Messages in this thread | | | Date | Mon, 23 Sep 2019 16:54:35 +0200 | From | Thomas Gleixner <> | Subject | [patch V2 0/6] posix-cpu-timers: Fix bogus permission checks |
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When cleaning up posix-cpu-timers I discovered that the permission checks for process clocks and process timers are completely bonkers. The only requirement is that the target PID is a group leader. Which means that any process can read the clocks and attach timers to any other process without priviledge restrictions.
That's just wrong because the clocks and timers can be used to observe behaviour and both reading the clocks and arming timers adds overhead and influences runtime performance of the target process.
Changes vs. V1:
- Address the review comments from Frederic
- Actually return -EPERM when the permission check fails. See patch 6/6 for rationale
V1 can be found here:
https://lore.kernel.org/r/20190905120339.561100423@linutronix.de
I still did not come around to write self tests and won't do so in the next weeks as I'm traveling as of tomorrow and then going on vacation (finally) :)
Thanks,
tglx
--- posix-cpu-timers.c | 71 ++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 49 insertions(+), 22 deletions(-)
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