CVE-2021-47421

{"id": "CVE-2021-47421", "cveTags": [], "metrics": {}, "published": "2024-05-21T15:15:27.537", "references": [{"url": "https://git.kernel.org/stable/c/248b061689a40f4fed05252ee2c89f87cf26d7d8", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/72e9a1bf9b722628c28092e0c2cd8717edd201dc", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/785cc093b6b5a93cc350421a55f3f1eda6585156", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/248b061689a40f4fed05252ee2c89f87cf26d7d8", "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/72e9a1bf9b722628c28092e0c2cd8717edd201dc", "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Awaiting Analysis", "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume\n\nIn current code, when a PCI error state pci_channel_io_normal is detectd,\nit will report PCI_ERS_RESULT_CAN_RECOVER status to PCI driver, and PCI\ndriver will continue the execution of PCI resume callback report_resume by\npci_walk_bridge, and the callback will go into amdgpu_pci_resume\nfinally, where write lock is releasd unconditionally without acquiring\nsuch lock first. In this case, a deadlock will happen when other threads\nstart to acquire the read lock.\n\nTo fix this, add a member in amdgpu_device strucutre to cache\npci_channel_state, and only continue the execution in amdgpu_pci_resume\nwhen it's pci_channel_io_frozen."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: drm/amdgpu: maneja el caso de pci_channel_io_frozen solo en amdgpu_pci_resume. En el c\u00f3digo actual, cuando se detecta un estado de error de PCI pci_channel_io_normal, informar\u00e1 el estado de PCI_ERS_RESULT_CAN_RECOVER al controlador PCI, y el controlador PCI contin\u00fae la ejecuci\u00f3n de PCI resume callback report_resume mediante pci_walk_bridge, y la devoluci\u00f3n de llamada finalmente ir\u00e1 a amdgpu_pci_resume, donde el bloqueo de escritura se libera incondicionalmente sin adquirir dicho bloqueo primero. En este caso, se producir\u00e1 un punto muerto cuando otros subprocesos comiencen a adquirir el bloqueo de lectura. Para solucionar este problema, agregue un miembro en la estructura amdgpu_device para almacenar en cach\u00e9 pci_channel_state y solo contin\u00fae la ejecuci\u00f3n en amdgpu_pci_resume cuando sea pci_channel_io_frozen."}], "lastModified": "2025-08-28T15:15:36.930", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}