`man 2 times` mentions tms_stime as the CPU time spent in the system while executing tasks on behalf of the calling process. It is unclear whether this time should account the summary time of all kernel processes or threads executing tasks on behalf of the calling process. In my opinion, it should account the summary time of all kernel processes or threads executing tasks on behalf of the calling process, and this should be documented in the manpage.
I think the issue here is one of ambiguous language in the page: "tasks" here does not correspond to process (or "tasks" in the kernel sense of schedulable entities). It just means "work". To make this clearer, I've ajusted that sentence a little: The tms_stime field contains the CPU time spent executing inside the kernel while performing tasks on behalf of the calling process. Closing this bug now, since I think the problem is address. Please reopen if you still have concerns.