Re: [PATCH v2] TaskTracker : Simplified thread information tracker.

[Steve Grubb <sgrubb@redhat.com>]

On Monday, August 7, 2023 10:24:51 AM EDT Tetsuo Handa wrote:
> On 2023/08/07 7:01, Steve Grubb wrote:
> > This is where the problem begins. We like to have normalized audit
> > records. Meaning that a type of event defines the fields it contains. In
> > this case subject would be a process label. and there is already a
> > precedent for what fields belong in a syscall record.
> 
> What is the definition of "a process label"? SELinux / Smack / AppArmor are
> using security_secid_to_secctx() hook for providing string data for the
> subj= field. I don't think that they are restricting characters that can
> be included. Then, what is wrong with returning subset of ASCII printable
> characters from tt_secid_to_secctx() ?

Typically the label is used for access control decisions. But processes have 
other attributes such as a list of open files. I think adding this information 
will be useful - I'm not opposed to the idea. I am just thinking about how to 
present the information where it is more useful. 

<snip>

> > What I would suggest is to make a separate record: AUDIT_PROC_TREE that
> > describes process tree from the one killed up to the last known parent.
> > This way you can define your own format and SYSCALL can stay as everyone
> > expects it to look. In the EXECVE audit record, there is a precedent of
> > using agv[0]=xx argv[1]=xx argv[2]=yy  and so on. If you want to make
> > these generally parsable without special knowledge of the record format,
> > I'd suggest something like it.
> 
> Yes,
> https://lkml.kernel.org/r/201501202220.DJJ34834.OLJOHFMQOFtSVF@I-love.SAKU
> RA.ne.jp used AUDIT_PROCHISTORY instead of LSM hooks, but that thread died
> there.

I do not read that mail list. AUDIT_PROC_HIST or AUDIT_PROC_CHAIN or some 
thing like that would be the better way to go. If someone wanted to see if 
they have process history for a segfault, how would they do it with the 
proposed record?

ausearch --subject sshd

That just doesn't seem right. If you had a record dedicated to this 
information, then you can do:

ausearch -m PROC_HIST

and it would give you that information. And if you had the data split up 
like: p[0]=xx p[1]=xx p[2]=yy

Then  someone could do this to make a report specific to this:

import auparser as aup
au = aup.AuParser(aup.AUSOURCE_FILE, "audit.log")

au.search_add_expression("type r= PROC_HIST", aup.AUSEARCH_RULE_CLEAR)
au.search_set_stop(aup.AUSEARCH_STOP_RECORD)
while au.search_next_event():
    print("Call chain: ", end="")
    while True:
        print(au.interpret_field(), end = "")
        if au.next_field() == False:
            break
        print("->", end="")

au = None
sys.exit(0)

This would be more programmer friendly.

-Steve


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