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authorLinus Torvalds <torvalds@linux-foundation.org>2014-04-14 16:21:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-14 16:21:28 -0700
commit55101e2d6ce1c780f6ee8fee5f37306971aac6cd (patch)
tree348adcfd97517ee9b5041f31df15cdd7fedb8ea7 /virt
parentdafe344d2288f0ebc0e3d4c6a5eb15bc82189c53 (diff)
parentb351c39cc9e0151cee9b8d52a1e714928faabb38 (diff)
downloadlwn-55101e2d6ce1c780f6ee8fee5f37306971aac6cd.tar.gz
lwn-55101e2d6ce1c780f6ee8fee5f37306971aac6cd.zip
Merge git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Marcelo Tosatti: - Fix for guest triggerable BUG_ON (CVE-2014-0155) - CR4.SMAP support - Spurious WARN_ON() fix * git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: remove WARN_ON from get_kernel_ns() KVM: Rename variable smep to cr4_smep KVM: expose SMAP feature to guest KVM: Disable SMAP for guests in EPT realmode and EPT unpaging mode KVM: Add SMAP support when setting CR4 KVM: Remove SMAP bit from CR4_RESERVED_BITS KVM: ioapic: try to recover if pending_eoi goes out of range KVM: ioapic: fix assignment of ioapic->rtc_status.pending_eoi (CVE-2014-0155)
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/ioapic.c25
1 files changed, 19 insertions, 6 deletions
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index d4b601547f1f..2458a1dc2ba9 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -97,6 +97,14 @@ static void rtc_irq_eoi_tracking_reset(struct kvm_ioapic *ioapic)
bitmap_zero(ioapic->rtc_status.dest_map, KVM_MAX_VCPUS);
}
+static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic);
+
+static void rtc_status_pending_eoi_check_valid(struct kvm_ioapic *ioapic)
+{
+ if (WARN_ON(ioapic->rtc_status.pending_eoi < 0))
+ kvm_rtc_eoi_tracking_restore_all(ioapic);
+}
+
static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
{
bool new_val, old_val;
@@ -120,9 +128,8 @@ static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
} else {
__clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
ioapic->rtc_status.pending_eoi--;
+ rtc_status_pending_eoi_check_valid(ioapic);
}
-
- WARN_ON(ioapic->rtc_status.pending_eoi < 0);
}
void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
@@ -149,10 +156,10 @@ static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic)
static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu)
{
- if (test_and_clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map))
+ if (test_and_clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map)) {
--ioapic->rtc_status.pending_eoi;
-
- WARN_ON(ioapic->rtc_status.pending_eoi < 0);
+ rtc_status_pending_eoi_check_valid(ioapic);
+ }
}
static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic)
@@ -353,10 +360,16 @@ static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status)
ioapic->irr &= ~(1 << irq);
if (irq == RTC_GSI && line_status) {
+ /*
+ * pending_eoi cannot ever become negative (see
+ * rtc_status_pending_eoi_check_valid) and the caller
+ * ensures that it is only called if it is >= zero, namely
+ * if rtc_irq_check_coalesced returns false).
+ */
BUG_ON(ioapic->rtc_status.pending_eoi != 0);
ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe,
ioapic->rtc_status.dest_map);
- ioapic->rtc_status.pending_eoi = ret;
+ ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret);
} else
ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL);