[PATCH] cgroup: initialize xattr before calling d_instantiate()

[Tejun Heo]

On Tue, May 14, 2013 at 07:44:20PM +0800, Li Zefan wrote:
> cgroup_create_file() calls d_instantiate(), which may decide to look
> at the xattrs on the file. Smack always does this and SELinux can be
> configured to do so.
> 
> But cgroup_add_file() didn't initialize xattrs before calling
> cgroup_create_file(), which finally leads to dereferencing NULL
> dentry->d_fsdata.
> 
> This bug has been there since cgroup xattr was introduced.
> 
> Cc: <stable at vger.kernel.org> # 3.8.x
> Reported-by: Ivan Bulatovic <combuster at archlinux.us>
> Reported-by: Casey Schaufler <casey at schaufler-ca.com>
> Signed-off-by: Li Zefan <lizefan at huawei.com>

Applied to cgroup/for-3.10-fixes.

Thanks.

-- 
tejun