From 017f686bcb536ff23d49c143fdf9d1fd89a9a924 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=utf8 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 02d15c8..243f673 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)); -- 2.7.4