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Commit 3d43bcfe authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

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: 28b4c263
Reported-by: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
parent c0a37d48

fs/ext4/crypto.c

+8 −4
Original line number Diff line number Diff line
@@ -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