAME on the source dentry. This is needed for when d_splice_alias() moves a directory's encrypted alias to its decrypted alias as a result of the encryption key being added. Otherwise, the decrypted alias will incorrectly be invalidated on the next lookup, causing problems such as unmounting a mount the user just mount()ed there. Note that we don't have to support arbitrary moves of this flag because fscrypt doesn't allow dentries with DCACHE_ENCRYPTED_NAME to be the source or target of a rename(). Fixes: 28b4c263961c ("ext4 crypto: revalidate dentry after adding or removing the key") Reported-by: Sarthak Kukreti Signed-off-by: Eric Biggers --- fs/dcache.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/fs/dcache.c b/fs/dcache.c index aac41adf4743..e27d11151d0e 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2718,6 +2718,20 @@ static void copy_name(struct dentry *dentry, struct dentry *target) kfree_rcu(old_name, u.head); } +static void fscrypt_update_flags(struct dentry *dentry) +{ +#ifdef CONFIG_FS_ENCRYPTION + /* + * When d_splice_alias() moves a directory's encrypted alias to its + * decrypted alias as a result of the encryption key being added, + * DCACHE_ENCRYPTED_NAME must be cleared. Note that we don't have to + * support arbitrary moves of this flag because fscrypt doesn't allow + * encrypted aliases to be the source or target of a rename(). + */ + dentry->d_flags &= ~DCACHE_ENCRYPTED_NAME; +#endif +} + /* * __d_move - move a dentry * @dentry: entry to move @@ -2795,6 +2809,7 @@ static void __d_move(struct dentry *dentry, struct dentry *target, list_move(&dentry->d_child, &dentry->d_parent->d_subdirs); __d_rehash(dentry); fsnotify_update_flags(dentry); + fscrypt_update_flags(dentry); write_seqcount_end(&target->d_seq); write_seqcount_end(&dentry->d_seq); -- 2.21.0