From: Yosry Ahmed <yosry@kernel.org> stable inclusion from stable-v6.12.110 commit d03e721801ac54b9fdf05668aa0c069f07913b68 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19276 CVE: CVE-2026-89929 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 6d00e67326d831e6e610933a3800712f4ffe6ec1 upstream. When emulating INVVPID, KVM executes INVVPID on the physical CPU using vpid02 (instead of the L1 assigned VPID), after doing some validations on the operands. However, it is possible that the physical CPU KVM executes INVVPID on is different from the CPU L2 is running on. For example, in the following scenario: - L2 runs on CPU #1 and exits to L1 (vmx->nested.vmcs02.cpu=1) - L1 migrates to CPU #2 and executes INVVPID - KVM executes INVVPID on CPU #2 - L1 migrates back to CPU #1 and runs L2 (vmx->nested.vmcs02.cpu=1) The TLB entries on CPU #1 are never invalidated, because INVVPID was executed on CPU #2, and vmcs02 never ran on a different pCPU (i.e. vmx_vcpu_load_vmcs() will *not* request KVM_REQ_TLB_FLUSH). Ensure that INVVPID is being executed on the same pCPU that L2 last ran on, and if not, fallback to clearing last_vpid=0 to trigger a full VPID flush on the next nested VM-Enter (as KVM will detect L1 using a different VPID for L2). If L2 ends up running on a different pCPU, KVM will flush the TLB anyway through vmx_vcpu_load_vmcs(). Cc: stable@vger.kernel.org Signed-off-by: Yosry Ahmed <yosry@kernel.org> Reviewed-by: Kai Huang <kai.huang@intel.com> Link: https://patch.msgid.link/20260616214652.2157032-4-yosry@kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zhang Kunbo <zhangkunbo@huawei.com> --- arch/x86/kvm/vmx/nested.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 87f8e0231f28..9f720a6f3444 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5890,6 +5890,7 @@ static int handle_invvpid(struct kvm_vcpu *vcpu) u64 gla; } operand; int r, gpr_index; + int cpu; if (!(vmx->nested.msrs.secondary_ctls_high & SECONDARY_EXEC_ENABLE_VPID) || @@ -5938,11 +5939,19 @@ static int handle_invvpid(struct kvm_vcpu *vcpu) * and never explicitly flush vpid01. INVVPID targets a VPID, not a * VMCS, and so whether or not the current vmcs12 has VPID enabled is * irrelevant (and there may not be a loaded vmcs12). + * + * If vmcs02 was last loaded on a different pCPU, then defer the flush + * by invalidating the nested VPID tracking to ensure that KVM performs + * the invalidation on the correct pCPU. */ - if (type == VMX_VPID_EXTENT_INDIVIDUAL_ADDR) + cpu = get_cpu(); + if (cpu != vmx->nested.vmcs02.cpu) + vmx->nested.last_vpid = 0; + else if (type == VMX_VPID_EXTENT_INDIVIDUAL_ADDR) vpid_sync_vcpu_addr(nested_get_vpid02(vcpu), operand.gla); else vpid_sync_context(nested_get_vpid02(vcpu)); + put_cpu(); /* * Sync the shadow page tables if EPT is disabled, L1 is invalidating -- 2.34.1