Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 38/38] KVM: s390: prevent buffer overrun on memory hotplug during migration | Date | Mon, 8 Jan 2018 13:59:31 +0100 |
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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);
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