CVE-2021-47639

CVE-2021-47639 affects the Linux kernel KVM x86/mmu code. The issue arises when unmapping a guest frame number (gfn) range in the TDP MMU: both valid and invalid SPTE roots can be zapped, but invalid roots aren’t consistently cleared in mmu_notifier paths. This can leave references to freed pages...

CVE-2021-47639 KVM: x86/mmu: Zap _all_ roots when unmapping gfn range in TDP MMU

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Zap all roots when unmapping gfn range in TDP MMU Zap both valid and invalid roots when zapping/unmapping a gfn range, as KVM must ensure it holds no references to the freed page after returning from the unmap...