Subject: 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. Cc: [email protected] Cc: [email protected] Fixes: d50dde5a10f3 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI") Reported-and-Tested-by: Daniel Lezcano <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> --- kernel/sched/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 93a2836b6220..36c951b7eef8 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3296,7 +3296,8 @@ static int __sched_setscheduler(struct task_struct *p, */ 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; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
