[PATCH 4.4 169/192] ovl: remove posix_acl_default from workdir

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <mszer...@redhat.com>

commit c11b9fdd6a612f376a5e886505f1c54c16d8c380 upstream.

Clear out posix acl xattrs on workdir and also reset the mode after
creation so that an inherited sgid bit is cleared.

Signed-off-by: Miklos Szeredi <mszer...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/overlayfs/super.c |   19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -763,6 +763,10 @@ retry:
                struct kstat stat = {
                        .mode = S_IFDIR | 0,
                };
+               struct iattr attr = {
+                       .ia_valid = ATTR_MODE,
+                       .ia_mode = stat.mode,
+               };
 
                if (work->d_inode) {
                        err = -EEXIST;
@@ -778,6 +782,21 @@ retry:
                err = ovl_create_real(dir, work, &stat, NULL, NULL, true);
                if (err)
                        goto out_dput;
+
+               err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT);
+               if (err && err != -ENODATA)
+                       goto out_dput;
+
+               err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_ACCESS);
+               if (err && err != -ENODATA)
+                       goto out_dput;
+
+               /* Clear any inherited mode bits */
+               inode_lock(work->d_inode);
+               err = notify_change(work, &attr, NULL);
+               inode_unlock(work->d_inode);
+               if (err)
+                       goto out_dput;
        }
 out_unlock:
        mutex_unlock(&dir->i_mutex);