Patch "ext4: use file_dentry()" has been added to the 4.5-stable tree

Patch "ext4: use file_dentry()" has been added to the 4.5-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ext4: use file_dentry()

to the 4.5-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-use-file_dentry.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From c0a37d48788475d0a2cf4fbfaa28559a9de612fc Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@redhat.com>
Date: Sat, 26 Mar 2016 16:14:42 -0400
Subject: ext4: use file_dentry()

From: Miklos Szeredi <mszeredi@redhat.com>

commit c0a37d48788475d0a2cf4fbfaa28559a9de612fc upstream.

EXT4 may be used as lower layer of overlayfs and accessing f_path.dentry
can lead to a crash.

Fix by replacing direct access of file->f_path.dentry with the
file_dentry() accessor, which will always return a native object.

Reported-by: Daniel Axtens <dja@axtens.net>
Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Fixes: ff978b09f973 ("ext4 crypto: move context consistency check to ext4_file_open()")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/ext4/file.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -380,7 +380,7 @@ static int ext4_file_open(struct inode *
 			return -ENOKEY;
 	}
 
-	dir = dget_parent(filp->f_path.dentry);
+	dir = dget_parent(file_dentry(filp));
 	if (ext4_encrypted_inode(d_inode(dir)) &&
 	    !ext4_is_child_context_consistent_with_parent(d_inode(dir), inode)) {
 		ext4_warning(inode->i_sb,


Patches currently in stable-queue which might be from mszeredi@redhat.com are

queue-4.5/ext4-use-dget_parent-in-ext4_file_open.patch
queue-4.5/ext4-use-file_dentry.patch
queue-4.5/nfs-use-file_dentry.patch
queue-4.5/fs-add-file_dentry.patch