Page migration: Do not accept invalid nodes in the target nodeset

Page migration currently does not check if the target of the move contains
nodes that that are invalid (if root attempts to migrate pages)
and may try to allocate from invalid nodes if these are specified
leading to oopses.

Return -EINVAL if an offline node is specified.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 172abffeb2e386fe08a333051934b73fcd98707a..bb54b88c3d5aaab2752569f046129bea8082f4ec 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -955,6 +955,11 @@ asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode,
                goto out;
        }
 
+       if (!nodes_subset(new, node_online_map)) {
+               err = -EINVAL;
+               goto out;
+       }
+
        err = security_task_movememory(task);
        if (err)
                goto out;