CVE-2024-49964

{"id": "CVE-2024-49964", "cveTags": [], "metrics": {}, "published": "2024-10-21T18:15:17.510", "references": [{"url": "https://git.kernel.org/stable/c/59e081ff2e91bbf19b8c1ecb75b031f778858383", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c56b6f3d801d7ec8965993342bdd9e2972b6cb8e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Awaiting Analysis", "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix memfd_pin_folios free_huge_pages leak\n\nmemfd_pin_folios followed by unpin_folios fails to restore free_huge_pages\nif the pages were not already faulted in, because the folio refcount for\npages created by memfd_alloc_folio never goes to 0. memfd_pin_folios\nneeds another folio_put to undo the folio_try_get below:\n\nmemfd_alloc_folio()\n alloc_hugetlb_folio_nodemask()\n dequeue_hugetlb_folio_nodemask()\n dequeue_hugetlb_folio_node_exact()\n folio_ref_unfreeze(folio, 1); ; adds 1 refcount\n folio_try_get() ; adds 1 refcount\n hugetlb_add_to_page_cache() ; adds 512 refcount (on x86)\n\nWith the fix, after memfd_pin_folios + unpin_folios, the refcount for the\n(unfaulted) page is 512, which is correct, as the refcount for a faulted\nunpinned page is 513."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm/hugetlb: se corrige la fuga de free_huge_pages de memfd_pin_folios memfd_pin_folios seguido de unpin_folios no puede restaurar free_huge_pages si las p\u00e1ginas no ten\u00edan ya un error, porque el recuento de referencias de folio para las p\u00e1ginas creadas por memfd_alloc_folio nunca llega a 0. memfd_pin_folios necesita otro folio_put para deshacer el folio_try_get a continuaci\u00f3n: memfd_alloc_folio() alloc_hugetlb_folio_nodemask() dequeue_hugetlb_folio_nodemask() dequeue_hugetlb_folio_node_exact() folio_ref_unfreeze(folio, 1); ; agrega 1 recuento de referencias folio_try_get() ; agrega 1 recuento de referencias hugetlb_add_to_page_cache() ; agrega 512 refcount (en x86) Con la soluci\u00f3n, despu\u00e9s de memfd_pin_folios + unpin_folios, el refcount para la p\u00e1gina (sin fallos) es 512, lo cual es correcto, ya que el refcount para una p\u00e1gina sin fijar con fallos es 513."}], "lastModified": "2024-10-23T15:13:25.583", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}