From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Richard Guy Briggs To: 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 Cc: luto@kernel.org, jlayton@redhat.com, carlos@redhat.com, viro@zeniv.linux.org.uk, dhowells@redhat.com, simo@redhat.com, eparis@parisplace.org, serge@hallyn.com, ebiederm@xmission.com, madzcar@gmail.com, Richard Guy Briggs Subject: [RFC PATCH ghak32 V2 02/13] audit: check children and threading before allowing containerid Date: Fri, 16 Mar 2018 05:00:29 -0400 Message-Id: <995b77557010b2f9aed0e10435f7b8536df7a5db.1521179281.git.rgb@redhat.com> In-Reply-To: References: In-Reply-To: References: Sender: netdev-owner@vger.kernel.org List-ID: 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(+) 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