KVM: x86: Protect DR-based index computations from Spectre-v1/L1TF attacks
commit ea740059ecb37807ba47b84b33d1447435a8d868 upstream.
This fixes a Spectre-v1/L1TF vulnerability in __kvm_set_dr() and
kvm_get_dr().
Both kvm_get_dr() and kvm_set_dr() (a wrapper of __kvm_set_dr()) are
exported symbols so KVM should tream them conservatively from a security
perspective.
Fixes: 020df0794f
("KVM: move DR register access handling into generic code")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
eef3ed3f9f
commit
db155131e3
1 changed files with 6 additions and 2 deletions
|
@ -961,9 +961,11 @@ static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu)
|
|||
|
||||
static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
|
||||
{
|
||||
size_t size = ARRAY_SIZE(vcpu->arch.db);
|
||||
|
||||
switch (dr) {
|
||||
case 0 ... 3:
|
||||
vcpu->arch.db[dr] = val;
|
||||
vcpu->arch.db[array_index_nospec(dr, size)] = val;
|
||||
if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
|
||||
vcpu->arch.eff_db[dr] = val;
|
||||
break;
|
||||
|
@ -1000,9 +1002,11 @@ EXPORT_SYMBOL_GPL(kvm_set_dr);
|
|||
|
||||
int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
|
||||
{
|
||||
size_t size = ARRAY_SIZE(vcpu->arch.db);
|
||||
|
||||
switch (dr) {
|
||||
case 0 ... 3:
|
||||
*val = vcpu->arch.db[dr];
|
||||
*val = vcpu->arch.db[array_index_nospec(dr, size)];
|
||||
break;
|
||||
case 4:
|
||||
/* fall through */
|
||||
|
|
Loading…
Reference in a new issue