Failure flag "0" doesn't work

Burn Alting burn at swtf.dyndns.org
Thu Aug 20 22:15:41 UTC 2015


Alex,

This is a little outside my experience.

One assumes the audit_failure variable has been set in the kernel
(kernel/audit.c). Perhaps you can test this.

Given you can get a copy of the kernel source you are running, perhaps
trace through what's happening. Using the messages
before/during/directly after the death of auditd, and what's routing to
dmesg, perhaps you can reverse engineer what is happening.

Perhaps someone else on the list can explain why, given -f is set to 0,
and the kernel has no user space destination for audit, it still prints
(via printk()?)

Regards

On Thu, 2015-08-20 at 13:17 +0300, Alex Beljanski wrote:
> We have custom audit-dispatcher for process events. On some servers
> when auditd fails, all audit messages writes to kernel. 
> We don't want to see all this messages in dmesg and set failure flag
> to "0". This doesn't help. 
> 
> 
> # cat /etc/audit/auditd.conf
> 
> log_file = /var/log/audit/audit.log
> log_format = NOLOG
> log_group = root
> priority_boost = 4
> flush = none
> num_logs = 1
> disp_qos = lossy
> dispatcher = /sbin/audit-dispatcher
> name_format = none
> max_log_file = 1
> max_log_file_action = keep_logs
> space_left = 75
> space_left_action = ignore
> admin_space_left = 50
> admin_space_left_action = ignore
> disk_full_action = ignore
> disk_error_action = ignore
> enable_krb5 = no
> 
> cat /etc/audit/rules.d/audit.rules 
> 
> -D
> 
> -b 8192
> 
> -f 0
> -e 1
> 
> -a exit,always -F arch=b32 -S 11 -k exec32
> -a exit,always -F arch=b64 -S 59 -k exec64
> 
> 
> 
> 
> 2015-08-20 12:39 GMT+03:00 Burn Alting <burn at swtf.dyndns.org>:
>         Alex,
>         
>         Can you provide a little more detail?
>         
>         Perhaps your /etc/audit/auditd.conf, /etc/audit/rules.d/*,
>         your test
>         case, the expected outcome and the outcome you actually get.
>         
>         Regards
>         
>         On Thu, 2015-08-20 at 11:09 +0300, Alex Beljanski wrote:
>         > Hi!
>         >
>         >
>         > We have problem in CentOS 7 with auditd.
>         >
>         > For our servers we set failure flag 0, but kernel write
>         messages and
>         > we see them in dmesg.
>         >
>         > uname -a
>         > Linux 3.10.0-229.11.1.el7.x86_64 #1 SMP Thu Aug 6 01:06:18
>         UTC 2015
>         > x86_64 x86_64 x86_64 GNU/Linux
>         >
>         > # rpm -qa | grep audit
>         > audit-2.4.1-5.el7.x86_64
>         >
>         >
>         > Why this doesn't work?
>         >
>         >
>         >
>         >
>         >
>         
>         > --
>         > Linux-audit mailing list
>         > Linux-audit at redhat.com
>         > https://www.redhat.com/mailman/listinfo/linux-audit
>         
>         
> 
> 





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