On Fri, Mar 16, 2018 at 5:00 AM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote: > Check if a task has existing children or co-threads and refuse to set > the container ID if either are present. Failure to check this could > permit games where a child scratches its parent's back to work around > inheritance and double-setting policy. > > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx> > --- > kernel/auditsc.c | 4 ++++ > 1 file changed, 4 insertions(+) I would just include this in patch 1/2 as I can't think of world where we wouldn't this check. > diff --git a/kernel/auditsc.c b/kernel/auditsc.c > index 29c8482..a6b0a52 100644 > --- a/kernel/auditsc.c > +++ b/kernel/auditsc.c > @@ -2087,6 +2087,10 @@ static int audit_set_containerid_perm(struct task_struct *task, u64 containerid) > /* if we don't have caps, reject */ > if (!capable(CAP_AUDIT_CONTROL)) > return -EPERM; > + /* if task has children or is not single-threaded, deny */ > + if (!list_empty(&task->children) || > + !(thread_group_leader(task) && thread_group_empty(task))) > + return -EPERM; > /* if containerid is unset, allow */ > if (!audit_containerid_set(task)) > return 0; > -- > 1.8.3.1 -- paul moore www.paul-moore.com
