xen/arm: don't ignore return errors from set_phys_to_machine

commit 36bf1dfb8b266e089afa9b7b984217f17027bf35 upstream.

set_phys_to_machine can fail due to lack of memory, see the kzalloc call
in arch/arm/xen/p2m.c:__set_phys_to_machine_multi.

Don't ignore the potential return error in set_foreign_p2m_mapping,
returning it to the caller instead.

This is part of XSA-361.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Cc: stable@vger.kernel.org
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
index 0641ba54ab62ae9786cb12ab88b2666b5c783b7a..ce538c51fa3fb645b05d4a3b84d479a01497f33e 100644 (file)
--- a/arch/arm/xen/p2m.c
+++ b/arch/arm/xen/p2m.c
@@ -93,8 +93,10 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
        for (i = 0; i < count; i++) {
                if (map_ops[i].status)
                        continue;
-               set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
-                                   map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT);
+               if (unlikely(!set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
+                                   map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT))) {
+                       return -ENOMEM;
+               }
        }
 
        return 0;