Re: [PATCH 0/2] namespaces: log namespaces per task

On 14/05/02, Serge E. Hallyn wrote: > Quoting Richard Guy Briggs (rgb(a)redhat.com): >> I saw no replies to my questions when I replied a year after Aris' posting, so >> I don't know if it was ignored or got lost in stale threads: >> https://www.redhat.com/archives/linux-audit/2013-March/msg00020.html >> https://www.redhat.com/archives/linux-audit/2013-March/msg00033.html >> (https://lists.linux-foundation.org/pipermail/containers/2013-March/032063...) >> https://www.redhat.com/archives/linux-audit/2014-January/msg00180.html >> >> I've tried to answer a number of questions that were raised in that thread. >> >> The goal is not quite identical to Aris' patchset. >> >> The purpose is to track namespaces in use by logged processes from the >> perspective of init_*_ns. The first patch defines a function to list them. >> The second patch provides an example of usage for audit_log_task_info() which >> is used by syscall audits, among others. audit_log_task() and >> audit_common_recv_message() would be other potential use cases. >> >> Use a serial number per namespace (unique across one boot of one kernel) >> instead of the inode number (which is claimed to have had the right to change >> reserved and is not necessarily unique if there is more than one proc fs). It >> could be argued that the inode numbers have now become a defacto interface and >> can't change now, but I'm proposing this approach to see if this helps address >> some of the objections to the earlier patchset. >> >> There could also have messages added to track the creation and the destruction >> of namespaces, listing the parent for hierarchical namespaces such as pidns, >> userns, and listing other ids for non-hierarchical namespaces, as well as other >> information to help identify a namespace. >> >> There has been some progress made for audit in net namespaces and pid >> namespaces since this previous thread. net namespaces are now served as peers >> by one auditd in the init_net namespace with processes in a non-init_net >> namespace being able to write records if they are in the init_user_ns and have >> CAP_AUDIT_WRITE. Processes in a non-init_pid_ns can now similarly write >> records. As for CAP_AUDIT_READ, I just posted a patchset to check capabilities >> of userspace processes that try to join netlink broadcast groups. >> >> >> Questions: >> Is there a way to link serial numbers of namespaces involved in migration of a >> container to another kernel? (I had a brief look at CRIU.) Is there a unique >> identifier for each running instance of a kernel? Or at least some identifier >> within the container migration realm? > > Eric Biederman has always been adamantly opposed to adding new namespaces > of namespaces, so the fact that you're asking this question concerns me. I have seen that position and I don't fully understand the justification for it other than added complexity.