KVM: fix the handling of dirty bitmaps to avoid overflows

[safe/jmp/linux-2.6] / arch / x86 / kvm / x86.c

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9ad3d06..45aa90f 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2612,8 +2612,9 @@ static int kvm_vm_ioctl_reinject(struct kvm *kvm,
 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
                                      struct kvm_dirty_log *log)
 {
-       int r, n, i;
+       int r, i;
        struct kvm_memory_slot *memslot;
+       unsigned long n;
        unsigned long is_dirty = 0;
        unsigned long *dirty_bitmap = NULL;
 
@@ -2628,7 +2629,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
        if (!memslot->dirty_bitmap)
                goto out;
 
-       n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
+       n = kvm_dirty_bitmap_bytes(memslot);
 
        r = -ENOMEM;
        dirty_bitmap = vmalloc(n);