Re: [RFC PATCH ghak32 V2 11/13] audit: add support for containerid to network namespaces

On Fri, Apr 20, 2018 at 4:02 PM, Richard Guy Briggs <rgb(a)redhat.com&gt; wrote: > On 2018-04-18 21:46, Paul Moore wrote: >> On Fri, Mar 16, 2018 at 5:00 AM, Richard Guy Briggs <rgb(a)redhat.com&gt; 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(a)redhat.com&gt; >> > --- >> > 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.

paul moore