Merge tag 'for-linus-5.12b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:
 "Two security issues (XSA-367 and XSA-369)"

* tag 'for-linus-5.12b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: fix p2m size in dom0 for disabled memory hotplug case
  xen-netback: respect gnttab_map_refs()'s return value
  Xen/gnttab: handle p2m update errors on a per-slot basis

1 files changed, 31 insertions, 4 deletions

diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
index fd6e3aafe272..acb464547a54 100644
--- a/arch/arm/xen/p2m.c
+++ b/arch/arm/xen/p2m.c
@@ -93,12 +93,39 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
 	int i;
 
 	for (i = 0; i < count; i++) {
+		struct gnttab_unmap_grant_ref unmap;
+		int rc;
+
 		if (map_ops[i].status)
 			continue;
-		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;
-		}
+		if (likely(set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
+				    map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT)))
+			continue;
+
+		/*
+		 * Signal an error for this slot. This in turn requires
+		 * immediate unmapping.
+		 */
+		map_ops[i].status = GNTST_general_error;
+		unmap.host_addr = map_ops[i].host_addr,
+		unmap.handle = map_ops[i].handle;
+		map_ops[i].handle = ~0;
+		if (map_ops[i].flags & GNTMAP_device_map)
+			unmap.dev_bus_addr = map_ops[i].dev_bus_addr;
+		else
+			unmap.dev_bus_addr = 0;
+
+		/*
+		 * Pre-populate the status field, to be recognizable in
+		 * the log message below.
+		 */
+		unmap.status = 1;
+
+		rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
+					       &unmap, 1);
+		if (rc || unmap.status != GNTST_okay)
+			pr_err_once("gnttab unmap failed: rc=%d st=%d\n",
+				    rc, unmap.status);
 	}
 
 	return 0;