[libvirt] [PATCH 2/2] apparmor: don't fail on non-apparmor <seclabel>

[Jim Fehlig]

Guido Günther wrote:
> On Fri, Feb 03, 2017 at 10:32:12AM -0700, Jim Fehlig wrote:
>> If the apparmor security driver is loaded/enabled and domain config
>> contains a <seclabel> element whose type attribute is not 'apparmor',
>> starting the domain fails when attempting to label resources such
>> as tap FDs.
>>
>> Many of the apparmor driver entry points attempt to retrieve the
>> apparmor security label from the domain def, returning failure if
>> not found. Functions such as AppArmorSetFDLabel fail even though
>> domain config contains an explicit 'none' secuirty driver, e.g.
>>
>>   <seclabel type='none' model='none'/>
>>
>> Change the entry points to succeed if the domain config <seclabel>
>> is not apparmor. This matches the behavior of the selinux driver.
>>
>> Signed-off-by: Jim Fehlig <jfehlig at suse.com>
>> ---
>>  src/security/security_apparmor.c | 58 ++++++++++++----------------------------
>>  1 file changed, 17 insertions(+), 41 deletions(-)
>>
>> diff --git a/src/security/security_apparmor.c b/src/security/security_apparmor.c
>> index ad50b08..f871e60 100644
>> --- a/src/security/security_apparmor.c
>> +++ b/src/security/security_apparmor.c
>> @@ -289,10 +289,7 @@ reload_profile(virSecurityManagerPtr mgr,
>>      virSecurityLabelDefPtr secdef = virDomainDefGetSecurityLabelDef(
>>                                                  def, SECURITY_APPARMOR_NAME);
>>  
>> -    if (!secdef)
>> -        return rc;
>> -
>> -    if (!secdef->relabel)
>> +    if (!secdef || !secdef->relabel)
>>          return 0;
>>  
>>      if ((profile_name = get_profile_name(def)) == NULL)
>> @@ -435,7 +432,7 @@ AppArmorGenSecurityLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
>>                                                  SECURITY_APPARMOR_NAME);
>>  
>>      if (!secdef)
>> -        return -1;
>> +        return 0;
>>  
>>      if ((secdef->type == VIR_DOMAIN_SECLABEL_STATIC) ||
>>          (secdef->type == VIR_DOMAIN_SECLABEL_NONE))
>> @@ -495,10 +492,7 @@ AppArmorSetSecurityAllLabel(virSecurityManagerPtr mgr,
>>  {
>>      virSecurityLabelDefPtr secdef = virDomainDefGetSecurityLabelDef(def,
>>                                                      SECURITY_APPARMOR_NAME);
>> -    if (!secdef)
>> -        return -1;
>> -
>> -    if (!secdef->relabel)
>> +    if (!secdef || !secdef->relabel)
>>          return 0;
>>  
>>      /* Reload the profile if stdin_path is specified. Note that
>> @@ -559,12 +553,11 @@ AppArmorReleaseSecurityLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
>>  {
>>      virSecurityLabelDefPtr secdef = virDomainDefGetSecurityLabelDef(def,
>>                                                          SECURITY_APPARMOR_NAME);
>> -    if (!secdef)
>> -        return -1;
>> -
>> -    VIR_FREE(secdef->model);
>> -    VIR_FREE(secdef->label);
>> -    VIR_FREE(secdef->imagelabel);
>> +    if (secdef) {
>> +        VIR_FREE(secdef->model);
>> +        VIR_FREE(secdef->label);
>> +        VIR_FREE(secdef->imagelabel);\
> 
> The trailing slash can be dropped here. The rest of th code looks good
> to me.

Opps, thanks for catching that. I've removed it in my local branch.

Do we need someone else with knowledge of the apparmor driver to review and ACK
these changes?

Regards,
Jim