diff options
| author | Avi Kivity <avi@redhat.com> | 2010-09-17 13:13:18 -0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-09-26 17:18:34 -0700 |
| commit | d963ca2b66d33935a858dc01a899dec0b3c77fc9 (patch) | |
| tree | c2f340079a84fdef22573f1556b0c1562ec04b50 | |
| parent | 291e06417553bbca9d6cf59d5ac1040a9d71da99 (diff) | |
KVM: VMX: Fix host GDT.LIMIT corruption
commit 3444d7da1839b851eefedd372978d8a982316c36 upstream.
vmx does not restore GDT.LIMIT to the host value, instead it sets it to 64KB.
This means host userspace can learn a few bits of host memory.
Fix by reloading GDTR when we load other host state.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index ee03679efe7..7d043883d9b 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -177,6 +177,7 @@ static u64 construct_eptp(unsigned long root_hpa); static DEFINE_PER_CPU(struct vmcs *, vmxarea); static DEFINE_PER_CPU(struct vmcs *, current_vmcs); static DEFINE_PER_CPU(struct list_head, vcpus_on_cpu); +static DEFINE_PER_CPU(struct desc_ptr, host_gdt); static unsigned long *vmx_io_bitmap_a; static unsigned long *vmx_io_bitmap_b; @@ -812,6 +813,7 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx) wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base); } #endif + load_gdt(&__get_cpu_var(host_gdt)); } static void vmx_load_host_state(struct vcpu_vmx *vmx) @@ -1314,6 +1316,8 @@ static int hardware_enable(void *garbage) ept_sync_global(); + store_gdt(&__get_cpu_var(host_gdt)); + return 0; } |