From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sat, 6 Feb 2010 00:16:50 +0000 (-0800)
Subject: Fix potential crash with sys_move_pages
X-Git-Tag: v2.6.31.13~89
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=45468a60ffdcc00758b849e651adc2329c86fd85;p=thirdparty%2Fkernel%2Fstable.git

Fix potential crash with sys_move_pages

commit 6f5a55f1a6c5abee15a0e878e5c74d9f1569b8b0 upstream.

We incorrectly depended on the 'node_state/node_isset()' functions
testing the node range, rather than checking it explicitly.  That's not
reliable, even if it might often happen to work.  So do the proper
explicit test.

Reported-by: Marcus Meissner <meissner@suse.de>
Acked-and-tested-by: Brice Goglin <Brice.Goglin@inria.fr>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/mm/migrate.c b/mm/migrate.c
index 598abad88f976..eebfb79d77489 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -937,6 +937,9 @@ static int do_pages_move(struct mm_struct *mm, struct task_struct *task,
 				goto out_pm;
 
 			err = -ENODEV;
+			if (node < 0 || node >= MAX_NUMNODES)
+				goto out_pm;
+
 			if (!node_state(node, N_HIGH_MEMORY))
 				goto out_pm;