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authorChristian Borntraeger <borntraeger@de.ibm.com>2017-12-21 09:18:22 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-01-10 09:31:23 +0100
commit77bbeea7811f0857952d3f096438ce2e1bb16f1a (patch)
treedd1bb956269a08b166754d4b0c204e7b4c8c5eb4
parent853bcadeefe18ee0661a302811a17644b1f9e80b (diff)
KVM: s390: prevent buffer overrun on memory hotplug during migration
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>
-rw-r--r--arch/s390/kvm/priv.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 5b25287f449b..7bd3a59232f0 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -1009,7 +1009,7 @@ static inline int do_essa(struct kvm_vcpu *vcpu, const int orc)
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);