RE: [EXT] Re: 128 Character limit on proctitle field?
Spotted the EXECVE arguments as well, I'll definitely need to look here since the
proctitle is limited to 128 chars. Appreciate the feedback and info, thanks!
-----Original Message-----
From: Steve Grubb <sgrubb(a)redhat.com>
Sent: Tuesday, September 19, 2023 7:32 PM
To: linux-audit(a)redhat.com
Cc: Wieprecht, Karen M. <Karen.Wieprecht(a)jhuapl.edu>
Subject: [EXT] Re: 128 Character limit on proctitle field?
APL external email warning: Verify sender sgrubb(a)redhat.com before clicking links or
attachments
On Friday, September 15, 2023 12:15:12 PM EDT Wieprecht, Karen M. wrote:
We're working with Docker and podman, and I'm working on
parsing the
audit data we get to flag prohibited and missing command options based on STIG
guidelines. I normally extract the proctitle from the raw auditd data ,
but these commands are very long with sometimes 23 or more command
line parameters , and I noticed that all of the auditd proctitle data
for the lengthier commands is being cut off at 128 characters.
The proctitle event commit message explains why it was created:
https://listman.redhat.com/archives/linux-audit/2014-February/008778.html
The comm field is only 16 characters long. So, it tries to capture the first
128 bytes so that at least android comm fields can be deduced since they are almost always
larger than 16 bytes.
I'm bringing this up for two reasons:
One, not everyone working with this data may realize that there
seems to be a character limit, and second, if this is by chance a bug
as opposed to intentional, then I'm hoping we can get a fix cooking for it?
The record that contains all of the command line is the execve record. It has all
parameters even if it's 10,000. So, you may want to try auditing by exec of specific
applications to get everything.
Also, as mentioned in the commit, proctitle is based off of comm. This can be controlled
by user space to misdirect attention by spoof the program name.
In the meantime, I may be able to work around this by piecing
together the full command from the "a#= " fields, but it would be
much easier if proctitle wasn't cut off after 128 chars.
Thanks, any info you can share would be much appreciated,
This was intentional. There was a long discussion of this in January and February of 2014
if you want more background.
-Steve