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| author | Sean Christopherson <seanjc@google.com> | 2024-09-06 06:34:13 +0200 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2024-09-10 05:15:03 +0200 |
| commit | 3dde46a21aa72a3640bf3f6ff5ce7838af06a1f9 (patch) | |
| tree | 52c60212980d73a6b16b3f3e96b6109e5b17c735 /arch/x86 | |
| parent | KVM: nVMX: Explicitly invalidate posted_intr_nv if PI is disabled at VM-Enter (diff) | |
| download | linux-3dde46a21aa72a3640bf3f6ff5ce7838af06a1f9.tar.xz linux-3dde46a21aa72a3640bf3f6ff5ce7838af06a1f9.zip | |
KVM: nVMX: Assert that vcpu->mutex is held when accessing secondary VMCSes
Add lockdep assertions in get_vmcs12() and get_shadow_vmcs12() to verify
the vCPU's mutex is held, as the returned VMCS objects are dynamically
allocated/freed when nested VMX is turned on/off, i.e. accessing vmcs12
structures without holding vcpu->mutex is susceptible to use-after-free.
Waive the assertion if the VM is being destroyed, as KVM currently forces
a nested VM-Exit when freeing the vCPU. If/when that wart is fixed, the
assertion can/should be converted to an unqualified lockdep assertion.
See also https://lore.kernel.org/all/Zsd0TqCeY3B5Sb5b@google.com.
Link: https://lore.kernel.org/r/20240906043413.1049633-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/vmx/nested.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h index cce4e2aa30fb..668b6c83a373 100644 --- a/arch/x86/kvm/vmx/nested.h +++ b/arch/x86/kvm/vmx/nested.h @@ -39,11 +39,17 @@ bool nested_vmx_check_io_bitmaps(struct kvm_vcpu *vcpu, unsigned int port, static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu) { + lockdep_assert_once(lockdep_is_held(&vcpu->mutex) || + !refcount_read(&vcpu->kvm->users_count)); + return to_vmx(vcpu)->nested.cached_vmcs12; } static inline struct vmcs12 *get_shadow_vmcs12(struct kvm_vcpu *vcpu) { + lockdep_assert_once(lockdep_is_held(&vcpu->mutex) || + !refcount_read(&vcpu->kvm->users_count)); + return to_vmx(vcpu)->nested.cached_shadow_vmcs12; } |