From: Claudio Imbrenda imbrenda@linux.ibm.com
[ 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@linaro.org Fixes: faa2f72cb356 ("KVM: s390: pv: leak the topmost page table when destroy fails") Reviewed-by: Janosch Frank frankja@linux.ibm.com Signed-off-by: Claudio Imbrenda imbrenda@linux.ibm.com Message-ID: 20230705111937.33472-3-imbrenda@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/mm/gmap.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 02d15c8dc92e9..243f673fa6515 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -2843,6 +2843,7 @@ 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));