Re: [RFC PATCH ghak32 V2 05/13] audit: add containerid support for ptrace and signals

Richard Guy Briggs
2018-04-20T01:03:20Z

On 2018-04-18 20:32, Paul Moore wrote:
> On Fri, Mar 16, 2018 at 5:00 AM, Richard Guy Briggs <rgb@redhat.com> wrote:
> > Add container ID support to ptrace and signals. In particular, the "op"
> > field provides a way to label the auxiliary record to which it is
> > associated.
> >
> > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> > ---
> > include/linux/audit.h | 16 +++++++++++-----
> > kernel/audit.c | 12 ++++++++----
> > kernel/audit.h | 2 ++
> > kernel/auditsc.c | 19 +++++++++++++++----
> > 4 files changed, 36 insertions(+), 13 deletions(-)
>
> ...
>
> > diff --git a/kernel/audit.c b/kernel/audit.c
> > index a12f21f..b238be5 100644
> > --- a/kernel/audit.c
> > +++ b/kernel/audit.c
> > @@ -142,6 +142,7 @@ struct audit_net {
> > kuid_t audit_sig_uid = INVALID_UID;
> > pid_t audit_sig_pid = -1;
> > u32 audit_sig_sid = 0;
> > +u64 audit_sig_cid = INVALID_CID;
> >
> > /* Records can be lost in several ways:
> > 0) [suppressed in audit_alloc]
> > @@ -1438,6 +1439,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
> > memcpy(sig_data->ctx, ctx, len);
> > security_release_secctx(ctx, len);
> > }
> > + sig_data->cid = audit_sig_cid;
> > audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
> > sig_data, sizeof(*sig_data) + len);
> > kfree(sig_data);
> > @@ -2051,20 +2053,22 @@ void audit_log_session_info(struct audit_buffer *ab)
> >
> > /*
> > * audit_log_container_info - report container info
> > - * @tsk: task to be recorded
> > * @context: task or local context for record
> > + * @op: containerid string description
> > + * @containerid: container ID to report
> > */
> > -int audit_log_container_info(struct task_struct *tsk, struct audit_context *context)
> > +int audit_log_container_info(struct audit_context *context,
> > + char *op, u64 containerid)
> > {
> > struct audit_buffer *ab;
> >
> > - if (!audit_containerid_set(tsk))
> > + if (!cid_valid(containerid))
> > return 0;
> > /* Generate AUDIT_CONTAINER_INFO with container ID */
> > ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONTAINER_INFO);
> > if (!ab)
> > return -ENOMEM;
> > - audit_log_format(ab, "contid=%llu", audit_get_containerid(tsk));
> > + audit_log_format(ab, "op=%s contid=%llu", op, containerid);
> > audit_log_end(ab);
> > return 0;
> > }
>
> Let's get these changes into the first patch where
> audit_log_container_info() is defined. Why? This inserts a new field
> into the record which is a no-no. Yes, it is one single patchset, but
> they are still separate patches and who knows which patches a given
> distribution and/or tree may decide to backport.

Fair enough. That first thought went through my mind... Would it be
sufficient to move that field addition to the first patch and leave the
rest here to support trace and signals?

> > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > index 2bba324..2932ef1 100644
> > --- a/kernel/auditsc.c
> > +++ b/kernel/auditsc.c
> > @@ -113,6 +113,7 @@ struct audit_aux_data_pids {
> > kuid_t target_uid[AUDIT_AUX_PIDS];
> > unsigned int target_sessionid[AUDIT_AUX_PIDS];
> > u32 target_sid[AUDIT_AUX_PIDS];
> > + u64 target_cid[AUDIT_AUX_PIDS];
> > char target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
> > int pid_count;
> > };
> > @@ -1422,21 +1423,27 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
> > for (aux = context->aux_pids; aux; aux = aux->next) {
> > struct audit_aux_data_pids *axs = (void *)aux;
> >
> > - for (i = 0; i < axs->pid_count; i++)
> > + for (i = 0; i < axs->pid_count; i++) {
> > + char axsn[sizeof("aux0xN ")];
> > +
> > + sprintf(axsn, "aux0x%x", i);
> > if (audit_log_pid_context(context, axs->target_pid[i],
> > axs->target_auid[i],
> > axs->target_uid[i],
> > axs->target_sessionid[i],
> > axs->target_sid[i],
> > - axs->target_comm[i]))
> > + axs->target_comm[i])
> > + && audit_log_container_info(context, axsn, axs->target_cid[i]))
>
> Shouldn't this be an OR instead of an AND?

Yes. Bash-brain...

> > call_panic = 1;
> > + }
> > }
> >
> > if (context->target_pid &&
> > audit_log_pid_context(context, context->target_pid,
> > context->target_auid, context->target_uid,
> > context->target_sessionid,
> > - context->target_sid, context->target_comm))
> > + context->target_sid, context->target_comm)
> > + && audit_log_container_info(context, "target", context->target_cid))
>
> Same question.

Yes.

> > call_panic = 1;
> >
> > if (context->pwd.dentry && context->pwd.mnt) {
>
> --
> paul moore
> www.paul-moore.com

- RGB

--
Richard Guy Briggs <rgb@redhat.com>
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