Re: Logging Denials

[Zdenek Pytela]

On Wed, Jun 27, 2018 at 11:00 PM, Sean Hogan <schogan(a)us.ibm.com&gt; wrote:

>  Hello,
>
>  I am not sure this use case has come up before but some our systems are
>  set permissive. I have 3 files I want to have shared with 644 on purpose.
>  The goal is for selinux to allow users(permissive) to read the file but I
>  need a context that will still report an AVC to audit.log as that will be
>  forwarded to a SIEM where rules will be in place to contact security. I
>  have tried auditd_etc_t, var_log_t but nothing ever shows up in audit.log
>  when watching a user cat/vi the files.
>
>  In this situation I actually want to see denials lol but not 100% I am
>  seeing this right. Any help is appreciated.
>
>
>  -rw-r--r--. root root unconfined_u:object_r:auditd_etc_t:s0 fil1.pgp
>  -rw-r--r--. root root unconfined_u:object_r:auditd_etc_t:s0 file2.docx
>  -rw-r--r--. root root unconfined_u:object_r:var_log_t:s0 file3.docx
>  
Hello,

Do you mean access from a user console/shell? SELinux only pays attention
to labels, so it would not be easy to achieve this goal. Can you describe
the use case? Maybe you just need to use audit watch rules:

  # auditctl -w /path/file1 -p r -k secure-access

which will subsequently audit each read access as

type=SYSCALL msg=audit(1530272932.863:1867): arch=c000003e syscall=2
success=yes exit=3 a0=7ffcfb5e6706 a1=0 a2=1fffffffffff0000 a3=7ffcfb5e5730
items=1 ppid=10516 pid=11699 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0
egid=0 sgid=0 fsgid=0 tty=pts0 ses=224 comm="cat" exe="/usr/bin/cat"
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
key="secure-access"
type=CWD msg=audit(1530272932.863:1867):  cwd="/cwd"
type=PATH msg=audit(1530272932.863:1867): item=0 name="/path/file1"
inode=6508 dev=fd:00 mode=0100644 ouid=0 ogid=0 rdev=00:00
obj=unconfined_u:object_r:default_t:s0 objtype=NORMAL
cap_fp=0000000000000000 cap_fi=0000000000000000 cap_fe=0 cap_fver=0
type=PROCTITLE msg=audit(1530272932.863:1867):
proctitle=636174002F706174682F66696C6531

-- 

Zdenek Pytela, Senior technical support engineer and team lead
Customer Engagement and Experience, Red Hat Czech
E-mail: zpytela(a)redhat.com, IRC: zpytela