diff options
| author | Ido Yariv <ido@wizery.com> | 2016-10-21 19:39:57 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-02-23 06:50:57 +0300 |
| commit | 56d95c049be3063654f8d184e069edce371728f4 (patch) | |
| tree | d3fdea666cd8988324565cdd53119cc4568976d3 /arch/x86/kvm | |
| parent | 56f3b449b5961a63b0c03bea225209ef00c3c666 (diff) | |
| download | linux-56d95c049be3063654f8d184e069edce371728f4.tar.xz | |
KVM: x86: fix wbinvd_dirty_mask use-after-free
commit bd768e146624cbec7122ed15dead8daa137d909d upstream.
vcpu->arch.wbinvd_dirty_mask may still be used after freeing it,
corrupting memory. For example, the following call trace may set a bit
in an already freed cpu mask:
kvm_arch_vcpu_load
vcpu_load
vmx_free_vcpu_nested
vmx_free_vcpu
kvm_arch_vcpu_free
Fix this by deferring freeing of wbinvd_dirty_mask.
Signed-off-by: Ido Yariv <ido@wizery.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/x86.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 4ae334a1bd99..fc73c12d488b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6406,11 +6406,13 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu) { + void *wbinvd_dirty_mask = vcpu->arch.wbinvd_dirty_mask; + kvmclock_reset(vcpu); - free_cpumask_var(vcpu->arch.wbinvd_dirty_mask); fx_free(vcpu); kvm_x86_ops->vcpu_free(vcpu); + free_cpumask_var(wbinvd_dirty_mask); } struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, |