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> --- virt/kvm/kvm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 53de2f946f9e..ad39c57de82d 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1251,7 +1251,7 @@ int kvm_clear_dirty_log_protect(struct kvm *kvm, 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 || -- 2.17.1