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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
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
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