2026-04-01 08:36:33
Linux
PUBLISHED
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Only WARN in direct MMUs when overwriting shadow-present SPTE
Adjust KVMs sanity check against overwriting a shadow-present SPTE with a
another SPTE with a different target PFN to only apply to direct MMUs,
i.e. only to MMUs without shadowed gPTEs. While its impossible for KVM
to overwrite a shadow-present SPTE in response to a guest write, writes
from outside the scope of KVM, e.g. from host userspace, arent detected
by KVMs write tracking and so can break KVMs shadow paging rules.
------------[ cut here ]------------
pfn != spte_to_pfn(*sptep)
WARNING: arch/x86/kvm/mmu/mmu.c:3069 at mmu_set_spte+0x1e4/0x440 [kvm], CPU#0: vmx_ept_stale_r/872
Modules linked in: kvm_intel kvm irqbypass
CPU: 0 UID: 1000 PID: 872 Comm: vmx_ept_stale_r Not tainted 7.0.0-rc2-eafebd2d2ab0-sink-vm #319 PREEMPT
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:mmu_set_spte+0x1e4/0x440 [kvm]
Call Trace: