From: Peter Zijlstra Date: Thu, 16 Jan 2014 16:54:25 +0000 (+0100) Subject: sched: Fix __sched_setscheduler() nice test X-Git-Url: http://pileus.org/git/?a=commitdiff_plain;h=eaad45132c564ce377e6dce05e78e08e456d5315;p=~andy%2Flinux sched: Fix __sched_setscheduler() nice test With the introduction of sched_attr::sched_nice we need to check if we've got permission to actually change the nice value. Daniel found that can_nice() would always fail; and upon inspection it turns out that can_nice() only tests to see if we can lower the nice value, but it doesn't validate if we're lowering or not. Therefore amend the test to only call can_nice() when we lower the nice value. Reported-and-Tested-by: Daniel Lezcano Signed-off-by: Peter Zijlstra Cc: raistlin@linux.it Cc: juri.lelli@gmail.com Cc: Daniel Lezcano Fixes: d50dde5a10f3 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI") Link: http://lkml.kernel.org/r/20140116165425.GA9481@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar --- diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 93a2836b622..36c951b7eef 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3296,7 +3296,8 @@ recheck: */ if (user && !capable(CAP_SYS_NICE)) { if (fair_policy(policy)) { - if (!can_nice(p, attr->sched_nice)) + if (attr->sched_nice < TASK_NICE(p) && + !can_nice(p, attr->sched_nice)) return -EPERM; }