From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751832Ab1AERYf (ORCPT ); Wed, 5 Jan 2011 12:24:35 -0500 Received: from gir.skynet.ie ([193.1.99.77]:55444 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751725Ab1AERYe (ORCPT ); Wed, 5 Jan 2011 12:24:34 -0500 Date: Wed, 5 Jan 2011 17:24:13 +0000 From: Mel Gorman To: Eric B Munson Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, caiqian@redhat.com, stable@kernel.org Subject: Re: [PATCH] Fix handling of parse errors in sysctl Message-ID: <20110105172412.GA29257@csn.ul.ie> References: <1294247329-11682-1-git-send-email-emunson@mgebm.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1294247329-11682-1-git-send-email-emunson@mgebm.net> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 05, 2011 at 10:08:49AM -0700, Eric B Munson wrote: > This patch is a candidate for stable. > > ==== CUT HERE ==== > > When parsing changes to the huge page pool sizes made from userspace > via the sysctl interface, bogus input values are being covered up > by nr_hugepages_store_common and nr_overcommit_hugepages_store > returning 0 when strict_strtoul returns an error. Not just that, it can infinite loop so it's a fairly serious problem. > This patch changes > the return value for these functions to -EINVAL when strict_strtoul > returns an error. > > Reported-by: CAI Qian > > Signed-off-by: Eric B Munson Acked-by: Mel Gorman > --- > mm/hugetlb.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 8585524..5cb71a9 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1440,7 +1440,7 @@ static ssize_t nr_hugepages_store_common(bool obey_mempolicy, > > err = strict_strtoul(buf, 10, &count); > if (err) > - return 0; > + return -EINVAL; > > h = kobj_to_hstate(kobj, &nid); > if (nid == NUMA_NO_NODE) { > @@ -1519,7 +1519,7 @@ static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, > > err = strict_strtoul(buf, 10, &input); > if (err) > - return 0; > + return -EINVAL; > > spin_lock(&hugetlb_lock); > h->nr_overcommit_huge_pages = input; -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab