From 49a2686adddebe1ae76b4d368383208656ef6606 Mon Sep 17 00:00:00 2001 From: Claudio Imbrenda Date: Wed, 5 Jul 2023 13:19:37 +0200 Subject: [PATCH] KVM: s390: pv: fix index value of replaced ASCE MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ 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 Fixes: faa2f72cb356 ("KVM: s390: pv: leak the topmost page table when destroy fails") Reviewed-by: Janosch Frank Signed-off-by: Claudio Imbrenda Message-ID: <20230705111937.33472-3-imbrenda@linux.ibm.com> Signed-off-by: Sasha Levin --- 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 ff40bf92db43..a2c872de29a6 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));