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| author | Liran Alon <liran.alon@oracle.com> | 2019-07-15 17:47:44 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-07-15 20:40:58 +0200 |
| commit | 6694e48012826351036fd10fc506ca880023e25f (patch) | |
| tree | bc5d3faa50f4a6df7f454ffa9c2b50c9191e733f /arch | |
| parent | kvm: x86: ioapic and apic debug macros cleanup (diff) | |
| download | linux-6694e48012826351036fd10fc506ca880023e25f.tar.xz linux-6694e48012826351036fd10fc506ca880023e25f.zip | |
KVM: nVMX: Ignore segment base for VMX memory operand when segment not FS or GS
As reported by Maxime at
https://bugzilla.kernel.org/show_bug.cgi?id=204175:
In vmx/nested.c::get_vmx_mem_address(), when the guest runs in long mode,
the base address of the memory operand is computed with a simple:
*ret = s.base + off;
This is incorrect, the base applies only to FS and GS, not to the others.
Because of that, if the guest uses a VMX instruction based on DS and has
a DS.base that is non-zero, KVM wrongfully adds the base to the
resulting address.
Reported-by: Maxime Villard <max@m00nbsd.net>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index bb509c254939..4f23e34f628b 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4194,7 +4194,10 @@ int get_vmx_mem_address(struct kvm_vcpu *vcpu, unsigned long exit_qualification, * mode, e.g. a 32-bit address size can yield a 64-bit virtual * address when using FS/GS with a non-zero base. */ - *ret = s.base + off; + if (seg_reg == VCPU_SREG_FS || seg_reg == VCPU_SREG_GS) + *ret = s.base + off; + else + *ret = off; /* Long mode: #GP(0)/#SS(0) if the memory address is in a * non-canonical form. This is the only check on the memory |