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authorLinus Torvalds <torvalds@linux-foundation.org>2013-12-13 00:46:06 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2013-12-13 00:46:06 +0100
commit54fb723cc48db2fde964fb9bb0eaaccf2cf31a9f (patch)
tree71a21d846cd6fe301f1077c98cdf6dfff58048d2 /arch
parentMerge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/... (diff)
parentKVM: x86: fix guest-initiated crash with x2apic (CVE-2013-6376) (diff)
downloadlinux-54fb723cc48db2fde964fb9bb0eaaccf2cf31a9f.tar.xz
linux-54fb723cc48db2fde964fb9bb0eaaccf2cf31a9f.zip
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini: "Four security fixes for KVM on x86. Thanks to Andrew Honig and Lars Bull from Google for reporting them" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: fix guest-initiated crash with x2apic (CVE-2013-6376) KVM: x86: Convert vapic synchronization to _cached functions (CVE-2013-6368) KVM: x86: Fix potential divide by 0 in lapic (CVE-2013-6367) KVM: Improve create VCPU parameter (CVE-2013-4587)
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/lapic.c35
-rw-r--r--arch/x86/kvm/lapic.h4
-rw-r--r--arch/x86/kvm/x86.c40
3 files changed, 24 insertions, 55 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 5439117d5c4c..dec48bfaddb8 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -143,6 +143,8 @@ static inline int kvm_apic_id(struct kvm_lapic *apic)
return (kvm_apic_get_reg(apic, APIC_ID) >> 24) & 0xff;
}
+#define KVM_X2APIC_CID_BITS 0
+
static void recalculate_apic_map(struct kvm *kvm)
{
struct kvm_apic_map *new, *old = NULL;
@@ -180,7 +182,8 @@ static void recalculate_apic_map(struct kvm *kvm)
if (apic_x2apic_mode(apic)) {
new->ldr_bits = 32;
new->cid_shift = 16;
- new->cid_mask = new->lid_mask = 0xffff;
+ new->cid_mask = (1 << KVM_X2APIC_CID_BITS) - 1;
+ new->lid_mask = 0xffff;
} else if (kvm_apic_sw_enabled(apic) &&
!new->cid_mask /* flat mode */ &&
kvm_apic_get_reg(apic, APIC_DFR) == APIC_DFR_CLUSTER) {
@@ -841,7 +844,8 @@ static u32 apic_get_tmcct(struct kvm_lapic *apic)
ASSERT(apic != NULL);
/* if initial count is 0, current count should also be 0 */
- if (kvm_apic_get_reg(apic, APIC_TMICT) == 0)
+ if (kvm_apic_get_reg(apic, APIC_TMICT) == 0 ||
+ apic->lapic_timer.period == 0)
return 0;
remaining = hrtimer_get_remaining(&apic->lapic_timer.timer);
@@ -1691,7 +1695,6 @@ static void apic_sync_pv_eoi_from_guest(struct kvm_vcpu *vcpu,
void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu)
{
u32 data;
- void *vapic;
if (test_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention))
apic_sync_pv_eoi_from_guest(vcpu, vcpu->arch.apic);
@@ -1699,9 +1702,8 @@ void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu)
if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention))
return;
- vapic = kmap_atomic(vcpu->arch.apic->vapic_page);
- data = *(u32 *)(vapic + offset_in_page(vcpu->arch.apic->vapic_addr));
- kunmap_atomic(vapic);
+ kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.apic->vapic_cache, &data,
+ sizeof(u32));
apic_set_tpr(vcpu->arch.apic, data & 0xff);
}
@@ -1737,7 +1739,6 @@ void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu)
u32 data, tpr;
int max_irr, max_isr;
struct kvm_lapic *apic = vcpu->arch.apic;
- void *vapic;
apic_sync_pv_eoi_to_guest(vcpu, apic);
@@ -1753,18 +1754,24 @@ void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu)
max_isr = 0;
data = (tpr & 0xff) | ((max_isr & 0xf0) << 8) | (max_irr << 24);
- vapic = kmap_atomic(vcpu->arch.apic->vapic_page);
- *(u32 *)(vapic + offset_in_page(vcpu->arch.apic->vapic_addr)) = data;
- kunmap_atomic(vapic);
+ kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apic->vapic_cache, &data,
+ sizeof(u32));
}
-void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)
+int kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)
{
- vcpu->arch.apic->vapic_addr = vapic_addr;
- if (vapic_addr)
+ if (vapic_addr) {
+ if (kvm_gfn_to_hva_cache_init(vcpu->kvm,
+ &vcpu->arch.apic->vapic_cache,
+ vapic_addr, sizeof(u32)))
+ return -EINVAL;
__set_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention);
- else
+ } else {
__clear_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention);
+ }
+
+ vcpu->arch.apic->vapic_addr = vapic_addr;
+ return 0;
}
int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data)
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index c730ac9fe801..c8b0d0d2da5c 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -34,7 +34,7 @@ struct kvm_lapic {
*/
void *regs;
gpa_t vapic_addr;
- struct page *vapic_page;
+ struct gfn_to_hva_cache vapic_cache;
unsigned long pending_events;
unsigned int sipi_vector;
};
@@ -76,7 +76,7 @@ void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data);
void kvm_apic_write_nodecode(struct kvm_vcpu *vcpu, u32 offset);
void kvm_apic_set_eoi_accelerated(struct kvm_vcpu *vcpu, int vector);
-void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr);
+int kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr);
void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu);
void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 21ef1ba184ae..5d004da1e35d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3214,8 +3214,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
r = -EFAULT;
if (copy_from_user(&va, argp, sizeof va))
goto out;
- r = 0;
- kvm_lapic_set_vapic_addr(vcpu, va.vapic_addr);
+ r = kvm_lapic_set_vapic_addr(vcpu, va.vapic_addr);
break;
}
case KVM_X86_SETUP_MCE: {
@@ -5739,36 +5738,6 @@ static void post_kvm_run_save(struct kvm_vcpu *vcpu)
!kvm_event_needs_reinjection(vcpu);
}
-static int vapic_enter(struct kvm_vcpu *vcpu)
-{
- struct kvm_lapic *apic = vcpu->arch.apic;
- struct page *page;
-
- if (!apic || !apic->vapic_addr)
- return 0;
-
- page = gfn_to_page(vcpu->kvm, apic->vapic_addr >> PAGE_SHIFT);
- if (is_error_page(page))
- return -EFAULT;
-
- vcpu->arch.apic->vapic_page = page;
- return 0;
-}
-
-static void vapic_exit(struct kvm_vcpu *vcpu)
-{
- struct kvm_lapic *apic = vcpu->arch.apic;
- int idx;
-
- if (!apic || !apic->vapic_addr)
- return;
-
- idx = srcu_read_lock(&vcpu->kvm->srcu);
- kvm_release_page_dirty(apic->vapic_page);
- mark_page_dirty(vcpu->kvm, apic->vapic_addr >> PAGE_SHIFT);
- srcu_read_unlock(&vcpu->kvm->srcu, idx);
-}
-
static void update_cr8_intercept(struct kvm_vcpu *vcpu)
{
int max_irr, tpr;
@@ -6069,11 +6038,6 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
struct kvm *kvm = vcpu->kvm;
vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
- r = vapic_enter(vcpu);
- if (r) {
- srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
- return r;
- }
r = 1;
while (r > 0) {
@@ -6132,8 +6096,6 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
- vapic_exit(vcpu);
-
return r;
}