This is a note to let you know that I've just added the patch titled
KVM: s390: pv: fix index value of replaced ASCE
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-s390-pv-fix-index-value-of-replaced-asce.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f243e46c25a857cb3a9d4d9f440f2ef085cbaa18
Author: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Date: Wed Jul 5 13:19:37 2023 +0200
KVM: s390: pv: fix index value of replaced ASCE
[ Upstream commit c2fceb59bbda16468bda82b002383bff59de89ab ]
The index field of the struct page corresponding to a guest ASCE should
be 0. When replacing the ASCE in s390_replace_asce(), the index of the
new ASCE should also be set to 0.
Having the wrong index might lead to the wrong addresses being passed
around when notifying pte invalidations, and eventually to validity
intercepts (VM crash) if the prefix gets unmapped and the notifier gets
called with the wrong address.
Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
Fixes: faa2f72cb356 ("KVM: s390: pv: leak the topmost page table when destroy fails")
Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Message-ID: <20230705111937.33472-3-imbrenda@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index dc90d1eb0d554..d7e8297d5642b 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2846,6 +2846,7 @@ int s390_replace_asce(struct gmap *gmap)
page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
if (!page)
return -ENOMEM;
+ page->index = 0;
table = page_to_virt(page);
memcpy(table, gmap->table, 1UL << (CRST_ALLOC_ORDER + PAGE_SHIFT));
