On 2/13/19 6:42 PM, Chris PeBenito wrote:
> On 2/12/19 8:05 AM, Sugar, David wrote:
>> I'm seeing a bunch of denials for various processes (some refpolicy
>> domains, some my own application domains) attempting to access
>> /etc/pki. They seem to be working OK even with the denial. Adding
>> interface to dontaudit this stuff and calling the interface.
>>
>> type=AVC msg=audit(1549932300.668:266): avc: denied { search } for
>> pid=7077 comm="X" name="pki" dev="dm-1" ino=138
>> scontext=system_u:system_r:xserver_t:s0-s0:c0.c1023
>> tcontext=system_u:object_r:cert_t:s0 tclass=dir permissive=0
>> type=AVC msg=audit(1549932306.553:430): avc: denied { search } for
>> pid=7345 comm="clamd" name="pki" dev="dm-1" ino=138
>> scontext=system_u:system_r:clamd_t:s0:c1
>> tcontext=system_u:object_r:cert_t:s0 tclass=dir permissive=0
>
> My guess is there is some common library between them (maybe glibc)
> which is triggering this. It seems like this might potentially cover up
> legitimate access. It's just hard to tell by just dir searches.
>
Digging into this I have found a few things, and please note that I am
not seeing this denial in permissive.
Looking at strace for clamd I see an attempt to open the (non-existent)
file /etc/pki/tls/legacy-settings. I think this would explain the
denial on dir search.
If I create that file (even empty) labeled cert_t I see denials (in
permissive) for clamd_t cert_t:file { getattr open read }.
audit2allow suggests the boolean 'authlogin_nsswitch_use_ldap' should
resolve the issue (for clamd_t). This makes sense as clamd uses the
interface auth_use_nsswitch(clamd_t).
So, assuming that I don't want to enable 'authlogin_nsswitch_use_ldap'
is there a way to quiet this denial?
Maybe this has to do with dropping from root to the clamscan user.
Would it be acceptable to apply the patch to miscfiles.if for use in my
application domains but not accept the patches for clamav and xserver?
>
>> Signed-off-by: Dave Sugar <dsugar@xxxxxxxxxx>
>> ---
>> policy/modules/services/clamav.te | 1 +
>> policy/modules/services/xserver.te | 1 +
>> policy/modules/system/miscfiles.if | 20 ++++++++++++++++++++
>> 3 files changed, 22 insertions(+)
>>
>> diff --git a/policy/modules/services/clamav.te
>> b/policy/modules/services/clamav.te
>> index 622453e3..ad19cc7b 100644
>> --- a/policy/modules/services/clamav.te
>> +++ b/policy/modules/services/clamav.te
>> @@ -147,6 +147,7 @@ auth_use_nsswitch(clamd_t)
>> logging_send_syslog_msg(clamd_t)
>> +miscfiles_dontaudit_search_generic_certs(clamd_t)
>> miscfiles_read_localization(clamd_t)
>> tunable_policy(`clamd_use_jit',`
>> diff --git a/policy/modules/services/xserver.te
>> b/policy/modules/services/xserver.te
>> index a2b08a89..da1c0c7d 100644
>> --- a/policy/modules/services/xserver.te
>> +++ b/policy/modules/services/xserver.te
>> @@ -804,6 +804,7 @@ locallogin_use_fds(xserver_t)
>> logging_send_syslog_msg(xserver_t)
>> logging_send_audit_msgs(xserver_t)
>> +miscfiles_dontaudit_search_generic_certs(xserver_t)
>> miscfiles_read_localization(xserver_t)
>> miscfiles_read_fonts(xserver_t)
>> diff --git a/policy/modules/system/miscfiles.if
>> b/policy/modules/system/miscfiles.if
>> index 93c1f9c1..cecdb406 100644
>> --- a/policy/modules/system/miscfiles.if
>> +++ b/policy/modules/system/miscfiles.if
>> @@ -131,6 +131,26 @@ interface(`miscfiles_read_generic_certs',`
>> read_lnk_files_pattern($1, cert_t, cert_t)
>> ')
>> +########################################
>> +## <summary>
>> +## Do not audit attempts to search
>> +## on a generic certs directory.
>> +## </summary>
>> +## <param name="domain">
>> +## <summary>
>> +## Domain to not audit.
>> +## </summary>
>> +## </param>
>> +## <rolecap/>
>> +#
>> +interface(`miscfiles_dontaudit_search_generic_certs',`
>> + gen_require(`
>> + type cert_t;
>> + ')
>> +
>> + dontaudit $1 cert_t:dir search;
>> +')
>> +
>> ########################################
>> ## <summary>
>> ## Manage generic SSL/TLS certificates.
>>
>
>
