From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Theodore Ts'o To: Ext4 Developers List Cc: dhowells@redhat.com, viro@ZenIV.linux.org.uk, Linux Filesystem Development List , jaegeuk@kernel.org, Theodore Ts'o , stable@vger.kernel.org Subject: [PATCH 5/5] ext4 crypto: use dget_parent() in ext4_d_revalidate() Date: Sat, 26 Mar 2016 17:10:00 -0400 Message-Id: <1459026600-9232-6-git-send-email-tytso@mit.edu> In-Reply-To: <1459026600-9232-1-git-send-email-tytso@mit.edu> References: <1459026600-9232-1-git-send-email-tytso@mit.edu> Sender: stable-owner@vger.kernel.org List-ID: This avoids potential problems caused by a race where the inode gets renamed out from its parent directory and the parent directory is deleted while ext4_d_revalidate() is running. Fixes: 28b4c263961c Reported-by: Al Viro Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org --- fs/ext4/crypto.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 012fd32..ea69ce4 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -478,13 +478,16 @@ uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size) */ static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags) { - struct inode *dir = d_inode(dentry->d_parent); - struct ext4_crypt_info *ci = EXT4_I(dir)->i_crypt_info; + struct dentry *dir; + struct ext4_crypt_info *ci; int dir_has_key, cached_with_key; - if (!ext4_encrypted_inode(dir)) + dir = dget_parent(dentry); + if (!ext4_encrypted_inode(d_inode(dir))) { + dput(dir); return 0; - + } + ci = EXT4_I(d_inode(dir))->i_crypt_info; if (ci && ci->ci_keyring_key && (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) | (1 << KEY_FLAG_REVOKED) | @@ -494,6 +497,7 @@ static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags) /* this should eventually be an flag in d_flags */ cached_with_key = dentry->d_fsdata != NULL; dir_has_key = (ci != NULL); + dput(dir); /* * If the dentry was cached without the key, and it is a -- 2.5.0