Messages in this thread | | | Date | Tue, 7 Feb 2017 23:48:45 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: /proc/timer_list leaks the real pids of the associated processes |
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On Fri, 3 Feb 2017, Kees Cook wrote:
> On Fri, Feb 3, 2017 at 2:29 PM, Xing Gao <xgao01@email.wm.edu> wrote: > > Dear Thomas and Kees, > > > > I posted a bug report on bugzilla, and John asked me to send it the lkml. > > > > Here is the link, https://bugzilla.kernel.org/show_bug.cgi?id=193921 > > > > Please cc to me when you reply this email. > > > > And please check the information below. > > > > The pseudo file /proc/timer_list leaks the real pids of the associated > > processes. > > > > The function print_timer(kernel/time/timer_list.c) displays > > timer->start_pid, which is set inside the function > > __timer_stats_timer_set_start_info (kernel/time/timer.c). This is the real > > pid, rather than the pid in the pid namespace. If the user within a > > container retrieves the content of /proc/timer_list, this file will leak the > > real pid of the associated process. > > I feel like this has been pointed out before, but I can't find the > email about it. Regardless, yeah, this looks true: > > SEQ_printf(m, ", %s/%d", tmp, timer->start_pid); > > #11: <0000000000000000>, hrtimer_wakeup, S:01, do_nanosleep, cron/2570 > > Seems like this should be made namespace aware... (and why is this > file needed at all? Seems like it should live in debugfs not proc).
I'm fine with that.
The TIMER_STATS stuff should go away completely. If people are interested in that information they can use the tracer which gives way better data than that file.
Thanks,
tglx .
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