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 5.15-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-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b295b7e4014dd96e83bfd9f8778f82dd01044ef5
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 ff40bf92db43a..a2c872de29a66 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2791,6 +2791,7 @@ 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));
