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.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Debian | 12 | all | linux | < 6.1.85-1 | linux_6.1.85-1_all.deb |
Debian | 11 | all | linux | < 5.10.216-1 | linux_5.10.216-1_all.deb |
Debian | 999 | all | linux | < 6.7.12-1 | linux_6.7.12-1_all.deb |
Debian | 13 | all | linux | < 6.7.12-1 | linux_6.7.12-1_all.deb |