fkie_cve-2021-47450
Vulnerability from fkie_nvd
Published
2024-05-22 07:15
Modified
2024-11-21 06:36
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix host stage-2 PGD refcount The KVM page-table library refcounts the pages of concatenated stage-2 PGDs individually. However, when running KVM in protected mode, the host's stage-2 PGD is currently managed by EL2 as a single high-order compound page, which can cause the refcount of the tail pages to reach 0 when they shouldn't, hence corrupting the page-table. Fix this by introducing a new hyp_split_page() helper in the EL2 page allocator (matching the kernel's split_page() function), and make use of it from host_s2_zalloc_pages_exact().
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1d58a17ef54599506d44c45ac95be27273a4d2b1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b372264c66ef78f2cab44e877fbd765ad6d24c39
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/1d58a17ef54599506d44c45ac95be27273a4d2b1
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/b372264c66ef78f2cab44e877fbd765ad6d24c39
Impacted products
Vendor Product Version


To clipboard 

{
   cveTags: [],
   descriptions: [
      {
         lang: "en",
         value: "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix host stage-2 PGD refcount\n\nThe KVM page-table library refcounts the pages of concatenated stage-2\nPGDs individually. However, when running KVM in protected mode, the\nhost's stage-2 PGD is currently managed by EL2 as a single high-order\ncompound page, which can cause the refcount of the tail pages to reach 0\nwhen they shouldn't, hence corrupting the page-table.\n\nFix this by introducing a new hyp_split_page() helper in the EL2 page\nallocator (matching the kernel's split_page() function), and make use of\nit from host_s2_zalloc_pages_exact().",
      },
      {
         lang: "es",
         value: "En el kernel de Linux, se resolvió la siguiente vulnerabilidad: KVM: arm64: corrige el recuento de PGD de etapa 2 del host La librería de tablas de páginas de KVM vuelve a contar las páginas de los PGD de etapa 2 concatenados individualmente. Sin embargo, cuando se ejecuta KVM en modo protegido, EL2 administra actualmente el PGD de etapa 2 del host como una única página compuesta de alto orden, lo que puede causar que el recuento de las páginas finales llegue a 0 cuando no debería, corrompiendo así el tabla de páginas. Solucione este problema introduciendo un nuevo asistente hyp_split_page() en el asignador de páginas EL2 (que coincida con la función split_page() del kernel) y utilícelo desde host_s2_zalloc_pages_exact().",
      },
   ],
   id: "CVE-2021-47450",
   lastModified: "2024-11-21T06:36:10.327",
   metrics: {},
   published: "2024-05-22T07:15:10.143",
   references: [
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/1d58a17ef54599506d44c45ac95be27273a4d2b1",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/b372264c66ef78f2cab44e877fbd765ad6d24c39",
      },
      {
         source: "af854a3a-2127-422b-91ae-364da2661108",
         url: "https://git.kernel.org/stable/c/1d58a17ef54599506d44c45ac95be27273a4d2b1",
      },
      {
         source: "af854a3a-2127-422b-91ae-364da2661108",
         url: "https://git.kernel.org/stable/c/b372264c66ef78f2cab44e877fbd765ad6d24c39",
      },
   ],
   sourceIdentifier: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
   vulnStatus: "Awaiting Analysis",
}


Log in or create an account to share your comment.

Security Advisory comment format.

This schema specifies the format of a comment related to a security advisory.

UUIDv4 of the comment
UUIDv4 of the Vulnerability-Lookup instance
When the comment was created originally
When the comment was last updated
Title of the comment
Description of the comment
The identifier of the vulnerability (CVE ID, GHSA-ID, PYSEC ID, etc.).



Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.