Re: [PATCH ghak90 V5 09/10] audit: add support for containerid to network namespaces

On 2019-03-27 23:42, Ondrej Mosnacek wrote: > On Fri, Mar 15, 2019 at 7:35 PM 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 be 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 audit container identifiiers. > > > > Add/increment the audit container identifier on: > > - initial setting of the audit container identifier via /proc > > - clone/fork call that inherits an audit container identifier > > - unshare call that inherits an audit container identifier > > - setns call that inherits an audit container identifier > > Delete/decrement the audit container identifier on: > > - an inherited audit container identifier 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/92 > > See: https://github.com/linux-audit/audit-testsuite/issues/64 > > See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID > > Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; > > --- > > include/linux/audit.h | 19 ++++++++++++ > > kernel/audit.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++-- > > kernel/nsproxy.c | 4 +++ > > 3 files changed, 106 insertions(+), 3 deletions(-) > > > > diff --git a/include/linux/audit.h b/include/linux/audit.h > > index fa19fa408931..70255c2dfb9f 100644 > > --- a/include/linux/audit.h > > +++ b/include/linux/audit.h > > @@ -27,6 +27,7 @@ > > #include <linux/ptrace.h> > > #include <linux/namei.h> /* LOOKUP_* */ > > #include <uapi/linux/audit.h> > > +#include <linux/refcount.h> > > > > #define AUDIT_INO_UNSET ((unsigned long)-1) > > #define AUDIT_DEV_UNSET ((dev_t)-1) > > @@ -99,6 +100,13 @@ struct audit_task_info { > > > > extern struct audit_task_info init_struct_audit; > > > > +struct audit_contid { > > + struct list_head list; > > + u64 id; > > + refcount_t refcount; > > Hm, since we only ever touch the refcount under a spinlock, I wonder > if we could just make it a regular unsigned int (we don't need the > atomicity guarantees). OTOH, refcount_t comes with some extra overflow > checking, so it's probably better to leave it as is... Since the update is done using rcu-safe methods, do we even need the spin_lock? Neil? Paul?