This is a note to let you know that I've just added the patch titled

KVM: s390: prevent buffer overrun on memory hotplug during migration

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: kvm-s390-prevent-buffer-overrun-on-memory-hotplug-during-migration.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From c2cf265d860882b51a200e4a7553c17827f2b730 Mon Sep 17 00:00:00 2001

From: Christian Borntraeger borntraeger@de.ibm.com Date: Thu, 21 Dec 2017 09:18:22 +0100 Subject: KVM: s390: prevent buffer overrun on memory hotplug during migration

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);

Patches currently in stable-queue which might be from borntraeger@de.ibm.com are

queue-4.14/kvm-s390-prevent-buffer-overrun-on-memory-hotplug-during-migration.patch queue-4.14/kvm-s390-fix-cmma-migration-for-multiple-memory-slots.patch