On 2018-04-20 16:22, Paul Moore wrote: > On Fri, Apr 20, 2018 at 4:02 PM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote: > > On 2018-04-18 21:46, Paul Moore wrote: > >> On Fri, Mar 16, 2018 at 5:00 AM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote: > >> > Audit events could happen in a network namespace outside of a task > >> > context due to packets received from the net that trigger an auditing > >> > rule prior to being associated with a running task. The network > >> > namespace could in use by multiple containers by association to the > >> > tasks in that network namespace. We still want a way to attribute > >> > these events to any potential containers. Keep a list per network > >> > namespace to track these container identifiiers. > >> > > >> > Add/increment the container identifier on: > >> > - initial setting of the container id via /proc > >> > - clone/fork call that inherits a container identifier > >> > - unshare call that inherits a container identifier > >> > - setns call that inherits a container identifier > >> > Delete/decrement the container identifier on: > >> > - an inherited container id dropped when child set > >> > - process exit > >> > - unshare call that drops a net namespace > >> > - setns call that drops a net namespace > >> > > >> > See: https://github.com/linux-audit/audit-kernel/issues/32 > >> > See: https://github.com/linux-audit/audit-testsuite/issues/64 > >> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx> > >> > --- > >> > include/linux/audit.h | 7 +++++++ > >> > include/net/net_namespace.h | 12 ++++++++++++ > >> > kernel/auditsc.c | 9 ++++++--- > >> > kernel/nsproxy.c | 6 ++++++ > >> > net/core/net_namespace.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ > >> > 5 files changed, 76 insertions(+), 3 deletions(-) > > ... > > >> > diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c > >> > index f6c5d33..d9f1090 100644 > >> > --- a/kernel/nsproxy.c > >> > +++ b/kernel/nsproxy.c > >> > @@ -140,6 +140,7 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk) > >> > struct nsproxy *old_ns = tsk->nsproxy; > >> > struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns); > >> > struct nsproxy *new_ns; > >> > + u64 containerid = audit_get_containerid(tsk); > >> > > >> > if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | > >> > CLONE_NEWPID | CLONE_NEWNET | > >> > @@ -167,6 +168,7 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk) > >> > return PTR_ERR(new_ns); > >> > > >> > tsk->nsproxy = new_ns; > >> > + net_add_audit_containerid(new_ns->net_ns, containerid); > >> > return 0; > >> > } > >> > >> Hopefully we can handle this in audit_net_init(), we just need to > >> figure out where we can get the correct task_struct for the audit > >> container ID (some backpointer in the net struct?). > > > > I don't follow. This needs to happen on every task startup. > > audit_net_init() is only called when a new network namespace starts up. > > Yep, sorry, my mistake. I must have confused myself when I was > looking at the code. > > I'm thinking out loud here, bear with me ... > > Assuming we move the netns/audit-container-ID tracking to audit_net, > and considering we already have an audit hook in copy_process() (it > calls audit_alloc()), would this be better handled by the > copy_process() hook? This ignores naming, audit_alloc() reuse, etc.; > those can be easily fixed. I'm just thinking of ways to limit our > impact on the core kernel and leverage our existing interaction > points. The new namespace hasn't been cloned yet and this is the only function where we have access to both namespaces, so I don't see how that could work... > paul moore - RGB -- Richard Guy Briggs <rgb@xxxxxxxxxx> Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635
