On Wed, Jun 25, 2014 at 11:07 AM, Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
> On 06/24, Kees Cook wrote:
>>
>> +static void copy_seccomp(struct task_struct *p)
>> +{
>> +#ifdef CONFIG_SECCOMP
>> + /*
>> + * Must be called with sighand->lock held, which is common to
>> + * all threads in the group. Regardless, nothing special is
>> + * needed for the child since it is not yet in the tasklist.
>> + */
>> + BUG_ON(!spin_is_locked(¤t->sighand->siglock));
>> +
>> + get_seccomp_filter(current);
>> + p->seccomp = current->seccomp;
>> +
>> + if (p->seccomp.mode != SECCOMP_MODE_DISABLED)
>> + set_tsk_thread_flag(p, TIF_SECCOMP);
>> +#endif
>> +}
>
> Wait. But what about no_new_privs? We should copy it as well...
>
> Perhaps this helper should be updated a bit and moved into seccomp.c so
> that seccomp_sync_threads() could use it too.
Ah! Yes. I had been thinking it had been copied during the task_struct
duplication, but that would have been before holding sighand->lock, so
it needs explicit recopying. Thanks!
-Kees
--
Kees Cook
Chrome OS Security
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