AppArmor: fix oops in apparmor_setprocattr

When invalid parameters are passed to apparmor_setprocattr a NULL deref
oops occurs when it tries to record an audit message. This is because
it is passing NULL for the profile parameter for aa_audit. But aa_audit
now requires that the profile passed is not NULL.

Fix this by passing the current profile on the task that is trying to
setprocattr.

Signed-off-by: Kees Cook <kees@ubuntu.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Cc: stable@kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
static int apparmor_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
			       mode_t mode)
{
	if (!mediated_filesystem(dentry->d_inode))
		return 0;

	return common_perm_mnt_dentry(OP_CHMOD, mnt, dentry, AA_MAY_CHMOD);
}

static int apparmor_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
			       mode_t mode)
{
	if (!mediated_filesystem(dentry->d_inode))
		return 0;

	return common_perm_mnt_dentry(OP_CHMOD, mnt, dentry, AA_MAY_CHMOD);
}
