diff mbox

[3/4] KVM: Don't destroy vcpu in case vcpu_setup fails

Message ID 1340987524-22261-4-git-send-email-herton.krzesinski@canonical.com
State New
Headers show

Commit Message

Herton Ronaldo Krzesinski June 29, 2012, 4:32 p.m. UTC 
From: Glauber Costa <glommer@redhat.com>

CVE-2012-1601

BugLink: http://bugs.launchpad.net/bugs/971685

One of vcpu_setup responsibilities is to do mmu initialization.
However, in case we fail in kvm_arch_vcpu_reset, before we get the
chance to init mmu. OTOH, vcpu_destroy will attempt to destroy mmu,
triggering a bug. Keeping track of whether or not mmu is initialized
would unnecessarily complicate things. Rather, we just make return,
making sure any needed uninitialization is done before we return, in
case we fail.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
(cherry picked from commit 7d8fece678c1abc2ca3e1ceda2277c3538a9161c upstream)
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
---
 .../binary-custom.d/openvz/src/virt/kvm/kvm_main.c |    5 ++---
 debian/binary-custom.d/xen/src/virt/kvm/kvm_main.c |    5 ++---
 virt/kvm/kvm_main.c                                |    5 ++---
 3 files changed, 6 insertions(+), 9 deletions(-)
diff mbox

Patch

diff --git a/debian/binary-custom.d/openvz/src/virt/kvm/kvm_main.c b/debian/binary-custom.d/openvz/src/virt/kvm/kvm_main.c
index a1794b6..07adef4 100644
--- a/debian/binary-custom.d/openvz/src/virt/kvm/kvm_main.c
+++ b/debian/binary-custom.d/openvz/src/virt/kvm/kvm_main.c
@@ -799,12 +799,11 @@  static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 
 	r = kvm_arch_vcpu_setup(vcpu);
 	if (r)
-		goto vcpu_destroy;
+		return r;
 
 	mutex_lock(&kvm->lock);
 	if (kvm->vcpus[n]) {
 		r = -EEXIST;
-		mutex_unlock(&kvm->lock);
 		goto vcpu_destroy;
 	}
 	kvm->vcpus[n] = vcpu;
@@ -819,8 +818,8 @@  static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 unlink:
 	mutex_lock(&kvm->lock);
 	kvm->vcpus[n] = NULL;
-	mutex_unlock(&kvm->lock);
 vcpu_destroy:
+	mutex_unlock(&kvm->lock);
 	kvm_arch_vcpu_destroy(vcpu);
 	return r;
 }
diff --git a/debian/binary-custom.d/xen/src/virt/kvm/kvm_main.c b/debian/binary-custom.d/xen/src/virt/kvm/kvm_main.c
index a1794b6..07adef4 100644
--- a/debian/binary-custom.d/xen/src/virt/kvm/kvm_main.c
+++ b/debian/binary-custom.d/xen/src/virt/kvm/kvm_main.c
@@ -799,12 +799,11 @@  static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 
 	r = kvm_arch_vcpu_setup(vcpu);
 	if (r)
-		goto vcpu_destroy;
+		return r;
 
 	mutex_lock(&kvm->lock);
 	if (kvm->vcpus[n]) {
 		r = -EEXIST;
-		mutex_unlock(&kvm->lock);
 		goto vcpu_destroy;
 	}
 	kvm->vcpus[n] = vcpu;
@@ -819,8 +818,8 @@  static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 unlink:
 	mutex_lock(&kvm->lock);
 	kvm->vcpus[n] = NULL;
-	mutex_unlock(&kvm->lock);
 vcpu_destroy:
+	mutex_unlock(&kvm->lock);
 	kvm_arch_vcpu_destroy(vcpu);
 	return r;
 }
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index a1794b6..07adef4 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -799,12 +799,11 @@  static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 
 	r = kvm_arch_vcpu_setup(vcpu);
 	if (r)
-		goto vcpu_destroy;
+		return r;
 
 	mutex_lock(&kvm->lock);
 	if (kvm->vcpus[n]) {
 		r = -EEXIST;
-		mutex_unlock(&kvm->lock);
 		goto vcpu_destroy;
 	}
 	kvm->vcpus[n] = vcpu;
@@ -819,8 +818,8 @@  static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 unlink:
 	mutex_lock(&kvm->lock);
 	kvm->vcpus[n] = NULL;
-	mutex_unlock(&kvm->lock);
 vcpu_destroy:
+	mutex_unlock(&kvm->lock);
 	kvm_arch_vcpu_destroy(vcpu);
 	return r;
 }