kvm: Fix nonsense handling of compat ioctl

KVM_SET_SIGNAL_MASK passed a NULL argument leaves the on stack signal
sets uninitialized. It then passes them through to
kvm_vcpu_ioctl_set_sigmask.

We should be passing a NULL in this case not translated garbage.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2468523..d617f69 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1976,9 +1976,10 @@ static long kvm_vcpu_compat_ioctl(struct file *filp,
                        if (copy_from_user(&csigset, sigmask_arg->sigset,
                                           sizeof csigset))
                                goto out;
-               }
-               sigset_from_compat(&sigset, &csigset);
-               r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
+                       sigset_from_compat(&sigset, &csigset);
+                       r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
+               } else
+                       r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL);
                break;
        }
        default: