KVM: PPC: fix information leak to userland

Structure kvm_ppc_pvinfo is copied to userland with flags and
pad fields unitialized.  It leads to leaking of contents of
kernel stack memory.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 2f87a1627f6cff35604f96e8e041cffd9af071ff..38f756f2505389ac5f59eb9ae3921ef72175eea1 100644 (file)
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -617,6 +617,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
        switch (ioctl) {
        case KVM_PPC_GET_PVINFO: {
                struct kvm_ppc_pvinfo pvinfo;
+               memset(&pvinfo, 0, sizeof(pvinfo));
                r = kvm_vm_ioctl_get_pvinfo(&pvinfo);
                if (copy_to_user(argp, &pvinfo, sizeof(pvinfo))) {
                        r = -EFAULT;