From: Peter Xu <peterx@xxxxxxxxxx> commit 4ddc9204572c33f2eb91fbdb1d99d8078388b67d upstream. kvm_dirty_bitmap_bytes() will return the size of the dirty bitmap of the memslot rather than the size of bitmap passed over from the ioctl. Here for KVM_CLEAR_DIRTY_LOG we should only copy exactly the size of bitmap that covers kvm_clear_dirty_log.num_pages. Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Fixes: 2a31b9db153530df4aa02dac8c32837bf5f47019 Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- virt/kvm/kvm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1251,7 +1251,7 @@ int kvm_clear_dirty_log_protect(struct k if (!dirty_bitmap) return -ENOENT; - n = kvm_dirty_bitmap_bytes(memslot); + n = ALIGN(log->num_pages, BITS_PER_LONG) / 8; if (log->first_page > memslot->npages || log->num_pages > memslot->npages - log->first_page)