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| author | Theodore Ts'o | 2016-03-26 21:15:42 +0100 |
|---|---|---|
| committer | Theodore Ts'o | 2016-03-26 21:15:42 +0100 |
| commit | 3d43bcfef5f0548845a425365011c499875491b0 (patch) | |
| tree | d2d0be7090b3e17401a70788e93a2668866c831b | |
| parent | ext4: use file_dentry() (diff) | |
| download | kernel-qcow2-linux-3d43bcfef5f0548845a425365011c499875491b0.tar.gz kernel-qcow2-linux-3d43bcfef5f0548845a425365011c499875491b0.tar.xz kernel-qcow2-linux-3d43bcfef5f0548845a425365011c499875491b0.zip | |
ext4 crypto: use dget_parent() in ext4_d_revalidate()
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>
Cc: stable@vger.kernel.org
| -rw-r--r-- | fs/ext4/crypto.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 012fd3285147..ea69ce4f6d8f 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 |