CVE-2022-49562

{"id": "CVE-2022-49562", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2025-02-26T07:01:31.970", "references": [{"url": "https://git.kernel.org/stable/c/38b888911e8dc89b89d8147cfb1d2dbe6373bf78", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8089e5e1d18402fb8152d6b6815450a36fffa9b0", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f122dfe4476890d60b8c679128cd2259ec96a24c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits\n\nUse the recently introduced __try_cmpxchg_user() to update guest PTE A/D\nbits instead of mapping the PTE into kernel address space. The VM_PFNMAP\npath is broken as it assumes that vm_pgoff is the base pfn of the mapped\nVMA range, which is conceptually wrong as vm_pgoff is the offset relative\nto the file and has nothing to do with the pfn. The horrific hack worked\nfor the original use case (backing guest memory with /dev/mem), but leads\nto accessing \"random\" pfns for pretty much any other VM_PFNMAP case."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: KVM: x86: Use __try_cmpxchg_user() para actualizar los bits A/D de la PTE invitada Use la recientemente introducida __try_cmpxchg_user() para actualizar los bits A/D de la PTE invitada en lugar de mapear la PTE en el espacio de direcciones del kernel. La ruta VM_PFNMAP est\u00e1 rota ya que asume que vm_pgoff es la pfn base del rango VMA mapeado, lo cual es conceptualmente incorrecto ya que vm_pgoff es el desplazamiento relativo al archivo y no tiene nada que ver con la pfn. El horrible hack funcion\u00f3 para el caso de uso original (respaldar la memoria invitada con /dev/mem), pero conduce al acceso a pfn \"aleatorios\" para pr\u00e1cticamente cualquier otro caso VM_PFNMAP."}], "lastModified": "2025-10-22T19:10:00.477", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "036CD419-598A-4414-8106-19AC0696AAF2", "versionEndExcluding": "5.17.13", "versionStartIncluding": "5.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "9FF255A1-64F4-4E31-AF44-C92FB8773BA2", "versionEndExcluding": "5.18.2", "versionStartIncluding": "5.18"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}