On 2020-01-31 09:50, Steve Grubb wrote: > On Wednesday, January 22, 2020 4:29:12 PM EST Paul Moore wrote: > > On Tue, Dec 31, 2019 at 2:51 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote: > > > Track the parent container of a container to be able to filter and > > > report nesting. > > > > > > Now that we have a way to track and check the parent container of a > > > container, modify the contid field format to be able to report that > > > nesting using a carrat ("^") separator to indicate nesting. The > > > original field format was "contid=<contid>" for task-associated records > > > and "contid=<contid>[,<contid>[...]]" for network-namespace-associated > > > records. The new field format is > > > "contid=<contid>[^<contid>[...]][,<contid>[...]]". > > > > Let's make sure we always use a comma as a separator, even when > > recording the parent information, for example: > > "contid=<contid>[,^<contid>[...]][,<contid>[...]]" > > > > > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx> > > > --- > > > > > > include/linux/audit.h | 1 + > > > kernel/audit.c | 53 > > > +++++++++++++++++++++++++++++++++++++++++++-------- kernel/audit.h > > > | 1 + > > > kernel/auditfilter.c | 17 ++++++++++++++++- > > > kernel/auditsc.c | 2 +- > > > 5 files changed, 64 insertions(+), 10 deletions(-) > > > > ... > > > > > diff --git a/kernel/audit.c b/kernel/audit.c > > > index ef8e07524c46..68be59d1a89b 100644 > > > --- a/kernel/audit.c > > > +++ b/kernel/audit.c > > > > > > @@ -492,6 +493,7 @@ void audit_switch_task_namespaces(struct nsproxy *ns, > > > struct task_struct *p)> > > > audit_netns_contid_add(new->net_ns, contid); > > > > > > } > > > > > > +void audit_log_contid(struct audit_buffer *ab, u64 contid); > > > > If we need a forward declaration, might as well just move it up near > > the top of the file with the rest of the declarations. > > > > > +void audit_log_contid(struct audit_buffer *ab, u64 contid) > > > +{ > > > + struct audit_contobj *cont = NULL, *prcont = NULL; > > > + int h; > > > > It seems safer to pass the audit container ID object and not the u64. > > > > > + if (!audit_contid_valid(contid)) { > > > + audit_log_format(ab, "%llu", contid); > > > > Do we really want to print (u64)-1 here? Since this is a known > > invalid number, would "?" be a better choice? > > The established pattern is that we print -1 when its unset and "?" when its > totalling missing. So, how could this be invalid? It should be set or not. > That is unless its totally missing just like when we do not run with selinux > enabled and a context just doesn't exist. Ok, so in this case it is clearly unset, so should be -1, which will be a 20-digit number when represented as an unsigned long long int. Thank you for that clarification Steve. > -Steve > > > > + return; > > > + } > > > + h = audit_hash_contid(contid); > > > + rcu_read_lock(); > > > + list_for_each_entry_rcu(cont, &audit_contid_hash[h], list) > > > + if (cont->id == contid) { > > > + prcont = cont; > > > > Why not just pull the code below into the body of this if statement? > > It all needs to be done under the RCU read lock anyway and the code > > would read much better this way. > > > > > + break; > > > + } > > > + if (!prcont) { > > > + audit_log_format(ab, "%llu", contid); > > > + goto out; > > > + } > > > + while (prcont) { > > > + audit_log_format(ab, "%llu", prcont->id); > > > + prcont = prcont->parent; > > > + if (prcont) > > > + audit_log_format(ab, "^"); > > > > In the interest of limiting the number of calls to audit_log_format(), > > how about something like the following: > > > > audit_log_format("%llu", cont); > > iter = cont->parent; > > while (iter) { > > if (iter->parent) > > audit_log_format("^%llu,", iter); > > else > > audit_log_format("^%llu", iter); > > iter = iter->parent; > > } > > > > > + } > > > +out: > > > + rcu_read_unlock(); > > > +} > > > + > > > > > > /* > > > > > > * audit_log_container_id - report container info > > > * @context: task or local context for record > > > > ... > > > > > @@ -2705,9 +2741,10 @@ int audit_set_contid(struct task_struct *task, u64 > > > contid)> > > > if (!ab) > > > > > > return rc; > > > > > > - audit_log_format(ab, > > > - "op=set opid=%d contid=%llu old-contid=%llu", > > > - task_tgid_nr(task), contid, oldcontid); > > > + audit_log_format(ab, "op=set opid=%d contid=", > > > task_tgid_nr(task)); + audit_log_contid(ab, contid); > > > + audit_log_format(ab, " old-contid="); > > > + audit_log_contid(ab, oldcontid); > > > > This is an interesting case where contid and old-contid are going to > > be largely the same, only the first (current) ID is going to be > > different; do we want to duplicate all of those IDs? > > > > > audit_log_end(ab); > > > return rc; > > > > > > } > > > > > > @@ -2723,9 +2760,9 @@ void audit_log_container_drop(void) > > > > 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