diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2016-03-26 16:15:42 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-08 07:46:02 +0200 |
| commit | 41948f88a521b95e8abc793602015a6d45f52a06 (patch) | |
| tree | efd46586d7ece6f4e98d0f8fe4a47d7372c28d78 | |
| parent | 2faff9d1dfc560da3bfba6a8ab0c30246fd6c1cb (diff) | |
ext4 crypto: use dget_parent() in ext4_d_revalidate()
commit 3d43bcfef5f0548845a425365011c499875491b0 upstream.
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 <viro@ZenIV.linux.org.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/ext4/crypto.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 13a69e0fb90d..1259ade2f10a 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -477,16 +477,21 @@ 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; /* 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 |