[PATCH] security: lsm_audit: print pid and tid

[Paul Moore]

On Wed, Aug 17, 2016 at 4:58 PM, Paul Moore <paul at paul-moore.com> wrote:
> On Tue, Jul 26, 2016 at 10:54 AM, Jeff Vander Stoep <jeffv at google.com> wrote:
>> dump_common_audit_data() currently contains a field for pid, but the
>> value printed is actually the thread ID, tid. Update this value to
>> return the task group ID. Add a new field for tid. With this change
>> the values printed by audit now match the values returned by the
>> getpid() and gettid() syscalls.
>>
>> Signed-off-by: Jeff Vander Stoep <jeffv at google.com>
>> ---
>>  security/lsm_audit.c | 7 +++++--
>>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> Hi Jeff,
>
> Have you tested this against the audit-testsuite[1]?  We don't have an
> explicit PID test yet, but at least two of the tests do test it as a
> side effect.
>
> Steve, I don't see the thread ID listed in the field dictionary, are
> you okay with using "tid" for this?
>
> However, as far as I can see, the biggest problem with this patch is
> that it adds a field in the middle of a record which will likely cause
> the audit userspace tools to explode (or so I've been warned in the
> past).  Steve, what say you about the userspace?
>
> [1] https://github.com/linux-audit/audit-testsuite
> [2] https://github.com/linux-audit/audit-documentation/blob/master/specs/fields/field-dictionary.csv

Steve?

>> diff --git a/security/lsm_audit.c b/security/lsm_audit.c
>> index cccbf30..57f26c1 100644
>> --- a/security/lsm_audit.c
>> +++ b/security/lsm_audit.c
>> @@ -220,7 +220,8 @@ static void dump_common_audit_data(struct audit_buffer *ab,
>>          */
>>         BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2);
>>
>> -       audit_log_format(ab, " pid=%d comm=", task_pid_nr(current));
>> +       audit_log_format(ab, " pid=%d tid=%d comm=", task_tgid_vnr(tsk),
>> +                       task_pid_vnr(tsk));
>>         audit_log_untrustedstring(ab, memcpy(comm, current->comm, sizeof(comm)));
>>
>>         switch (a->type) {
>> @@ -294,10 +295,12 @@ static void dump_common_audit_data(struct audit_buffer *ab,
>>         case LSM_AUDIT_DATA_TASK: {
>>                 struct task_struct *tsk = a->u.tsk;
>>                 if (tsk) {
>> -                       pid_t pid = task_pid_nr(tsk);
>> +                       pid_t pid = task_tgid_vnr(tsk);
>>                         if (pid) {
>>                                 char comm[sizeof(tsk->comm)];
>>                                 audit_log_format(ab, " opid=%d ocomm=", pid);
>> +                               audit_log_format(ab, " opid=%d otid=%d ocomm=",
>> +                                               pid, task_pid_vnr(tsk));
>>                                 audit_log_untrustedstring(ab,
>>                                     memcpy(comm, tsk->comm, sizeof(comm)));
>>                         }
>
> --
> paul moore
> www.paul-moore.com

-- 
paul moore
www.paul-moore.com