CVE-2024-35791
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.24% probability · 15th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel · debian/debian linux
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/12f8e32a5a389a5d58afc67728c76e61beee1ad4Patch
- https://git.kernel.org/stable/c/2d13b79640b147bd77c34a5998533b2021a4122dPatch
- https://git.kernel.org/stable/c/4868c0ecdb6cfde7c70cf478c46e06bb9c7e5865Patch
- https://git.kernel.org/stable/c/5ef1d8c1ddbf696e47b226e11888eaf8d9e8e807Patch
- https://git.kernel.org/stable/c/e126b508ed2e616d679d85fca2fbe77bb48bbdd7Patch
- https://git.kernel.org/stable/c/f6d53d8a2617dd58c89171a6b9610c470ebda38aPatch
- https://git.kernel.org/stable/c/12f8e32a5a389a5d58afc67728c76e61beee1ad4Patch
- https://git.kernel.org/stable/c/2d13b79640b147bd77c34a5998533b2021a4122dPatch
- https://git.kernel.org/stable/c/4868c0ecdb6cfde7c70cf478c46e06bb9c7e5865Patch
- https://git.kernel.org/stable/c/5ef1d8c1ddbf696e47b226e11888eaf8d9e8e807Patch
- https://git.kernel.org/stable/c/e126b508ed2e616d679d85fca2fbe77bb48bbdd7Patch
- https://git.kernel.org/stable/c/f6d53d8a2617dd58c89171a6b9610c470ebda38aPatch
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.htmlThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.