From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 In-Reply-To: <995b77557010b2f9aed0e10435f7b8536df7a5db.1521179281.git.rgb@redhat.com> References: <995b77557010b2f9aed0e10435f7b8536df7a5db.1521179281.git.rgb@redhat.com> From: Paul Moore Date: Wed, 18 Apr 2018 20:11:30 -0400 Message-ID: Subject: Re: [RFC PATCH ghak32 V2 02/13] audit: check children and threading before allowing containerid To: Richard Guy Briggs Cc: cgroups@vger.kernel.org, containers@lists.linux-foundation.org, linux-api@vger.kernel.org, Linux-Audit Mailing List , linux-fsdevel@vger.kernel.org, LKML , netdev@vger.kernel.org, ebiederm@xmission.com, luto@kernel.org, jlayton@redhat.com, carlos@redhat.com, dhowells@redhat.com, viro@zeniv.linux.org.uk, simo@redhat.com, Eric Paris , serge@hallyn.com Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org List-ID: On Fri, Mar 16, 2018 at 5:00 AM, Richard Guy Briggs 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 > --- > 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