diff options
| author | Alexey Kardashevskiy | 2022-06-01 03:43:28 +0200 |
|---|---|---|
| committer | Paolo Bonzini | 2022-06-07 11:18:59 -0400 |
| commit | e8bc2427018826e02add7b0ed0fc625a60390ae5 (patch) | |
| tree | 52661a1814da48f885f74fe2db8696b43144657a /virt | |
| parent | ffd1925a596ce68bed7d81c61cb64bc35f788a9d (diff) | |
KVM: Don't null dereference ops->destroy
A KVM device cleanup happens in either of two callbacks:
1) destroy() which is called when the VM is being destroyed;
2) release() which is called when a device fd is closed.
Most KVM devices use 1) but Book3s's interrupt controller KVM devices
(XICS, XIVE, XIVE-native) use 2) as they need to close and reopen during
the machine execution. The error handling in kvm_ioctl_create_device()
assumes destroy() is always defined which leads to NULL dereference as
discovered by Syzkaller.
This adds a checks for destroy!=NULL and adds a missing release().
This is not changing kvm_destroy_devices() as devices with defined
release() should have been removed from the KVM devices list by then.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 342043b30125..f2922ba3b7a8 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4300,8 +4300,11 @@ static int kvm_ioctl_create_device(struct kvm *kvm, kvm_put_kvm_no_destroy(kvm); mutex_lock(&kvm->lock); list_del(&dev->vm_node); + if (ops->release) + ops->release(dev); mutex_unlock(&kvm->lock); - ops->destroy(dev); + if (ops->destroy) + ops->destroy(dev); return ret; } |