Xen/x86: also check kernel mapping in set_foreign_p2m_mapping()

We should not set up further state if either mapping failed; paying
attention to just the user mapping's status isn't enough.

Also use GNTST_okay instead of implying its value (zero).

This is part of XSA-361.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index ac579c44dd285f1481a25275605388ddefa177d0..b5949e5a83ec8bb3f454bccdbe551c40416e2a8c 100644 (file)
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -712,7 +712,8 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
                unsigned long mfn, pfn;
 
                /* Do not add to override if the map failed. */
-               if (map_ops[i].status)
+               if (map_ops[i].status != GNTST_okay ||
+                   (kmap_ops && kmap_ops[i].status != GNTST_okay))
                        continue;
 
                if (map_ops[i].flags & GNTMAP_contains_pte) {