mm/mempolicy.c: fix wrong sp_node insertion

commit 5ca3957510b9fc2a14d3647db518014842f9a2b4 upstream.

n->end is accessed in sp_insert(). Thus it should be update
before calling sp_insert(). This mistake may make kernel panic.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index e2df1c1..3df6d12 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2386,8 +2386,8 @@ restart:
                                *mpol_new = *n->policy;
                                atomic_set(&mpol_new->refcnt, 1);
                                sp_node_init(n_new, n->end, end, mpol_new);
-                               sp_insert(sp, n_new);
                                n->end = start;
+                               sp_insert(sp, n_new);
                                n_new = NULL;
                                mpol_new = NULL;
                                break;