fkie_cve-2024-35791
Vulnerability from fkie_nvd
Published
2024-05-17 13:15
Modified
2024-11-21 09:20
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region()
Do the cache flush of converted pages in svm_register_enc_region() before
dropping kvm->lock to fix use-after-free issues where region and/or its
array of pages could be freed by a different task, e.g. if userspace has
__unregister_enc_region_locked() already queued up for the region.
Note, the "obvious" alternative of using local variables doesn't fully
resolve the bug, as region->pages is also dynamically allocated. I.e. the
region structure itself would be fine, but region->pages could be freed.
Flushing multiple pages under kvm->lock is unfortunate, but the entire
flow is a rare slow path, and the manual flush is only needed on CPUs that
lack coherency for encrypted memory.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Flush pages under kvm-\u003elock to fix UAF in svm_register_enc_region()\n\nDo the cache flush of converted pages in svm_register_enc_region() before\ndropping kvm-\u003elock to fix use-after-free issues where region and/or its\narray of pages could be freed by a different task, e.g. if userspace has\n__unregister_enc_region_locked() already queued up for the region.\n\nNote, the \"obvious\" alternative of using local variables doesn\u0027t fully\nresolve the bug, as region-\u003epages is also dynamically allocated. I.e. the\nregion structure itself would be fine, but region-\u003epages could be freed.\n\nFlushing multiple pages under kvm-\u003elock is unfortunate, but the entire\nflow is a rare slow path, and the manual flush is only needed on CPUs that\nlack coherency for encrypted memory."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: KVM: SVM: Vaciar p\u00e1ginas bajo kvm-\u0026gt;lock para arreglar UAF en svm_register_enc_region() Realice el vaciado de cach\u00e9 de las p\u00e1ginas convertidas en svm_register_enc_region() antes de eliminar kvm-\u0026gt;lock para arreglar el uso -Problemas posteriores a la liberaci\u00f3n en los que la regi\u00f3n y/o su conjunto de p\u00e1ginas podr\u00edan liberarse mediante una tarea diferente, por ejemplo, si el espacio de usuario ya tiene __unregister_enc_region_locked() en cola para la regi\u00f3n. Tenga en cuenta que la alternativa \"obvia\" de usar variables locales no resuelve completamente el error, ya que regi\u00f3n-\u0026gt;p\u00e1ginas tambi\u00e9n se asigna din\u00e1micamente. Es decir, la estructura de la regi\u00f3n en s\u00ed estar\u00eda bien, pero se podr\u00edan liberar regiones-\u0026gt;p\u00e1ginas. Vaciar varias p\u00e1ginas bajo kvm-\u0026gt;lock es desafortunado, pero todo el flujo es un camino lento poco com\u00fan, y el vaciado manual solo es necesario en CPU que carecen de coherencia para la memoria cifrada."
}
],
"id": "CVE-2024-35791",
"lastModified": "2024-11-21T09:20:54.250",
"metrics": {},
"published": "2024-05-17T13:15:58.873",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/12f8e32a5a389a5d58afc67728c76e61beee1ad4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2d13b79640b147bd77c34a5998533b2021a4122d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4868c0ecdb6cfde7c70cf478c46e06bb9c7e5865"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/5ef1d8c1ddbf696e47b226e11888eaf8d9e8e807"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e126b508ed2e616d679d85fca2fbe77bb48bbdd7"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f6d53d8a2617dd58c89171a6b9610c470ebda38a"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/12f8e32a5a389a5d58afc67728c76e61beee1ad4"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/2d13b79640b147bd77c34a5998533b2021a4122d"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/4868c0ecdb6cfde7c70cf478c46e06bb9c7e5865"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/5ef1d8c1ddbf696e47b226e11888eaf8d9e8e807"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/e126b508ed2e616d679d85fca2fbe77bb48bbdd7"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/f6d53d8a2617dd58c89171a6b9610c470ebda38a"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Confirmed: The vulnerability is confirmed from an analyst perspective.
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- 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.