There are 2 places calling kvm_device_ops::destroy():
1) when creating a KVM device failed;
2) when a VM is destroyed: kvm_destroy_devices() destroys all devices
from &kvm->devices.
All 3 Book3s's interrupt controller KVM devices (XICS, XIVE, XIVE-native)
do not define kvm_device_ops::destroy() and only define release() which
is normally fine as device fds are closed before KVM gets to 2) but
by then the &kvm->devices list is empty.
However Syzkaller manages to trigger 1).
This adds checks in 1) and 2).
Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
---
I could define empty handlers for XICS/XIVE guys but
kvm_ioctl_create_device() already checks for ops->init() so I guess
kvm_device_ops are expected to not have certain handlers.
---
virt/kvm/kvm_main.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f30bb8c16f26..17f698ccddd1 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1205,7 +1205,8 @@ static void kvm_destroy_devices(struct kvm *kvm)
*/
list_for_each_entry_safe(dev, tmp, &kvm->devices, vm_node) {
list_del(&dev->vm_node);
- dev->ops->destroy(dev);
+ if (dev->ops->destroy)
+ dev->ops->destroy(dev);
}
}
@@ -4300,7 +4301,8 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
mutex_lock(&kvm->lock);
list_del(&dev->vm_node);
mutex_unlock(&kvm->lock);
- ops->destroy(dev);
+ if (ops->destroy)
+ ops->destroy(dev);
return ret;
}
--
2.30.2
