diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-12-13 00:46:06 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-12-13 00:46:06 +0100 |
commit | 54fb723cc48db2fde964fb9bb0eaaccf2cf31a9f (patch) | |
tree | 71a21d846cd6fe301f1077c98cdf6dfff58048d2 /arch | |
parent | Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/... (diff) | |
parent | KVM: x86: fix guest-initiated crash with x2apic (CVE-2013-6376) (diff) | |
download | linux-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.c | 35 | ||||
-rw-r--r-- | arch/x86/kvm/lapic.h | 4 | ||||
-rw-r--r-- | arch/x86/kvm/x86.c | 40 |
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; } |