This is a note to let you know that I've just added the patch titled
ext4 crypto: use dget_parent() in ext4_d_revalidate()
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-crypto-use-dget_parent-in-ext4_d_revalidate.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3d43bcfef5f0548845a425365011c499875491b0 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@xxxxxxx>
Date: Sat, 26 Mar 2016 16:15:42 -0400
Subject: ext4 crypto: use dget_parent() in ext4_d_revalidate()
From: Theodore Ts'o <tytso@xxxxxxx>
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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/crypto.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -477,16 +477,21 @@ uint32_t ext4_validate_encryption_key_si
*/
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
Patches currently in stable-queue which might be from tytso@xxxxxxx are
queue-4.4/ext4-fscrypto-avoid-rcu-lookup-in-d_revalidate.patch
queue-4.4/ext4-crypto-revalidate-dentry-after-adding-or-removing-the-key.patch
queue-4.4/ext4-crypto-use-dget_parent-in-ext4_d_revalidate.patch
queue-4.4/ext4-require-encryption-feature-for-ext4_ioc_set_encryption_policy.patch