fkie_cve-2022-50100
Vulnerability from fkie_nvd
Published
2025-06-18 11:15
Modified
2025-06-18 13:47
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: sched/core: Do not requeue task on CPU excluded from cpus_mask The following warning was triggered on a large machine early in boot on a distribution kernel but the same problem should also affect mainline. WARNING: CPU: 439 PID: 10 at ../kernel/workqueue.c:2231 process_one_work+0x4d/0x440 Call Trace: <TASK> rescuer_thread+0x1f6/0x360 kthread+0x156/0x180 ret_from_fork+0x22/0x30 </TASK> Commit c6e7bd7afaeb ("sched/core: Optimize ttwu() spinning on p->on_cpu") optimises ttwu by queueing a task that is descheduling on the wakelist, but does not check if the task descheduling is still allowed to run on that CPU. In this warning, the problematic task is a workqueue rescue thread which checks if the rescue is for a per-cpu workqueue and running on the wrong CPU. While this is early in boot and it should be possible to create workers, the rescue thread may still used if the MAYDAY_INITIAL_TIMEOUT is reached or MAYDAY_INTERVAL and on a sufficiently large machine, the rescue thread is being used frequently. Tracing confirmed that the task should have migrated properly using the stopper thread to handle the migration. However, a parallel wakeup from udev running on another CPU that does not share CPU cache observes p->on_cpu and uses task_cpu(p), queues the task on the old CPU and triggers the warning. Check that the wakee task that is descheduling is still allowed to run on its current CPU and if not, wait for the descheduling to complete and select an allowed CPU.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/302f7b0fc337746f41c69eb08522907f6a90c643
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/748d2e9585ae53cb6be48e84f93d2f082ae1d135
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/751d4cbc43879229dbc124afefe240b70fd29a85
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fde45283f4c8a91c367ea5f20f87036468755121
Impacted products
Vendor Product Version


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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/core: Do not requeue task on CPU excluded from cpus_mask\n\nThe following warning was triggered on a large machine early in boot on\na distribution kernel but the same problem should also affect mainline.\n\n   WARNING: CPU: 439 PID: 10 at ../kernel/workqueue.c:2231 process_one_work+0x4d/0x440\n   Call Trace:\n    \u003cTASK\u003e\n    rescuer_thread+0x1f6/0x360\n    kthread+0x156/0x180\n    ret_from_fork+0x22/0x30\n    \u003c/TASK\u003e\n\nCommit c6e7bd7afaeb (\"sched/core: Optimize ttwu() spinning on p-\u003eon_cpu\")\noptimises ttwu by queueing a task that is descheduling on the wakelist,\nbut does not check if the task descheduling is still allowed to run on that CPU.\n\nIn this warning, the problematic task is a workqueue rescue thread which\nchecks if the rescue is for a per-cpu workqueue and running on the wrong CPU.\nWhile this is early in boot and it should be possible to create workers,\nthe rescue thread may still used if the MAYDAY_INITIAL_TIMEOUT is reached\nor MAYDAY_INTERVAL and on a sufficiently large machine, the rescue\nthread is being used frequently.\n\nTracing confirmed that the task should have migrated properly using the\nstopper thread to handle the migration. However, a parallel wakeup from udev\nrunning on another CPU that does not share CPU cache observes p-\u003eon_cpu and\nuses task_cpu(p), queues the task on the old CPU and triggers the warning.\n\nCheck that the wakee task that is descheduling is still allowed to run\non its current CPU and if not, wait for the descheduling to complete\nand select an allowed CPU."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: sched/core: No volver a poner en cola la tarea en la CPU excluida de cpus_mask La siguiente advertencia se activ\u00f3 en una m\u00e1quina grande al comienzo del arranque en un kernel de distribuci\u00f3n, pero el mismo problema tambi\u00e9n deber\u00eda afectar a la l\u00ednea principal. ADVERTENCIA: CPU: 439 PID: 10 en ../kernel/workqueue.c:2231 process_one_work+0x4d/0x440 Rastreo de llamadas:  rescuer_thread+0x1f6/0x360 kthread+0x156/0x180 ret_from_fork+0x22/0x30  el commit c6e7bd7afaeb (\"sched/core: Optimize ttwu() spinning on p-\u0026gt;on_cpu\") optimiza ttwu poniendo en cola una tarea que se est\u00e1 desprogramando en la lista de activaci\u00f3n, pero no comprueba si la desprogramaci\u00f3n de tareas a\u00fan puede ejecutarse en esa CPU. En esta advertencia, la tarea problem\u00e1tica es un subproceso de rescate de la cola de trabajo que comprueba si el rescate es para una cola de trabajo por CPU y se ejecuta en la CPU incorrecta. Aunque esto ocurre al principio del arranque y deber\u00eda ser posible crear trabajadores, el hilo de rescate a\u00fan podr\u00eda usarse si se alcanza el tiempo de espera inicial (MAYDAY_INITIAL_TIMEOUT) o el intervalo (MAYDAY_INTERVAL) y, en una m\u00e1quina lo suficientemente grande, se usa con frecuencia. El seguimiento confirm\u00f3 que la tarea deber\u00eda haberse migrado correctamente utilizando el hilo de parada para gestionar la migraci\u00f3n. Sin embargo, una activaci\u00f3n paralela de udev, ejecut\u00e1ndose en otra CPU que no comparte cach\u00e9 de CPU, observa p-\u0026gt;on_cpu y utiliza task_cpu(p), pone la tarea en cola en la CPU anterior y activa la advertencia. Compruebe que la tarea de activaci\u00f3n que se est\u00e1 desprogramando a\u00fan pueda ejecutarse en su CPU actual; de no ser as\u00ed, espere a que se complete la desprogramaci\u00f3n y seleccione una CPU permitida."
    }
  ],
  "id": "CVE-2022-50100",
  "lastModified": "2025-06-18T13:47:40.833",
  "metrics": {},
  "published": "2025-06-18T11:15:39.320",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/302f7b0fc337746f41c69eb08522907f6a90c643"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/748d2e9585ae53cb6be48e84f93d2f082ae1d135"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/751d4cbc43879229dbc124afefe240b70fd29a85"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fde45283f4c8a91c367ea5f20f87036468755121"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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