Bug 3031

Summary:	Inconsistent PID-values in wtmp file, for root sessions.
Product:	Portable OpenSSH	Reporter:	Lőrinczy Zsigmond <lzsiga>
Component:	sshd	Assignee:	Assigned to nobody <unassigned-bugs>
Status:	NEW ---
Severity:	minor	CC:	lzsiga
Priority:	P5
Version:	8.0p1
Hardware:	Other
OS:	AIX

Description Lőrinczy Zsigmond 2019-07-06 02:04:20 AEST

Inconsistent PID-values in wtmp file, for root sessions.

In case of root-sessions (unlike normal-user-sessions),
functions login(3) and logout(3)+logwtmp(3) are called
by different processes.
(These three functions come from library 'libutil'.)

Both login(3) and logwtmp(3) call getpid(2) to get
the PID of the current process to store into file 'wtmp'
(field 'ut_pid' in struct 'utmp').

Command last(1), at least on Linux, doesn't seem to care,
it still finds the matching login-logout pairs, based on field 'ut_line'.

On the other hand, last(1) on AIX doesn't work this way:
it doesn't recognise the pairs, so according to it
root-sessions are never closed, they are "still logged on" for good.

The only work-around I could come up with is configure-option
'-disable-libutil'.

I hope you could find a way to make these values match
(ie calling login(3) and logout(3)+logwtmp(3) from the same process).

Thank you for your attention.

Regards: Lorinczy Zsigmond