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| author | Li Zefan <lizefan@huawei.com> | 2013-05-14 19:44:20 +0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2013-05-14 08:24:15 -0700 |
| commit | d6cbf35dac8a3dadb9103379820c96d7c85df3d9 (patch) | |
| tree | bd25f2bebf2620ab87440e1e8b167e7bf3cdca20 /kernel | |
| parent | f722406faae2d073cc1d01063d1123c35425939e (diff) | |
| download | linux-d6cbf35dac8a3dadb9103379820c96d7c85df3d9.tar.gz linux-d6cbf35dac8a3dadb9103379820c96d7c85df3d9.tar.bz2 linux-d6cbf35dac8a3dadb9103379820c96d7c85df3d9.zip | |
cgroup: initialize xattr before calling d_instantiate()
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@vger.kernel.org> # 3.8.x
Reported-by: Ivan Bulatovic <combuster@archlinux.us>
Reported-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 2a9926275f80..38b136553044 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2699,13 +2699,14 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, goto out; } + cfe->type = (void *)cft; + cfe->dentry = dentry; + dentry->d_fsdata = cfe; + simple_xattrs_init(&cfe->xattrs); + mode = cgroup_file_mode(cft); error = cgroup_create_file(dentry, mode | S_IFREG, cgrp->root->sb); if (!error) { - cfe->type = (void *)cft; - cfe->dentry = dentry; - dentry->d_fsdata = cfe; - simple_xattrs_init(&cfe->xattrs); list_add_tail(&cfe->node, &parent->files); cfe = NULL; } |