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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
4f627ecde7329e476a077bb0590db8f27bb8f912 to < 2d13b79640b147bd77c34a5998533b2021a4122daffected19a23da53932bc8011220bd8c410cb76012de004 to < e126b508ed2e616d679d85fca2fbe77bb48bbdd7affected19a23da53932bc8011220bd8c410cb76012de004 to < 4868c0ecdb6cfde7c70cf478c46e06bb9c7e5865affected19a23da53932bc8011220bd8c410cb76012de004 to < 12f8e32a5a389a5d58afc67728c76e61beee1ad4affected19a23da53932bc8011220bd8c410cb76012de004 to < f6d53d8a2617dd58c89171a6b9610c470ebda38aaffected19a23da53932bc8011220bd8c410cb76012de004 to < 5ef1d8c1ddbf696e47b226e11888eaf8d9e8e807affectedf1ecde00ce1694597f923f0d25f7a797c5243d99affected848bcb0a1d96f67d075465667d3a1ad4af56311eaffected5.10.15 to < 5.10.215affected4.19.176 to < 4.20affected5.4.98 to < 5.5affected
Linux Linux
Default version status: affected
5.11affected0 to < 5.11unaffected5.10.215 to ≤ 5.10.*unaffected5.15.154 to ≤ 5.15.*unaffected6.1.84 to ≤ 6.1.*unaffected6.6.24 to ≤ 6.6.*unaffected6.7.12 to ≤ 6.7.*unaffected6.8 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/2d13b79640b147bd77c34a5998533b2021a4122d ↗
- https://git.kernel.org/stable/c/e126b508ed2e616d679d85fca2fbe77bb48bbdd7 ↗
- https://git.kernel.org/stable/c/4868c0ecdb6cfde7c70cf478c46e06bb9c7e5865 ↗
- https://git.kernel.org/stable/c/12f8e32a5a389a5d58afc67728c76e61beee1ad4 ↗
- https://git.kernel.org/stable/c/f6d53d8a2617dd58c89171a6b9610c470ebda38a ↗
- https://git.kernel.org/stable/c/5ef1d8c1ddbf696e47b226e11888eaf8d9e8e807 ↗
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html ↗