]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
KVM: Don't null dereference ops->destroy
authorAlexey Kardashevskiy <aik@ozlabs.ru>
Wed, 1 Jun 2022 01:43:28 +0000 (03:43 +0200)
committerPaolo Bonzini <pbonzini@redhat.com>
Tue, 7 Jun 2022 15:18:59 +0000 (11:18 -0400)
commite8bc2427018826e02add7b0ed0fc625a60390ae5
tree52661a1814da48f885f74fe2db8696b43144657a
parentffd1925a596ce68bed7d81c61cb64bc35f788a9d
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>
virt/kvm/kvm_main.c