Описание
In the Linux kernel, the following vulnerability has been resolved:
sched/core: Call wakeup_preempt() for queued tasks during class change
Paul reported recent RCU changes exposed a lost resched where CPU idles with a rcutorture thread waiting while being completely runnable.
Dumping the rq state at the time of idling with runnable tasks showed the following:
rq->next_class = &fair_sched_class rq->nr_running = 1 rq->cfs.h_nr_queued = 0 rq->rt.rt_nr_running = 1
Although the waiting task was an RT task, "rq->next_class" did not point to rt_sched_class and was stuck at the lower priority fair_sched_class.
Inspecting sched_change_end() revealed the following race with __sched_setscheduler() for queued, but non-running tasks:
__schedule()
EPSS
Дефекты
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: sched/core: Call wakeup_preempt() for queued tasks during class change Paul reported recent RCU changes exposed a lost resched where CPU idles with a rcutorture thread waiting while being completely runnable. Dumping the rq state at the time of idling with runnable tasks showed the following: rq->next_class = &fair_sched_class rq->nr_running = 1 rq->cfs.h_nr_queued = 0 rq->rt.rt_nr_running = 1 Although the waiting task was an RT task, "rq->next_class" did not point to rt_sched_class and was stuck at the lower priority fair_sched_class. Inspecting sched_change_end() revealed the following race with __sched_setscheduler() for queued, but non-running tasks: CPU0 CPU1 ==== ==== __schedule() /* * rq->donor is a fair task that blocks. * rq->next_class = &fair_sched_class */ rq_lock(rq0) pick_next_task() /* nr_running = 0 */ pick_task_fair() sched_balance_...
In the Linux kernel, the following vulnerability has been resolved: sched/core: Call wakeup_preempt() for queued tasks during class change Paul reported recent RCU changes exposed a lost resched where CPU idles with a rcutorture thread waiting while being completely runnable. Dumping the rq state at the time of idling with runnable tasks showed the following: rq->next_class = &fair_sched_class rq->nr_running = 1 rq->cfs.h_nr_queued = 0 rq->rt.rt_nr_running = 1 Although the waiting task was an RT task, "rq->next_class" did not point to rt_sched_class and was stuck at the lower priority fair_sched_class. Inspecting sched_change_end() revealed the following race with __sched_setscheduler() for queued, but non-running tasks: CPU0 CPU1 ==== ==== __schedule() /* * rq->donor is a fair task that blocks. * rq->next_class = &fair_sched_class */ rq_lock(rq0) pick_next_task() /* nr_running = 0 */ pick_task_fair() sched_balance_...
In the Linux kernel, the following vulnerability has been resolved: s ...
In the Linux kernel, the following vulnerability has been resolved: sched/core: Call wakeup_preempt() for queued tasks during class change Paul reported recent RCU changes exposed a lost resched where CPU idles with a rcutorture thread waiting while being completely runnable. Dumping the rq state at the time of idling with runnable tasks showed the following: rq->next_class = &fair_sched_class rq->nr_running = 1 rq->cfs.h_nr_queued = 0 rq->rt.rt_nr_running = 1 Although the waiting task was an RT task, "rq->next_class" did not point to rt_sched_class and was stuck at the lower priority fair_sched_class. Inspecting sched_change_end() revealed the following race with __sched_setscheduler() for queued, but non-running tasks: CPU0 CPU1 ==== ==== __schedule() /* * rq->donor is a fair task that blocks. * rq->next_class = &fair_sched_class */ rq_lock(rq0) pick_next_tas...
EPSS