4.14-stable review patch. If anyone has any objections, please let me know.
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From: Christian Borntraeger borntraeger@de.ibm.com
commit c2cf265d860882b51a200e4a7553c17827f2b730 upstream.
We must not go beyond the pre-allocated buffer. This can happen when a new memory slot is added during migration.
Reported-by: David Hildenbrand david@redhat.com Signed-off-by: Christian Borntraeger borntraeger@de.ibm.com Fixes: 190df4a212a7 (KVM: s390: CMMA tracking, ESSA emulation, migration mode) Reviewed-by: Cornelia Huck cohuck@redhat.com Reviewed-by: David Hildenbrand david@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/s390/kvm/priv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -1009,7 +1009,7 @@ static inline int do_essa(struct kvm_vcp cbrlo[entries] = gfn << PAGE_SHIFT; }
- if (orc) { + if (orc && gfn < ms->bitmap_size) { /* increment only if we are really flipping the bit to 1 */ if (!test_and_set_bit(gfn, ms->pgste_bitmap)) atomic64_inc(&ms->dirty_pages);